FOOD- AND WATERBORNE DISEASES
AND ZOONOSES
Kolářová M., EPI Autumn 2019
3. Food- and waterborne diseases and zoonoses
• Anthrax
• Botulism
• Brucellosis
• Campylobacteriosis
• Cholera
• Cryptosporidiosis
• Echinococcosis (hydatid disease)
• Shiga toxin/verocytotoxin-producing Escherichia coli (STEC/VTEC) infection
• Giardiasis
• Hepatitis A
• Leptospirosis
• Listeriosis
• Noroviruses
• Salmonellosis
• Shigellosis
• Toxoplasmosis (congenital)
• Trichinellosis
• Tularaemia
• Typhoid/paratyphoid fever
• Variant Creutzfeldt–Jakob disease (vCJD)
• Yersiniosis
There were only minor fluctuations in
reported cases of three main zoonotic
diseases in the European Union (EU) last
year compared with 2016.
The number of reported cases of
salmonellosis and campylobacteriosis has
remained stable over the past five years,
although listeriosis continues to rise.
Active surveillance through the Foodborne Diseases Active Surveillance Network
(FoodNet) indicates that about 14 cases per 100,000 people are diagnosed each year.
Many more cases go undiagnosed or unreported.
CDC estimates that Campylobacter infection affects more than 1.5 million people in the United
States every year.
Campylobacter infections increased by 13% in 2014, when compared with 2006-2008.
Use of culture-independent tests (CIDTs) to diagnosis Campylobacter infection increased
by 14% in 2014, typically replacing traditional culture-based methods.
Campylobacteriosis is common in Europe.
Campylobacteriosis
• In the European Union (EU)
Cases of campylobacteriosis decreased slightly in 2017
compared with 2016 (246 158 from 246 917),
but it is still the most commonly reported zoonotic
disease in the EU.
• The highest occurrences were detected in chicken
meat (37.4%) and turkey meat (31.5%).
Infections occur throughout the year but are most
common from June to October.
CAMPYLOBACTERIOSIS (Campylobacter spp.) – Case definition
Clinical Criteria
• Any person with at least one of the following three:
• — Diarrhoea
• — Abdominal pain
• — Fever
Laboratory Criteria
• — Isolation of Campylobacter spp. from stool or
blood
• Differentiation of Campylobacter spp. should be
performed if possible
Epidemiological Criteria
• At least one of the following five epidemiological
links:
• — Animal to human transmission
• — Human to human transmission
• — Exposure to a common source
• — Exposure to contaminated food/drinking water
• — Environmental exposure
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and
with an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Etiologic agent
Campylobacter is a gram-negative, microaerophilic genus of bacteria of the
family Campylobacteriacae.
There are more than 20 species of Campylobacter, not all of which cause
human illness.
Approximately 90% of human illness is caused by one species, Campylobacter
jejuni. Less common species, such as C. coli, C. upsaliensis, C. fetus and C.
lari, also cause infection.
• Campylobacter jejuni grows best at 37°C to 42°C, the approximate body
temperature of a bird (41°C to 42°C), and seems to be well-adapted to birds,
which carry the bacteria without becoming ill.
These bacteria are fragile.
They cannot tolerate drying.
Freezing reduces the number of Campylobacter bacteria on raw meat.
Campylobacteriosis
Source are animals such as:
poultry, cattle, pigs, wild birds and wild mammals.
Transmission:
Most cases of Campylobacter infection occur after someone eats raw or undercooked
poultry or eats another food that has been contaminated by raw or undercooked poultry.
It is usually acquired from eating or drinking contaminated food and water; nevertheless, it can
also be caught directly from animals or, rarely, from person to person though contact with
infected faeces. Drinking raw or inadequately pasteurised milk has caused outbreaks of
campylobacteriosis and cases have also been caused by birds pecking at milk in foil-topped
bottles. Untreated surface water in community water supplies or failures in water treatment
and contaminated water in open-topped tanks have also caused campylobacteriosis.
Person-to-person spread can happen, although it is unusual, and is most likely
from children who have diarrhoea or are not toilet-trained.
Susceptibility:
All ages are affected but most cases are in children aged younger than four years and in
young adults.
People at increased risk of Campylobacter infection include those working with farm
animals or meat, travellers abroad (it is a common cause of travellers’ diarrhoea),
gay men and family contacts of cases.
Patients with HIV may be ill for longer and suffer recurrent infections.
Most people who get Campylobacter infection
recover completely within two to five days,
although recovery can take up to 10 days.
Campylobacter infection can result in long-term
consequences such as arthritis, irritable bowel
syndrome (IBS), or Guillain-Barré syndrom
(GBS).
CDC estimates about 1 in every 1,000 reported
Campylobacter illnesses leads to GBS.
A confirmed case is the isolation of Campylobacter
spp. from a clinical specimen.
A probable case is the detection of Campylobacter
spp. in a clinical specimen using a cultureindependent
diagnostic test (CIDT), such as a
polymerase chain reaction test.
Campylobacteriosis - prevention
There is currently no vaccine against Campylobacter infection.
Drinking pasteurised milk and chlorinated drinking water is
important in preventing contamination.
Good hygiene in commercial and domestic kitchens—especially
avoiding cross-contamination—is important as is cooking meat
properly, especially poultry. Conventional disinfectants are active
against Campylobacteriosis.
Doorstep milk should be protected against birds and it is important
to wash hands carefully after contact with faeces, nappies, meat
or animals, including on farm visits.
Human with Campylobacteriosis
Food handlers, healthcare workers and children younger than five
years should stay away from work, nursery or daycare until 48
hours after symptoms have stopped.
Food handlers and healthcare workers should continue to observe
careful hygiene measures, especially hand washing.
Salmonellosis
CDC estimates that approximately 1.35 million illnesses
and 420 deaths occur due to non-typhoidal Salmonella
annually in the United States.
FoodNet reports that the annual incidence of Salmonella
infection in the United States was 15.2 illnesses per
100,000 individuals.
Compared to 2010-2012, the incidence of non-typhoidal
Salmonella infection showed a 9% decrease in 2013.
In the European Union (EU)
After several years of decline, salmonellosis cases in the
EU have flattened out.
In 2017 the number fell slightly from 94 425 to 91 662,
but the downward trend that began in 2008 has stalled in
recent years.
• Salmonella Enteritidis is the most commonly reported
type of Salmonella in humans, causing one in seven
food-borne outbreaks.
EU/EEFA
Etiologic agent
The genus Salmonella is a member of the family Enterobacteriaceae.
Like other Enterobacteriaceae, Salmonellae are Gram-negative, rodshaped
bacilli.
The genus Salmonella can be divided into two species (S. enterica and S.
bongori), based on their phenotypic profile. S. enterica can be further
divided into six subspecies using their phenotypic profile.
The most common serotypes of Salmonella that cause human infection are
Enteritidis, Typhimurium, Newport, and Javiana.
These Salmonella serotypes account for about half of culture-confirmed
Salmonella isolates reported by public health laboratories.
SALMONELLOSIS (Salmonella spp. other than Salmonella typhi and
Salmonella paratyphi) – Case definition
Clinical Criteria
• Any person with at least one of the
following four:
• — Diarrhoea
• — Fever
• — Abdominal pain
• — Vomiting
Laboratory Criteria
• Isolation of Salmonella (other than
Salmonella typhi and Salmonella
paratyphi) from stool, urine, body site
(e.g. infected wound) or any normally
sterile body fluids and tissues (e.g.
blood, CSF, bone, synovial fluid, etc.)
Epidemiological Criteria
• At least one of the following five
epidemiological links:
• — Human to human transmission
• — Exposure to a common source
• — Animal to human transmission
• — Exposure to contaminated
food/drinking water
• — Environmental exposure
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria
and with an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Source.
Salmonella live in the intestinal tracts of humans and other animals, including poultry and other
birds, amphibians, and reptiles. Salmonella may be found in the feces of some animals, and
people can become infected if they do not wash their hands after contact with animals or animal
feces.
Many animals can carry Salmonella germs but appear perfectly healthy and clean.
Transmission:
Salmonella is usually transmitted to humans by eating foods contaminated with small amounts of
animal feces. Contaminated foods usually look and smell normal. They are often foods of animal
origin, such as beef, poultry, milk, fish, or eggs, but any food, including vegetables and fruit or
processed foods, may become contaminated.
Foods can also be contaminated in the kitchen. Drippings from raw meat or poultry can
contaminate surfaces and other foods in the refrigerator or shopping cart. When raw meat or
poultry are prepared with a cutting board and knife without being washed thoroughly between
uses, they can contaminate other foods.
When preparing raw meat or poultry, food handlers can transfer Salmonella on their hands to
other foods if they do not wash their hands between food preparation steps. Food handlers who
do not wash their hands with soap after using the bathroom can also contaminate food with
Salmonella.
Salmonella infection is more common in the summer months (June, July, and August) than
winter.
Susceptibility:
• Children under 5 years old are the most likely to get a Salmonella
infection.
• Infants who are not breast fed are more likely to get a Salmonella
infection.
• Children who are 5 years old and younger, adults over 65 years old,
and people with weakened immune systems are the most likely to
have severe infections.
• Certain medications (for example, medications to reduce stomach
acid) can increase the risk of Salmonella infection
Listeriosis
• Listeriosis is a disease caused by Listeria monocytogenes. The disease primarily
causes problems in pregnant women, newborns, and adults with a weakened
immune system.
Listeria bacteria are ubiquitous in the environment, and food-borne outbreaks have been
detected worldwide. Many animals carry the bacteria in their faeces.
• After exposure (via contaminated food) most healthy adults do not develop any
symptoms, except in the case of pregnant women. After an incubation period of
about three weeks pregnant women may suffer from a self-limiting influenza-like
illness which may affect the uterus. In that case, it can lead to death of the foetus and
consequent abortion or to a dramatic picture of congenital listeriosis in the newborn.
In addition, listeriosis in adults with weakened immune system and the elderly may
lead to meningitis, brain infection, and severe blood infection. All clinical
presentations are treatable with prolonged courses of antibiotics, but the prognosis of
the most serious ones is poor.
Control measures should be aimed at the farm and food-processing level, in order to
prevent contamination of food products. Preventive measures include providing
appropriate information for consumers on how to minimise the risk of ingesting food
contaminated by Listeria.
•
• In the European Union (EU)
• Cases of listeriosis decreased slightly
in 2017: 2 480 infections were reported, against 2 509 in 2016.
However, the trend has been upward over the past five
years.
The group most affected by the disease in 2017 was the
elderly, particularly those over 84. In this age group, the
listeriosis fatality rate was 24%, while overall in the EU,
the infection was fatal for one in every 10 patients.
The highest levels of Listeria monocytogenes were
detected in fish and fishery products (6%), followed by
ready-to-eat salads (4.2%).
Listeriosis
• Symptoms
Listeriosis can cause a range of symptoms. Some patients can have no
symptoms at all. Previously well, non-pregnant people often get symptoms
of acute gastroenteritis—inflammation of the stomach and intestines. This
can cause headache, fever, abdominal pain, sleepiness, nausea and
diarrhoea. Fatigue, aching muscles, painful joints, vomiting and a sore throat
may also occur.
• Complications
Listeriosis can also cause serious illness, most often in those with long-term
health conditions, the elderly, or people whose immune systems are
compromised. Severe symptoms can include the following: blood poisoning;
inflammation of the brain and its lining; abscesses; inflammation of the lining
of the heart; and infected or inflamed joints. Pregnant women who get the
infection may only have mild illness, but can suffer miscarriage, premature
delivery or stillbirth. Newborn babies can also suffer from severe symptoms,
including meningitis, which can lead to death.
Listeriosis
• Ways to catch listeriosis
The bacteria that cause listeriosis are widespread in the environment
and can be found in soil, surface water, vegetation and a range of wild
and domestic animals. Most humans catch the infection by eating
contaminated food. The bacteria can grow at low temperatures and are
tolerant of salt and therefore can survive in processed, preserved and
refrigerated foods. Foods that have been associated with spreading
listeriosis include the following: processed meat and fish, cold meats
and hot dogs; dairy products, such as soft cheese, butter and milk,
especially if unpasteurised; and pre-prepared salads, sandwiches and
salads. Other sources of infection include direct contact from animals
or the environment. Pregnant women can pass the infection to their
babies during birth or through the placenta.
• People most at risk
Reported cases in Europe are highest among those over 65 and
children younger than four.
Listeriosis
• Diagnosis
Laboratory tests are carried out on samples of
blood or cerebrospinal fluid to diagnose the
infection. Laboratory tests are also carried out on
food and environmental samples to look for
Listeria.
• Treatment
Antibiotics can be used to treat patients.
Listeriosis
• Prevention:
Pasteurising dairy products is important as the process kills Listeria. Cookchill
and ready-to-eat foods should not be stored for too long and should be
thoroughly reheated before serving.
• Raw vegetables, fruits and salads should be thoroughly washed before
eating.
• Pregnant women and people whose immune systems are compromised are
advised to avoid soft cheeses, pâté and pre-packed salads, contact with
pregnant or newborn animals and silage. Hand washing is effective at
reducing the risk of gastroenteritis from many organisms and may be made
even more effective by using antibacterial soap. There is no vaccine against
listeriosis.
Antrax
• Anthrax is…
…a disease that humans can catch from animals.
It causes serious illness. It used to be largely
occupationally related but has also been used
deliberately in bio-terrorist attacks.
ANTHRAX (Bacillus anthracis) – Case definition
Clinical Criteria
• Any person with at least one of the following clinical forms:
• Cutaneous anthrax
• At least one the following two:
• — Papular or vesicular lesion
• — Depressed black eschar with surrounding oedema
• Gastrointestinal anthrax
• — Fever or feverishness
• AND at least one of the following two:
• — Severe abdominal pain
• — Diarrhoea
• Inhalational anthrax
• — Fever or feverishness
• AND at least one of the following two:
• — Acute respiratory distress
• — Radiological evidence of mediastinal widening
• Meningeal/meningoencephalitic anthrax
• — Fever
• AND at least one of the following three:
• — Convulsions
• — Loss of consciousness
• — Meningeal signs
• Anthrax septicaemia
Laboratory Criteria
• — Isolation of Bacillus anthracis from a clinical specimen
• — Detection of Bacillus anthracis nucleic acid in a clinical specimen
• Positive nasal swab without clinical symptoms does not contribute to a
confirmed diagnosis of a case
• Epidemiological Criteria
• At least one of the following three
epidemiological links:
• — Animal to human transmission
• — Exposure to a common source
• — Exposure to contaminated food/drinking
water
• Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and with
an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Antrax
Symptoms
The symptoms depend on how the anthrax was acquired by the infected person.
Close physical contact with infected livestock or contaminated dead animal products
can cause anthrax affecting the skin also known as cutaneous anthrax. This is the
most common form of the disease. A small pointed and inflamed elevation appears
on the skin, usually on the face, hands or forearms. Over 2–3 days, this ulcerates to
become a dry, black, painless scab, surrounded by a ring of small cysts. This is
always accompanied by substantial swellings containing fluid, which extend a long
way from the scab. The scab dries and falls off within 1–2 weeks, with little scarring.
Patients with cutaneous anthrax usually recover, provided they receive prompt
treatment with antibiotics.
Swallowing anthrax can cause gastrointestinal anthrax, the form most common in
children. Gastrointestinal anthrax can affect either the upper throat or the intestines.
The form affecting the throat usually starts with a flu-like illness with a high
temperature, followed by throat ulcers and a visible swelling of the neck. The form
affecting the intestines causes ulcers in the bowel, leading to nausea and vomiting,
loss of appetite and high fever with abdominal pain, vomiting blood and bloody
diarrhoea. Anthrax which is breathed in causes inhalational anthrax. This illness
comes in two phases beginning with non-specific mild fever, malaise, muscle aches,
dry cough and chest pain; disorientation is also common. Within 1–6 days, the illness
progresses to the second phase with fever, acute shortness of breath, a harsh,
grating sound when breathing and blue-tinged skin, rapidly leading to respiratory
failure, shock, a drop in body temperature and death, if untreated.
Antrax
Complications
Complications are rare in cutaneous anthrax
although secondary infections are possible.
Gastrointestinal and inhalational anthrax can lead
to inflammation of the brain: a flu-like illness,
sometimes with an intense headache, rapidly
progresses to seizures, delirium and coma, with
collapse and sometimes death.
Antrax
Ways to catch anthrax
Anthrax spores can be found in soil and animals, like cows,
can then acquire the infection while grazing. Humans can
catch the spores by eating contaminated or insufficiently
cooked meat, through contaminated flies that bite, by a having
a break in the skin and then being in contact with
contaminated animal skins, bones, wool, hair or tusks or by
breathing in spores (e.g., in wool sorting, bonemeal or hide
processing factories). Anthrax has also been deliberately
released as a bio-terrorist weapon.
People most at risk
Those most at risk of cutaneous anthrax are butchers, famers,
vets or people working in the animal hide industry.
Antrax
Diagnosis
Anthrax can be detected by doing laboratory tests on specimens from
an infected person.
Treatment
Anthrax can be treated with antibiotics. Respiratory support in an
intensive care unit (ICU) is likely to be necessary for cases of
inhalational anthrax.
How to avoid getting anthrax
Vaccines are available that protect against anthrax.
Vaccination is recommended for vets, abattoir workers, those working
with animal hides or furs, laboratory workers and armed forces in
areas of high risk of exposure. Animals can be vaccinated to prevent
them from being infected and passing the spores onto humans.
Botulism
Botulism is a serious paralytic illness caused by a nerve toxin produced by
the bacterium Clostridium botulinum. The disease may occur after eating
foods containing the toxin or due to development of the spores within the
intestine of young children or within wounds.
Food botulism is the dominating form of the disease, and paralytic
symptoms generally appear after an incubation period of 12–36 hours (up
to several days) after consumption of the toxin-containing food. The
symptoms may be very severe, and require intensive-care treatment and
the administration of an anti-toxin. Even where these are available,
between 5 and 10 % of the patients die.
Due to the extremely high potency of the toxin, botulism is included among
the potential bio-terrorist threats. Following laboratory accidents, the toxin
has also caused symptoms on inhalation, with a substantially reduced
incubation period.
BOTULISM (Clostridium botulinum) - Case definition
Clinical Criteria
• Any person with at least one of the following clinical
forms:
• Food-borne and wound botulism
• At least one of the following two:
• — Bilateral cranial nerve impairment (e.g. diplopia,
blurred vision, dysphagia, bulbar weakness)
• — Peripheral symmetric paralysis
• Infant botulism
• Any infant with at least one of the following six:
• — Constipation
• — Lethargy
• — Poor feeding
• — Ptosis
• — Dysphagia
• — General muscle weakness
• The type of botulism usually encountered in infants
(< 12 months of age) can affect children also over
12 months of age and occasionally adults, with
altered gastrointestinal anatomy and microflora
Laboratory Criteria
• At least one of the following two:
• — Isolation of Clostridium botulinum for infant
botulism (stool) or wound botulism (wound) (isolation
of Clostridium botulinum in stool of adults not relevant
for the diagnosis of food-borne botulism)
• — Detection of botulinum toxin in a clinical specimen
Epidemiological Criteria
• At least one of the following two epidemiological links:
• — Exposure to a common source (e.g. food, sharing
of needles or other devices)
• — Exposure to contaminated food/drinking water
• Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and with an
epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the laboratory
criteria
BotulismSymptoms
Botulism causes paralysis by affecting the nerves which allow the brain to
stimulate muscles and part of the central nervous system. It initially affects
the nerves in the skull and may cause blurred vision, difficulty swallowing,
double vision, stammering or stuttering, vocal disturbance, drooping eyelids,
facial weakness and weakness of the tongue. Weakness in the neck and
arms follows, after which the respiratory and lower body muscles are
affected. Respiratory problems may be severe enough to need ventilation in
hospital. Other symptoms may include dry mouth, urinary problems and
dysfunction of the stomach, intestines, heart and blood vessels. Patients do
not usually have a fever, and have no loss of sensory functions or
awareness. Botulism caught from food usually affects the stomach and
intestines, causing nausea, vomiting, constipation, diarrhoea and abdominal
cramps. Botulism in a wound causes inflammation around the wound,
followed by low blood pressure and circulatory collapse. Patients with wound
botulism often look and feel quite well before deteriorating dramatically over
a few hours. Babies with botulism may have constipation, lethargy, feeding
difficulties, floppy muscles, increased drooling and a weak cry.
Botulism
Ways to catch botulism
Botulism spores are widespread in the environment and can
be found in dust, soil, untreated water and the digestive tracts
of animals and fish. Foods that have led to botulism
outbreaks have included the following: meat products, such
as sausage and cured ham; canned, vacuum-packed,
smoked or fermented fish products; vegetables preserved by
canning or stored in oil; baked potatoes; honey; and cheese.
Many outbreaks have occurred due to home-preserved foods.
Intestinal or infant botulism usually takes place after
swallowing botulinum spores, sometimes from food, which
then produce toxins in the gut. Wound botulism usually
happens from inoculating botulinum spores which then grow
in the inoculation wound and produce toxins.
Botulism
People most at risk
Rates of botulism in the EU are generally low, with
around 200 cases each year (0.03 cases per 100
000 people). The highest levels of cases over the
past 10 years have been reported from Poland and
Lithuania. Wound botulism in intravenous drug users
is now the most common type of botulism in some
European countries, such as the UK and Ireland.
Infant botulism, which is very rare in Europe, usually
affects children younger than two, with most being
under six months old.
Botulism
Diagnosis
Laboratory tests can detect botulinum toxin in
faeces, serum, stomach contents, a swab from a
wound or in samples from contaminated food.
• Treatment
Patients need to be admitted to hospital for
investigation and treatment. Botulinum antitoxin is
available and reduces the length of illness and
fatality rates, but may have serious side effects.
Treatment can be given based on a doctor’s
diagnosis of symptoms, without waiting for laboratory
confirmation. Wound botulism can be treated with
antibiotics and surgery to remove dead tissue.
Botulism
How to avoid getting botulism
There is no routine vaccination against botulism. Care should be taken
when canning food, either commercially or at home, and when preserving
fish, meat and vegetables to make sure botulinum is destroyed before
storage. Do not eat food from containers that are obviously bulging (which
could be caused by gas from the botulinum) or containers that are
damaged. Avoid tasting food that might be spoiled. Keep food that has not
been completely processed in the fridge. Boiling food for ten minutes
before eating it would inactivate the toxin in home-canned foods. Potential
botulism cases should get urgent medical response and investigation.
Prevention work with intravenous drug users is also important.
What to do if you have botulism
Person-to-person spread is unlikely but it is sensible for carers and
laboratory staff to wear personal protective equipment like gloves and
goggles. Patients and their contacts do not need to stay away from work if
they are well enough. People who have acquired botulism from
contaminated food should be asked to give a history of everything they
have eaten in the past five days before they became ill, especially canned
or preserved foods..
Brucellosis
Brucellosis is an infection caused by Brucella bacteria. The common reservoirs
for Brucella bacteria that may infect humans are cattle, dogs, sheep, goats,
and pigs. Brucellosis occurs worldwide but the Mediterranean region has
been particularly affected. Humans become infected by direct or indirect
contact with animals or with contaminated animal products (including
unpasteurised milk and dairy products) or by the inhalation of aerosols.
After an incubation period of five to 60 days, symptoms may appear either
acutely or insidiously. Untreated, the disease may become chronic. The
various symptoms are both general (fever, weakness, joint pain) and organspecific
(including infections in the brain infection and heart valves).
Untreated, brucellosis can lead to death. Prolonged antibiotic treatment is
usually effective.
Control measures include animal vaccination and/or test-and-slaughter of
infected animals, as well as pasteurisation of milk and dairy products.
BRUCELLOSIS (Brucella spp.) – Case definition
Clinical Criteria
• Any person with Fever
• And at least one of following seven:
• — Sweating (profuse, malodorous, specially
nocturnal)
• — Chills
• — Arthralgia
• — Weakness
• — Depression
• — Headache
• — Anorexia
Laboratory Criteria
• At least one of the following two:
• — Isolation of Brucella spp. from a clinical
specimen
• — Brucella specific antibody response
(Standard Agglutination Test, Complement
Fixation, ELISA)
Epidemiological Criteria
• At least one of the following four epidemiological
links:
• — Exposure to contaminated food/drinking
water
• — Exposure to products from a contaminated
animal (milk or milk products)
• — Animal to human transmission (contaminated
secretions or organs e.g. vaginal discharge,
placenta)
• — Exposure to a common source
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and with
an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Cholera
Cholera is an acute diarrhoeal infection caused by the bacterium Vibrio
cholera of serogroups O1 or O139. Humans are the only relevant reservoir,
even though Vibrios can survive for a long time in coastal waters
contaminated by human excreta.
Consumption of contaminated water and food, especially seafood eaten
under-cooked, results in infection. After a short incubation period of less
than five days, the typical symptoms might develop, characterised by
vomiting and watery diarrhoea. In most cases, though, symptoms are mild
or absent and infected individuals become carriers with no symptoms.
With timely treatment (fluid replacement and antibiotics), less than 1% of
patients with symptoms die. The disease has not been endemic in Europe
for a long time, and thanks to high hygiene standards the potential for
imported cases to generate further ones is low.
•
CHOLERA (Vibrio cholerae) – Case definition
Clinical Criteria
• Any person with at least one of the following
two:
• — Diarrhoea
• — Vomiting
Laboratory Criteria
• — Isolation of Vibrio cholerae from a clinical
specimen
• AND
• — Demonstration of O1 or O139 antigen in
the isolate
• AND
• — Demonstration of cholera-enterotoxin or
the cholera-enterotoxin gene in the isolate
Epidemiological Criteria
• At least one of the following four
epidemiological links:
• — Exposure to a common source
• — Human to human transmission
• — Exposure to contaminated food/drinking
water
• — Environmental exposure
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and
with an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Cholera
an illness caused by bacteria called Vibrio cholerae. It causes
diarrhoea and can lead people to become severely
dehydrated very quickly, which can be fatal. It is a major
public health problem in many parts of the world and a threat
to Europeans travelling to these areas.
• Symptoms
Cholera can range in severity from a mild illness which may
show no symptoms through to very severe symptoms. The
first signs are nausea and discomfort in the abdomen,
followed by sudden watery diarrhoea and vomiting. Vomiting
tends to disappear after around 12 hours, although the
diarrhoea may continue. Cholera often causes people to
painlessly loose large amounts of liquid stools – often called
“rice water” stools because of their appearance. People with
cholera often have extremely painful muscle cramps.
Cholera
• Complications
If cholera is untreated, severe dehydration and
“hypovolemic” shock can happen, which leads to
symptoms including sunken eyes, wrinkled skin, a
very fine and scarcely perceptible pulse,
undetectable blood pressureand reduced levels of
consciousness. Severe untreated cholera can cause
kidney failure and, in 50% of cases, death. In
children, a condition called hypoglycaemia (low blood
sugar) can occur which can be severe and cause
convulsions and coma. In pregnant women, cholera
can cause miscarriages and premature birth.
Cholera
• Ways to catch cholera
Cholera is mostly a waterborne disease. It is caught by swallowing water
that has been contaminated with bacteria. It also possible to catch the
disease by eating contaminated seafood or food that became
contaminated by being handled or prepared by someone with the
disease. Fruit and vegetables have also been contaminated when land
has been irrigated with raw sewage.
• People most at risk
Cholera occurs mainly in countries with inadequate sanitation and lack of
clean drinking water, or where there have been wars or natural disasters.
The most common risk factors for cholera are water source
contamination, heavy rainfall and flooding and population dislocation. It is
most common in South East Asia, particularly the Indian sub-continent,
although outbreaks have happened often where it has spread to other
parts of the world. The disease is currently also common in several
countries in sub-Saharan Africa and Latin America. It affects all ages but
children are at the highest risk for acquiring severe disease.
Cholera
• Diagnosis
Cholera can be confirmed by testing a sample of a patient’s stools in a
laboratory. Rapid tests are also being developed, which do not need to be
done in laboratories –. However, where there are outbreaks of large
numbers of cases, laboratory tests would not be carried out on all patients
and doctors would be able to diagnose patients based on their diarrhoea
and vomiting symptoms.
• Treatment
As previously mentioned, if cholera is not treated, up to 50% of people who
have it can die. However, as long as treatment is given, this is reduced to
around 1% of cases. Rapidly rehydrating patients is the most important
treatment for cholera. The majority of cases can be rehydrated by drinking
Oral Rehydration Salt solution. Severely dehydrated patients will need
intravenous fluids and may also be treated with antibiotics. Using antidiarrhoeal
drugs is not recommended in patients with cholera. Infection
control measures are important with cholera patients, because the bacteria
are highly infectious. Patients in hospital or being cared for at home should
be isolated and strict hygiene measures implemented to reduce the risk of
spreading the infection.
Cholera
• How to avoid getting cholera
In areas where cholera is more common, improved sanitation
and water supplies and food hygiene measures are important
in reducing the spread of cholera. Water should be chlorinated
or boiled before it is considered safe to drink. Although this is
a low risk, travellers to countries where cholera is more
common should be aware of the possibility of contracting it
and drink only boiled or mineral water.
• A vaccine is available that is effective against cholera.
Vaccine against cholera
A vaccine consisting of killed whole-cell V. cholerae O1 in
combination with a recombinant B-subunit of cholera toxin
(WC/rBS) has been marketed since the early 1990s.
This killed vaccine is well tolerated and confers high-level
(85– 90%) protection for 6 months after the second
immunization in all vaccinees aged more than 2 years.
Three years after immunization the level of protection is still
about 50% in vaccinees who were 5 years or older at the time
of vaccination.
Vaccine against cholera
Primary immunization consists of two oral doses 7–14 days apart for
adults and children aged 6 years and over.
For children aged 2–5 years, three doses are recommended. Intake of
food and drinks should be avoided for 1 hour before and after
vaccination.
If the second dose is delayed for more than 6 weeks, vaccination should
be restarted.
Following primary immunization, protection against cholera may be
expected after about 1 week.
Booster doses are recommended after 2 years for adults and children
aged 6 years or more, and every 6 months for children aged 2–5 years.
The vaccine is not licensed for children under 2 years of age.
Vaccine against cholera
In studies of travellers to countries or areas reporting
cholera outbreaks, WC/rBS was found also to induce
approximately 50% short-term protection against diarrhoea
caused by enterotoxigenic Escherichia coli (ETEC).
TYPHOID/PARATYPHOID FEVER (Salmonella typhi/paratyphi) Case
definition
Clinical Criteria
• Any person with at least one of the following
two:
• — Onset of sustained fever
• — At least two of the following four:
• — Headache
• — Relative bradycardia
• — Non-productive cough
• — Diarrhoea, constipation, malaise or
abdominal pain
• Paratyphoid fever has the same symptoms as
typhoid fever, however usually a milder course
Laboratory Criteria
• — Isolation of Salmonella typhi or paratyphi
from a clinical specimen
Epidemiological Criteria
• At least one of the following three
epidemiological links:
• — Exposure to a common source
• — Human to human transmission
• — Exposure to contaminated food/drinking
water
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and
with an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Currently, two typhoid vaccines of demonstrated safety and efficacy are available on
the international market:
• The oral vaccine based on the live, attenuated mutant strain of S. typhi Ty21a
(Ty21a vaccine), is supplied in enteric coated capsules. In Australia and Europe,
three tablets are given on days 1, 3, and 5; this series is repeated every year for
individuals travelling from nonendemic to endemic countries, and every 3 years for
individuals living in countries or areas at risk. In North America, four tablets are
given on days 1, 3, 5, and 7 and revaccination is recommended only after 7 years
(Canada) or 5 years (USA) for all, regardless of typhoid fever risk in the country or
area of residence. The duration of protection following Ty21a immunization is not
well defined and may vary with vaccine dose and possibly with subsequent
exposures to S. typhi (natural booster).
• The injectable Vi capsular polysaccharide vaccine (ViCPS vaccine) is given
intramuscularly in a single dose. Protection is induced about 7 days after the
injection. In countries or areas at risk, the protective efficacy 1.5 years after
vaccination is about 72%; after 3 years it is about 50%. The vaccine is licensed for
individuals aged >2 years. To maintain protection, revaccination is recommended
every 3 years.
The injectable Vi capsular polysaccharide vaccine (ViCPS
vaccine) is given intramuscularly in a single dose.
Protection is induced about 7 days after the injection. In
countries or areas at risk, the protective efficacy 1.5 years
after vaccination is about 72%; after 3 years it is about
50%. The vaccine is licensed for individuals aged >2
years. To maintain protection, revaccination is
recommended every 3 years.
A combined typhoid/hepatitis A vaccine is also available in
some countries.
Cryptosporidiosis
• Cryptosporidia are intestinal parasites infecting a variety of animals (e.g. cattle,
sheep, rodents, cats and dogs, but also birds, fish and reptiles). Human infections
occur due to Cryptosporidium parvum, a species that also affects domestic animals.
In humans, infections without symptoms are common. Especially healthy individuals,
may, after an incubation period averaging one week, get a diarrhoea that
spontaneously resolves over a couple of weeks. By contrast, patients with impaired
immune system may develop profuse, life-threatening, watery diarrhoea that is very
difficult to treat with currently available drugs.
Person-to-person or animal-to-person disease transmission occurs mainly through
contaminated water and food. Cryptosporidium eggs (oocysts) can survive for
months in moist soil or water and survive harsh environmental conditions (e.g. heat,
cold, droughts) for extended periods of time.
Outbreaks have been reported in hospitals, day-care centres, within households,
among bathers (affecting participants in water sports in lakes and swimming pools),
and in municipalities with contaminated public water supplies. Water distribution
systems are particularly vulnerable to contamination with Cryptosporidium, which can
survive most disinfection procedures such as chlorination
CRYPTOSPORIDIOSIS (Cryptosporidium spp.) – Case definition
Clinical Criteria
• Any person with at least one of the following
two:
• — Diarrhoea
• — Abdominal pain
Laboratory Criteria
• At least one of the following four:
• — Demonstration of Cryptosporidium oocysts
in stool
• — Demonstration of Cryptosporidium in
intestinal fluid or small-bowel biopsy
specimens
• — Detection of Cryptosporidium nucleic acid
in stool
• - Detection of Cryptosporidium antigen in
stool
Epidemiological Criteria
• One of the following five epidemiological
links:
• — Human to human transmission
• — Exposure to a common source
• — Animal to human transmission
• — Exposure to contaminated food/drinking
water
• — Environmental exposure
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and
with an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Cryptosporidiosis
• Symptoms
The most common symptom of cryptosporidiosis is acute,
watery diarrhoea. Pain in the abdomen may also occur, along
with other symptoms like malaise, headache and fever. The
disease is usually self-limiting, but can last up to 14 days and
can cause significant weight loss. In humans, the illness can
vary in severity from no symptoms at all to those who suffer
from persistent diarrhoea, with up to 40% of cases suffering a
return of diarrhoea after recovering from the initial illness.
• Complications
In children, especially in developing countries, cryptosporidiosis
can cause persistent diarrhoea and lead to wasting and stunted
growth. People whose immune systems are deficient, including
patients with HIV and AIDS, can also develop a more severe
and persistent infection.
Cryptosporidiosis
Ways to catch cryptosporidiosis
Cryptosporidium parasites can be caught by swallowing
infected water (either drinking water or through leisure
activities), eating contaminated food, direct contact with animals
carrying the germs, or passed from person to person by direct
contact. Drinking water is a frequent source of infection and
causes outbreaks around the world. This occurs where water is
contaminated with sewage or waste water overflow, or if there
has been a technical failure at a water treatment plant. Personto-person
infection is also common and Cryptosporidium can be
easily spread in households, nurseries and schools. Changing
nappies has been identified as a significant risk factor. In
Europe international travel, contact with another case, contact
with cattle, use of swimming pools and toileting of children
younger than five years have all been shown to be risk factors
for contracting cryptosporidiosis.
Cryptosporidiosis
People most at risk
Cryptosporidiosis occurs worldwide but is a leading
cause of persistent diarrhoea in tropical, developing
areas, particularly in children and people with HIV
infection. Everyone is susceptible to the infection but
the highest numbers of cases are found in children,
with those aged younger than two years at the most
risk.
Cryptosporidiosis
Diagnosis
Cryptosporidiosis can be confirmed by carrying out
laboratory tests on a sample of faeces from an
infected patient.
• Treatment
In most generally healthy people, treatment may not
be necessary for cryptosporidiosis as it is usually selflimiting.
As with all illness causing diarrhoea, it is
important to monitor patients to make sure they do not
become dehydrated. Drugs are available that may be
used to treat patients who develop persistent
diarrhoea.
Cryptosporidiosis
How to avoid getting cryptosporidiosis
Good quality drinking water, swimming pool hygiene and
general hygiene measures are all important in preventing
cryptosporidiosis. Good hand-washing, taking care when
preparing food and carefully disposing nappies are all important
in limiting the spread of infection. People whose immune
systems are compromised should avoid contact with animals
with diarrhoea and young pets, and avoid swallowing water
when swimming. If drinking water supplies are affected, water
should be boiled before drinking.
• What to do if you have cryptosporidiosis
Children who have cryptosporidiosis symptoms should stay
away from schools or daycare centres until 48 hours after the
diarrhoea has stopped. If you have had cryptosporidiosis, you
should avoid using public swimming pools for two to three
weeks after you have recovered from the symptoms.
Echinococcosis
Echinococcosis is a zoonotic disease (transmitted from animals to humans) caused by
the larval stage (hydatid cyst) of tapeworms. Eggs are excreted in the faeces of
infected dogs and foxes and can be ingested by humans either by close contact with
these animals or through contaminated food.
• The most common location of cysts is the liver, but cysts may develop in almost any
organ, including lungs, kidneys, spleen, nervous tissue, etc, years after the ingestion
of the echinococcus eggs. In the case of cystic disease, symptoms usually appear
due to the large size of the cysts. Cysts in the lungs invades tissues in a cancer-like
fashion and if untreated always leads to death.
• Patients are treated with surgery and the specific anti-helminthic drugs. The disease
occurs in areas where dogs have access to animal inner organs, usually of sheep
and cattle (intermediate hosts), containing cysts. The lung form is restricted to
northern countries, where foxes abound.
• Poor hand hygiene, close contact with infected animals and consumption of
undercooked, unwashed food contaminated with echinococcus eggs (e.g.
vegetables) are all risk factors.
•
ECHINOCOCCOSIS (Echinococcus spp.) – Case definition
Clinical Criteria
• Not relevant for surveillance purposes
Diagnostic Criteria
• At least one of the following five:
• — Histopathology or parasitology
compatible with Echinococcus
multilocularis or granulosus (e.g. direct
visualisation of the protoscolex in cyst fluid)
• — Detection of Echinoccocus granulosus
pathognomonic macroscopic morphology of
cyst(s) in surgical specimens
• — Typical organ lesions detected by
imaging techniques (e.g. computerised
tomography, sonography, MRI) AND
confirmed by a serological test
• — Echinococcus spp. specific serum
antibodies by high-sensitivity serological
test AND confirmed by a high specificity
serological test
• — Detection of Echinococcus multilocularis
or granulosus nucleic acid in a clinical
specimen
Epidemiological Criteria NA
Case Classification
• A. Possible case NA
• B. Probable case NA
• C. Confirmed case
• Any person meeting the diagnostic
criteria
Echinococcosis
Symptoms
People who are infected with echinococcosis usually do not have any
symptoms. Symptoms are usually caused when the cysts formed by the
infection restrict or compress other parts of the body. Cysts can also leak
and cause secondary bacterial infection in the body, abscesses or immune
reactions. People get echinococcosis by swallowing the eggs of parasites
after eating contaminated food. The eggs hatch into tapeworms in the
person’s intestines and these pass through the membranes lining the body
and get into the circulation. The tapeworms turn into cysts in the intestines
and bowels which can grow and multiply, especially in the liver or lungs.
However, it can also spread beyond the liver to any organ including the
brain, heart and bones.
• Complications
Complications can include various diseases of the liver and the parts of the
body around the liver. If cysts leak or rupture, they can cause allergic
reactions which are sometimes severe.
Echinococcosis
Ways to catch echinococcosis
People get echinococcosis by swallowing the eggs of
parasites when they eat contaminated food or drink
water contaminated with the faeces of animals which
have been infected with the tapeworm. The infection is
most often spread from dogs, wolves and foxes but
can also come from sheep, goats, cattle, camels and
horses. Infected humans do not excrete eggs.
• People most at risk
The parasites that cause echinococcosis are found all
over the world. Studies have shown that the infection
tends to more often affect older people rather than
children. Dog owners and people who work with
sheep, goats or cows can be more at risk.
Echinococcosis
Diagnosis
Most of the time, untreated cysts remain undetected and are
often found by chance when other complaints are being
investigated. X-rays and ultra-sound scans can detect the cysts
caused by echinococcosis and a biopsy can detect the
infection.
• Treatment
Usually, treatment is only offered to those who are suffering
symptoms as a result of the cysts caused by echinococcosis.
These can either be treated surgically, by chemotherapy or by
using ultrasound scans to guide a doctor to remove the cyst
fluid using a needle.
• How to avoid getting echinococcosis
Good hygiene measures are important to avoid getting
echinococcosis. Vaccines are available for animals to reduce
the risk of their spreading the parasite to humans.
Escherichia coli (E.coli)
Escherichia coli (E.coli) are very common bacteria in
the gastrointestinal tract, and part of the normal
bacterial flora. However, some E.coli strains are
able to produce a toxin that could produce serious
infection. The main reservoir of such E.coli strains is
grass-feeding animals, cattle in particular. Their
meat might become contaminated by faecal matter
due to poor processing methods during slaughter,
and their faeces might end up contaminating other
foods (e.g. milk, vegetables) and water.
SHIGA TOXIN/VEROCYTO-TOXIN PRODUCING ESCHERICHIA COLI
INFECTION (STEC/VTEC) – Case definition
Clinical Criteria
• STEC/VTEC diarrhoea
• Any person with at least one of the following two:
• — Diarrhoea
• — Abdominal pain
• HUS
• Any person with acute renal failure and at least one of the following
two:
• — Microangiopatic haemolytic anaemia
• — Thrombocytopenia
Laboratory Criteria
• At least one of the following four:
• — Isolation of an Escherichia coli strain that produces Shigatoxin (Stx)
or harbours stx1 or stx2 gene(s)
• — Isolation of non-sorbitol-fermenting (NSF) Escherichia coli O157
(without Stx or stx gene testing)
• — Direct detection of stx1 or stx2 gene(s) nucleic acid (without strain
isolation)
• — Direct detection of free Stx in faeces (without strain isolation)
• Only for HUS the following can be used as laboratory criterion to
confirm STEC/VTEC:
• — Escherichia coli serogroup-specific (LPS) antibody response
• Isolation of an STEC/VTEC strain and additional characterisation by
serotype, phage type, eae genes, and subtypes of stx1/stx2 should be
performed if possible
Epidemiological Criteria
• At least one of the following five epidemiological
links:
• — Human to human transmission
• — Exposure to a common source
• — Animal to human transmission
• — Exposure to contaminated food/drinking water
• — Environmental exposure
Case Classification
• A. Possible case of STEC-associated HUS
• Any person meeting the clinical criteria for HUS
• B. Probable case of STEC/VTEC
• Any person meeting the clinical criteria and with an
epidemiological link
• C. Confirmed case of STEC/VTEC
• Any person meeting the clinical and the laboratory
criteria
Escherichia coli (E.coli)
Humans acquire the infection by consuming contaminated food
or water. Following an incubation period of about 3–4 days, a
variety of gastrointestinal symptoms appear, ranging from
mild to severe bloody diarrhoea, mostly without fever.
However, about 8% of patients (children under five years old
and the elderly being the most susceptible) may develop
“haemolytic uraemic syndrome” (HUS), characterised by
acute kidney failure, bleeding and neurological symptoms.
Antibiotic therapy is not helpful (it might even favour HUS
development). The death rate of HUS is about 3–5%.
Shiga toxin-producing E. coli (STEC) is a group of pathogenic
Escherichia coli strains capable of producing Shiga toxins, with the
potential to cause severe enteric and systemic disease in humans.
The full serotype is usually defined by determining both O and H
antigens. There are around 200 different E. coli O serotypes
producing Shiga toxin, of which over 100 have been associated with
human disease. Two major Shiga toxin types (Stx1 and Stx2) have
been associated with strains causing human disease. While the
serotype O157:H7 is considered as clinically the most important, it is
estimated that up to 50% of STEC infections are caused by nonO157
serotypes. STEC is of public health concern because of the
potential for outbreaks and the risk of serious complications.
Haemolytic uremic syndrome (HUS) is considered as the most
common cause of acute renal failure in European children. Even if
the clinical presentation of non-O157 STEC infections may vary,
they can be as virulent as O157:H7 infections.
Shiga toxin-producing E. coli (STEC)
Transmission of STEC infection mainly occurs through
contaminated food or water and contact with animals.
Person-to-person transmission is also possible among
close contacts (families, childcare centres, nursing
homes, etc). A wide variety of food has previously been
implicated in outbreaks as suspected sources, including
raw (unpasteurised) raw milk and cheese, undercooked
beef, a variety of fresh produce (e.g. sprouts, spinach,
lettuce), unpasteurised apple cider, etc. Recently an
outbreak of STEC O157 infections in Canada and the
USA was linked to walnuts, thus new sources continue
to be identified. Various types of animals, in particular
cattle and other ruminants, can be healthy carriers of
human-pathogenic STEC that can be spread to humans
through faecal contamination.
Escherichia coli (E.coli)
Shiga toxin-producing E. coli (STEC)
• Shiga toxin-producing E. coli (STEC) is a group of pathogenic Escherichia coli strains
capable of producing Shiga toxins, with the potential to cause severe enteric and
systemic disease in humans. The full serotype is usually defined by determining both
O and H antigens. There are around 200 different E. coli O serotypes producing
Shiga toxin, of which over 100 have been associated with human disease. Two major
Shiga toxin types (Stx1 and Stx2) have been associated with strains causing human
disease. While the serotype O157:H7 is considered as clinically the most important, it
is estimated that up to 50% of STEC infections are caused by non-O157 serotypes.
STEC is of public health concern because of the potential for outbreaks and the risk
of serious complications. Haemolytic uremic syndrome (HUS) is considered as the
most common cause of acute renal failure in European children. Even if the clinical
presentation of non-O157 STEC infections may vary, they can be as virulent as
O157:H7 infections.
• Transmission of STEC infection mainly occurs through contaminated food or
water and contact with animals. Person-to-person transmission is also possible
among close contacts (families, childcare centres, nursing homes, etc). A wide
variety of food has previously been implicated in outbreaks as suspected sources,
including raw (unpasteurised) raw milk and cheese, undercooked beef, a variety of
fresh produce (e.g. sprouts, spinach, lettuce), unpasteurised apple cider, etc.
Recently an outbreak of STEC O157 infections in Canada and the USA was linked to
walnuts, thus new sources continue to be identified. Various types of animals, in
particular cattle and other ruminants, can be healthy carriers of human-pathogenic
STEC that can be spread to humans through faecal contamination.
Escherichia coli (E.coli)
The infective dose is very low. The incubation period ranges from three to eight
days. The typical presentation of infections with STEC is acute
gastroenteritis, often accompanied with mild fever and sometimes vomiting.
The typically bloody diarrhoea is in most cases mild and self-limiting and
most people recover within five to seven days. Around 15% of children
diagnosed with STEC O157 infection develop the severe complication of
HUS; this proportion is much lower among adults, and this proportion in
outbreaks of non-O157 outbreaks is not well documented. The severity of
STEC diarrhoea is determined by several factors, including the E. coli
serotype, the type of Shiga toxin produced and other virulence
characteristics of the bacteria. The patient’s age and the infecting dose also
play an important role. Children under the age of 5 years are at higher risk of
developing clinical disease when infected, and infants are at increased risk
of death from dehydration and septicaemia.
• While the confirmation methods of O157 STEC infection are well
established, this is not always the case for infections caused by STEC nonO157
serotypes. Therefore, underreporting of non-O157 STEC infections is
very likely, and their importance for clinical disease in humans is
insufficiently understood.
Escherichia coli (E.coli)
The treatment of STEC infections is mainly based on rehydration,
while antibiotic treatment is often contraindicated as it may
activate Shiga toxin release and therefore cause clinical
deterioration with a potential evolution to HUS.
• STEC infections in humans are under epidemiological
surveillance in the EU and in 2009 there were 3 573 reported
cases of which about half were caused by the STEC O157:H7
serotype.
• Since 2008, eight cases of STEC O104 have been reported in
the EU, by Austria (one case in 2010), Belgium (two cases in
2008), Denmark (one case in 2008), Norway (three cases in
2009), and Sweden (one case in 2010); three of these cases
were imported. In addition, between 2004 and 2009, Austria
and Germany reported some positive findings of STEC O104 in
food or animals. However, the suggested outbreak strain of
serotype STEC 0104:H4 has been rarely reported worldwide.
Shiga toxin-producing E. coli (STEC)
• While the confirmation methods of O157 STEC infection are well
established, this is not always the case for infections caused by
STEC non-O157 serotypes. Therefore, underreporting of non-O157
STEC infections is very likely, and their importance for clinical
disease in humans is insufficiently understood.
• The treatment of STEC infections is mainly based on rehydration,
while antibiotic treatment is often contraindicated as it may activate
Shiga toxin release and therefore cause clinical deterioration with a
potential evolution to HUS.
• STEC infections in humans are under epidemiological surveillance
in the EU and in 2009 there were 3 573 reported cases of which
about half were caused by the STEC O157:H7 serotype.
Prevention measures
All humans and animals carry the bacteria called
Escherichia coli (E. coli) in their intestines – they are part
of our normal flora and usually harmless. However, there
are particular strains of E. coli that are capable of
producing toxins. These strains are called STEC/VTEC
(shiga toxin or verotoxin –producing E. coli) or EHEC
(enterohaemorrhagic E. coli), and their toxins have the
potential to cause severe, bloody diarrhoea, which may
in some cases result in an acute kidney failure requiring
intensive care. There are several different strains of
STEC and their identification can be used to more
precisely find the source of a particular outbreak.
Prevention measures
Transmission of STEC infection mainly occurs through
eating or handling contaminated food and contact with
infected animals. Further person-to-person transmission
is possible among close contacts (families, childcare
centres, nursing homes, etc). A wide variety of food has
previously been implicated in outbreaks as sources of
infection, including undercooked beef and other meat,
unpasteurized milk, a variety of fresh produce (e.g.
cucumber, sprouts, spinach, and lettuce), unpasteurized
apple juice and cheese. A very small number of STEC
bacteria are sufficient to cause infection in humans.
Good personal hand hygiene
• Wash your hands properly with soap, rinse carefully and
dry using disposable kitchen towel or a textile towel (to
be washed regularly at 60°C):
• before preparing, serving, or eating food
• after using the toilet or changing nappies (diapers)
• after handling raw vegetables, roots or meat
• after contact with farm animals or after visiting a farm
• after any contact with faeces from household pets
Food handling
• Any person with diarrhoea or vomiting should restrain from handling
food
• Meat, including minced meat, should be thoroughly cooked
• All fruits with skin should be peeled and then rinsed under running
potable water
• All vegetables should be washed properly under running potable
water, especially those that will not be cooked before consumption
• Peel all root vegetables and rinse them under running potable water
• Thorough cooking of vegetables and meat destroys disease causing
bacteria and viruses
• Avoid cross contamination i.e. spreading bacteria from a raw food
item to a ready-to-eat or cooked food item, by for example, using
separate cutting boards for raw meat and cooked meat or fresh
vegetables and wash the cutting board with soap in between the
handling of raw and ready-to-eat food.
Giardiasis
Giardia lamblia (Giardia intestinalis and Giardia
duodenalis are synonyms) is a cyst-producing
parasite, able to settle in the human and animal bowel.
The parasites could cause disease equally in humans
and animals such as dogs, cats, cows and sheep. In
the environment, major reservoirs of the parasite are
contaminated surface waters.
GIARDIASIS (Giardia lamblia) – Case definition
Clinical Criteria
• Any person with at least one of the following
four:
• — Diarrhoea
• — Abdominal pain
• — Bloating
• — Signs of malabsorption (e.g.
steatorrhoea, weight loss)
Laboratory Criteria
• At least one of the following two:
• — Demonstration of Giardia lamblia cysts or
trophozoites in stool, duodenal fluid or smallbowel
biopsy
• — Demonstration of Giardia lamblia antigen
in stool
Epidemiological Criteria
• At least one of the following four
epidemiological links:
• — Exposure to contaminated food/drinking
water
• — Human to human transmission
• — Exposure to a common source
• — Environmental exposure
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and
with an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Giardiasis
Symptoms
People who have swallowed Giardia cysts sometimes have no
symptoms; this is particularly common in children. For those
who have symptoms, the most common are diarrhoea, malaise,
flatulence, foul-smelling and greasy stools, abdominal cramps,
bloating, nausea, loss of appetite and weight loss. Prolonged
diarrhoea, weight loss and not absorbing nutrients from food
passing through the intestines are particular symptoms of
giardiasis.
• Complications
Symptoms can occasionally be very severe, especially in young
children or pregnant women. Symptoms can be acute,
chronic—lasting some time—or relapsing, clearing up and then
recurring.
Giardiasis
Ways to catch giardiasis
Giardiasis is caught by swallowing parasites or their cysts from
infected faeces, either directly or through contaminated food or
water. Consumption of contaminated recreational or drinking
water appears to be the most common source. Direct personto-person
transmission, again through contact with infected
faeces, is the other main source of infection. Foodborne
outbreaks have happened, usually linked to infected food
handlers or their contacts.
• People most at risk
Most cases happen in children aged 0–4, followed by those
aged 5–14 and then adults aged 25–44. Cases happen
throughout the year, with slight peaks in spring and autumn.
Higher rates of infection are seen in refugees, people living in
institutions, travellers abroad, gay men and people whose
immune systems are compromised.
Giardiasis
Diagnosis
Giardiasis can be diagnosed by looking at samples
from stools under a microscope and by other
laboratory tests.
• Treatment
Antimicrobial treatment is available for giardiasis.
Giardiasis
How to avoid getting giardiasis
Normal water treatment processes should be effective
in removing Giardia cysts from drinking water. Good
personal and food hygiene, especially hand washing,
are important in preventing the spread of giardiasis,
especially in institutions like nurseries or care homes.
There is no vaccine to protect humans against
giardiasis, although a vaccine may be available for
pets.
• What to do if you have giardiasis
Food handlers, healthcare workers and affected
nursery children should stay at home until 48 hours
after their symptoms have ceased in order to avoid
spreading the infection.
Leptospirosis
Leptospirosis is a zoonotic disease caused by Leptospira bacteria. Although more
common in tropical areas of the world, the disease is also present in temperate
areas, including Europe. Different species of domestic and wild animals act as
maintenance hosts. Humans acquire leptospirosis either from direct contact with the
urine of infected animals, or from contact with material contaminated by it, such as
water or soil. After exposure, the incubation period ranges between two and 30 days
(with an average of 10 days). The clinical presentation is variable. Fever, muscle
ache and eye infection are very frequent. Liver, kidney, lung, heart, and more rarely
brain involvement and bleeding characterise the most serious clinical presentations.
Timely antibiotic treatment is effective, and the death rate is low, but does increase
with advancing age and may reach up to 20% or more in complicated cases with
severe disease.
• Preventive measures include controlling rodent populations, avoiding contaminated
areas and covering cuts and abraded skin when operating in the environment.
Immunisation of persons at occupational risk of exposure has been carried out in
some countries (Italy, France, Spain).
•
LEPTOSPIROSIS (Leptospira spp.) – Case definition
Clinical Criteria
• Any person with
• — Fever
• OR
• At least two of the following eleven:
• — Chills
• — Headache
• — Myalgia
• — Conjunctival suffusion
• — Haemorrhages into skin and mucous membranes
• — Rash
• — Jaundice
• — Myocarditis
• — Meningitis
• — Renal impairment
• — Respiratory symptoms such as haemoptysis
Laboratory Criteria
• At least one of the following four:
• — Isolation of Leptospira interrogans or any other pathogenic
Leptospira spp. from a clinical specimen
• — Detection of Leptospira interrogans or any other pathogenic
Leptospira spp. nucleic acid in a clinical specimen
• — Demonstration of Leptospira interrogans or any other pathogenic
Leptospira spp. by immunofluorescence in a clinical specimen
• — Leptospira interrogans or any other pathogenic Leptospira spp.
specific antibody response
Epidemiological Criteria
• At least one of the following three epidemiological links:
• — Animal to human transmission
• — Environmental exposure
• — Exposure to a common source
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria and with an
epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the laboratory
criteria
Leptospirosis
• NAME AND NATURE OF INFECTING ORGANISM Leptospirosis is a
zoonosis occurring worldwide, caused by pathogenic spirochaetes of the
genus Leptospira. Pathogenic leptospires live in the kidneys of a large
variety of mammalian species and are excreted into the environment with
the urine. Indirect infection through contact with leptospires secreted into the
environment is probably the main route of acquiring leptospirosis.
Pathogenic leptospires survive longer in a warm and humid environment.
Therefore, the disease is particularly prevalent in wet tropical and
subtropical regions. The bacterium is sensitive to dry conditions, extreme
temperatures and detergents. Currently nearly 300 serovars have been
identified, divided into 25 serogroups. Seven main pathogenic species are
known.
• Leptospirosis is the most widespread and most prevalent zoonotic disease.
The disease is (re-) emerging globally and numerous outbreaks have
occurred worldwide during the past decade. In Europe, leptospirosis occurs
mainly in the Mediterranean and East European regions.
Leptospirosis
• 2. CLINICAL FEATURES
• The incubation period varies from 2 to 30 days, with an average
of 7–10 days. Leptospirosis varies from mild to severe clinical
presentation, and may cause potentially fatal conditions such
as Weil’s syndrome and the emerging Severe Pulmonary
Haemorrhagic Syndrome (SPHS). Generally, leptospirosis is an
acute biphasic illness: the first phase (4–9 days) presents with
an abrupt onset of a flu-like illness, with a severe headache,
chills, muscle aches, and vomiting, while in the second phase
the patient develops fever, jaundice, abdominal pain and
diarrhoea. In severe cases there may be organ failure. If
untreated, recovery may take several months.
Leptospirosis
• 3. TRANSMISSION
• 3.1 Reservoir
• About 160 mammalian species have been identified as natural carriers of pathogenic
leptospires. These include feral, semi-domestic and farm and pet animals as
important infection sources. The infectious period of natural hosts can be lifelong.
Accidental hosts can act as intermediate infection source, and may shed leptospires
for days or months.
• 3.2 Transmission mode
• The route of transmission is via broken skin and through mucous membranes of
eyes, mouth and nose (consumption, inhalation). Transmission through waterweakened
skin is controversial. Transmission may also occur via sexual contact and
mother’s milk. In-uterus transmission can lead to reproductive failures such as
abortion.
• 3.3 Risk groups
• The risk of acquiring leptospirosis is associated with contact with animals and thus
with occupations such as farmers, veterinarians and sewer workers. Case severity is
associated with physical condition and increasing age. Leptospirosis as a
recreational disease in travellers is increasing in Western countries.
Leptospirosis
• . PREVENTION MEASURES
• Prevention and control mainly focus on the identification and reduction
of the infection source and the prevention of penetration of leptospires
into the accidental host. Prevention of transmission can be achieved
by wearing protective clothing. Prophylactic treatment with
doxycycline is protective to some extent. Vaccination is available in a
limited number of countries, but currently not considered as a
generally applicable option.
• Improving water and food storage conditions, increasing public
awareness about the disease and infection risks, as well as the control
of rodents, may reduce the risk of transmission. Infection risk from
domestic animals can be reduced by vaccination or treatment of
carriers. Both approaches should be combined with herd management.
Vaccines are available for cattle, dogs and pigs, and provide a shortterm
serovar-specific protection.
Leptospirosis
• 5. DIAGNOSIS
• The confirmation of a clinically suspected leptospirosis case is usually
done through culturing and the Microscopic Agglutination Test (MAT);
both are quite laborious and require well-equipped laboratories with
experienced staff. Several rapid tests for humans are currently
available, mainly for screening purposes, and results must be
confirmed by standard tests.
• 6. MANAGEMENT AND TREATMENT
• Early diagnosis is critical in the treatment of patients with
leptospirosis. In severe cases, high doses of intravenous penicillin are
recommended, but Jarish-Herxheimer reactions may occur. In less
severe cases, oral antibiotics such as amoxycillin, ampicillin,
doxycycline or erythromycin are administered. Third generation
cephalosporins and quinolone antibiotics also seem to be effective.
Listeriosis
• Listeriosis is a disease caused by Listeria monocytogenes. The disease primarily
causes problems in pregnant women, newborns, and adults with a weakened
immune system. Listeria bacteria are ubiquitous in the environment, and food-borne
outbreaks have been detected worldwide. Many animals carry the bacteria in their
faeces.
• After exposure (via contaminated food) most healthy adults do not develop any
symptoms, except in the case of pregnant women. After an incubation period of
about three weeks pregnant women may suffer from a self-limiting influenza-like
illness which may affect the uterus. In that case, it can lead to death of the foetus and
consequent abortion or to a dramatic picture of congenital listeriosis in the newborn.
In addition, listeriosis in adults with weakened immune system and the elderly may
lead to meningitis, brain infection, and severe blood infection. All clinical
presentations are treatable with prolonged courses of antibiotics, but the prognosis of
the most serious ones is poor.
• Control measures should be aimed at the farm and food-processing level, in order to
prevent contamination of food products. Preventive measures include providing
appropriate information for consumers on how to minimise the risk of ingesting food
contaminated by Listeria.
•
Listeriosis
• Symptoms
Listeriosis can cause a range of symptoms. Some patients can have no
symptoms at all. Previously well, non-pregnant people often get symptoms
of acute gastroenteritis—inflammation of the stomach and intestines. This
can cause headache, fever, abdominal pain, sleepiness, nausea and
diarrhoea. Fatigue, aching muscles, painful joints, vomiting and a sore throat
may also occur.
• Complications
Listeriosis can also cause serious illness, most often in those with long-term
health conditions, the elderly, or people whose immune systems are
compromised. Severe symptoms can include the following: blood poisoning;
inflammation of the brain and its lining; abscesses; inflammation of the lining
of the heart; and infected or inflamed joints. Pregnant women who get the
infection may only have mild illness, but can suffer miscarriage, premature
delivery or stillbirth. Newborn babies can also suffer from severe symptoms,
including meningitis, which can lead to death.
Listeriosis
• Ways to catch listeriosis
The bacteria that cause listeriosis are widespread in the environment
and can be found in soil, surface water, vegetation and a range of wild
and domestic animals. Most humans catch the infection by eating
contaminated food. The bacteria can grow at low temperatures and are
tolerant of salt and therefore can survive in processed, preserved and
refrigerated foods. Foods that have been associated with spreading
listeriosis include the following: processed meat and fish, cold meats
and hot dogs; dairy products, such as soft cheese, butter and milk,
especially if unpasteurised; and pre-prepared salads, sandwiches and
salads. Other sources of infection include direct contact from animals
or the environment. Pregnant women can pass the infection to their
babies during birth or through the placenta.
• People most at risk
Reported cases in Europe are highest among those over 65 and
children younger than four.
Listeriosis
• Diagnosis
Laboratory tests are carried out on samples of
blood or cerebrospinal fluid to diagnose the
infection. Laboratory tests are also carried out on
food and environmental samples to look for
Listeria.
• Treatment
Antibiotics can be used to treat patients.
Listeriosis
• How to avoid getting listeriosis
Pasteurising dairy products is important as the process
kills Listeria. Cook-chill and ready-to-eat foods should not
be stored for too long and should be thoroughly reheated
before serving. Raw vegetables, fruits and salads should
be thoroughly washed before eating. Pregnant women and
people whose immune systems are compromised are
advised to avoid soft cheeses, pâté and pre-packed salads,
contact with pregnant or newborn animals and silage.
Hand washing is effective at reducing the risk of
gastroenteritis from many organisms and may be made
even more effective by using antibacterial soap. There is
no vaccine against listeriosis.
Shigellosis
SHIGELLOSIS (Shigella spp.) – Case definition
Clinical Criteria
• Any person with at least one of the following four:
• — Diarrhoea
• — Fever
• — Vomiting
• — Abdominal pain
Laboratory Criteria
• — Isolation of Shigella spp. from a clinical
specimen
Epidemiological Criteria
• At least one of the following five epidemiological
links:
• — Human to human transmission
• — Exposure to a common source
• — Animal to human transmission
• — Exposure to contaminated food/drinking water
• — Environmental exposure
Case Classification
• A. Possible case NA
• B. Probable case
• Any person meeting the clinical criteria
and with an epidemiological link
• C. Confirmed case
• Any person meeting the clinical and the
laboratory criteria
Toxoplasmosis (congenital)
TOXOPLASMOSIS, CONGENITAL (Toxoplasma gondii) - Case definition
Clinical Criteria
• Not relevant for surveillance purposes
Laboratory Criteria
• At least one of the following four:
• — Demonstration of Toxoplasma gondii in body tissues or fluids
• — Detection of Toxoplasma gondii nucleic acid in a clinical specimen
• — Toxoplasma gondii specific antibody response (IgM, IgG, IgA) in a newborn
• — Persistently stable IgG Toxoplasma gondii titres in an infant (< 12 months of age)
Epidemiological Criteria NA
Case Classification
• A. Possible case NA
• B. Probable case NA
• C. Confirmed case
• Any infant meeting the laboratory criteria
Toxoplasmosis (congenital)
Toxoplasmosis (congenital)
Norovirus infection
• Norovirus cause gastrointestinal illness to humans. Norovirus
infection can cause vomiting, diarrhoea, and stomach pain. Less
common symptoms are low fever, chills and headache. Vomiting
can be sudden and frequent resulting in remarkable fluid loss. Death
is rare but remains as a risk especially for elderly or persons with
weakened immune system.
Recovery occurs usually in one or two days. The incubation period
ranges between 12 and 48 hours. Sometimes, symptoms can be
milder and last for a week but no long-term adverse health effects
have been reported.
•
Norovirus infection
• Noroviruses belong to the Caliciviridae family and they
are well known as causing “winter-vomiting disease” or
“stomach-flu” referring to their rapid spread in human
populations especially during winter months. Noroviruses
are relatively resistant in the environment: they can
survive freezing as well as high temperatures (up to
60°C). The viruses survive long periods on different
surfaces. Steam cooking of shellfish may allow them to
survive. It is important to notice that the viruses can
survive in up to 10 ppm chlorine, well in excess of levels
routinely present in public drinking water systems (less
that 2 ppm).
Norovirus infection
• Noroviruses are highly contagious and 10-100 viral particles may be
sufficient to infect an individual. They are transmitted primarily
through the faecal-oral route, either by consumption of contaminated
food or water, or by spreading directly from person to person.
Vomiting creates effectively aerosols with high content of virus
particles, which enter the oral mucosa or contaminate surfaces. The
virus survives long on different surfaces and thus, environment may
serve as a source of new infections. During one single outbreak of
norovirus gastroenteritis, several modes of transmission usually
occur. Even though the incubation period is relatively short (15-50
h), since the infective dose is very small, and asympomatic shedding
does occur, the origin of the outbreak is often difficult to confirm. For
example, initially food or water borne transmission is often followed
by secondary person-to-person transmissions to close contacts.
Virus shedding usually starts with the onset of symptoms (mainly
vomiting and diarrhea) and may continue for 2 weeks after
recovery.
Norovirus infection
• As the immunity may only last a few months and is strain-specific,
and given their genetic variability, infection can happen several
times in a lifetime and affects individuals of all ages.
Susceptibility to infection is probably genetically determined.
According to recent studies, persons of blood group 0 are at
greatest risk for infection.
Many different food items have been associated with norovirus
outbreaks. Raspberries and oysters have caused several national
and international outbreaks. In principle, any food item may become
contaminated if handled by infected person or if washed or
humidified with contaminated water. Norovirus infections spread
effectively from person to person in community settings like
hospitals, schools, day care centers and nursing homes. Several
outbreaks have been recorded in cruise ships, which provide an
ideal closed setting for the spread of infection.