Enteric Infections and Food Poisoning Overview
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Questions and Answers

What is the primary cause of gastroenteritis?

  • Contaminated food
  • Irritating food or drink
  • Psychological factors such as stress
  • All of the above (correct)

    • Which of the following is NOT a common symptom of food poisoning?

  • Liver failure (correct)
  • Gastroenteritis
  • Systemic illness
  • Neurological syndromes

    • Which of the following food items is specifically mentioned as a potential source of food poisoning?

  • Shellfish (correct)
  • Vegetables
  • Grains
  • Fruits

    • What is the minimum number of loose stool episodes in a 24-hour period to define diarrhea?

    <p>3 episodes</p> Signup and view all the answers

    Which virulence factor contributes to the pathogenesis of foodborne pathogens?

    <p>Capsule production</p> Signup and view all the answers

    What method is often used for the laboratory diagnosis of food poisoning?

    <p>Stool culture</p> Signup and view all the answers

    Which of the following is NOT a recommended measure to prevent foodborne illnesses?

    <p>Consuming raw shellfish</p> Signup and view all the answers

    What is the main route of transmission for foodborne pathogens?

    <p>Faecal-oral route</p> Signup and view all the answers

    Which diagnostic method is used to confirm a diagnosis of COLI?

    <p>Stool PCR</p> Signup and view all the answers

    What is the main characteristic of the diarrhoea caused by enterotoxigenic E. coli?

    <p>Watery diarrhoea without blood</p> Signup and view all the answers

    What are the possible outcomes for infants affected by enteropathogenic E. coli?

    <p>Severe dehydration and higher mortality</p> Signup and view all the answers

    Which of the following statements about listeria monocytogenes is correct?

    <p>It can grow at temperatures as low as 2°C.</p> Signup and view all the answers

    What management strategy is recommended for treating COLI?

    <p>Rehydration is the primary treatment.</p> Signup and view all the answers

    What is the primary source of Campylobacter spp. infections in humans?

    <p>Contaminated animal products</p> Signup and view all the answers

    What is the main clinical feature of a Campylobacter infection?

    <p>Severe abdominal pain</p> Signup and view all the answers

    Which condition is a rare complication of Campylobacter infections?

    <p>Guillain-Barre syndrome</p> Signup and view all the answers

    What is the incubation period for Campylobacter infections?

    <p>2-4 days</p> Signup and view all the answers

    Which laboratory finding is characteristic of Campylobacter spp.?

    <p>Curved-shaped, Gram-negative bacilli</p> Signup and view all the answers

    How does Campylobacter typically spread in humans?

    <p>Foodborne transmission</p> Signup and view all the answers

    Which symptom can indicate a severe case of Campylobacter infection?

    <p>Bloody diarrhea</p> Signup and view all the answers

    What pathophysiological mechanism does Campylobacter employ to damage the intestine?

    <p>Adheres and invades mucosal surfaces</p> Signup and view all the answers

    What is the primary characteristic of the toxin produced by Staphylococcus aureus?

    <p>It is a heat-stable enterotoxin that can cause rapid onset symptoms.</p> Signup and view all the answers

    What conditions are most conducive to the growth of Staphylococcus aureus in food?

    <p>Food left at room temperature after being handled.</p> Signup and view all the answers

    Which type of food is primarily associated with Bacillus cereus Type 1 Emetic Syndrome?

    <p>Cooked rice that has cooled slowly.</p> Signup and view all the answers

    What symptom is most commonly associated with Clostridium perfringens infections?

    <p>Profuse diarrhoea.</p> Signup and view all the answers

    What is the recommended incubation period for Clostridium perfringens to cause symptoms?

    <p>8-24 hours.</p> Signup and view all the answers

    Which of the following incorrectly describes the Clostridium botulinum toxin?

    <p>It is a heat-stable toxin that cannot be inactivated by cooking.</p> Signup and view all the answers

    What is the primary treatment approach for foodborne illnesses caused by these toxins?

    <p>Providing supportive care.</p> Signup and view all the answers

    Which of the following practices can help prevent foodborne illnesses from bacterial toxins?

    <p>Keeping cooked and raw food separate.</p> Signup and view all the answers

    What is a significant characteristic of Listeria monocytogenes regarding its survival in the body?

    <p>It survives within macrophages.</p> Signup and view all the answers

    Which group is most at risk for severe illness from Listeria monocytogenes?

    <p>Immunosuppressed patients and pregnant women.</p> Signup and view all the answers

    What is a common clinical feature of neonatal listeriosis?

    <p>CNS involvement and abscesses.</p> Signup and view all the answers

    What complication may occur in pregnant women due to Listeria monocytogenes?

    <p>Miscarriage and intrauterine death.</p> Signup and view all the answers

    How is Listeria monocytogenes typically diagnosed in a patient?

    <p>Blood cultures or CSF analysis.</p> Signup and view all the answers

    What treatment is commonly used for Listeria monocytogenes infections?

    <p>High dose ampicillin with aminoglycoside.</p> Signup and view all the answers

    What preventive measure is recommended for people at high risk of Listeria monocytogenes infection?

    <p>Steer clear of raw or partially cooked animal products.</p> Signup and view all the answers

    Which of the following is a recognized characteristic of late onset neonatal listeriosis compared to early onset?

    <p>More common than early onset.</p> Signup and view all the answers

    What is the primary characteristic of enterotoxigenic E. coli in terms of its biological behavior?

    <p>It adheres to the intestinal lining without invasiveness.</p> Signup and view all the answers

    During which environmental condition is Listeria monocytogenes most likely to peak in infection rates?

    <p>Warmer months when foodborne pathogens thrive.</p> Signup and view all the answers

    What symptom differentiates enteropathogenic E. coli from enterotoxigenic E. coli?

    <p>Major loss of villi leading to malabsorption.</p> Signup and view all the answers

    What is the recommended isolation protocol for managing COLI?

    <p>Isolation in hospital requiring contact precautions.</p> Signup and view all the answers

    Which type of toxin produced by enterotoxigenic E. coli is associated with increased electrolyte secretion leading to diarrhea?

    <p>LT (heat-labile) toxin causing short-term fluid loss.</p> Signup and view all the answers

    Which of the following types of illnesses can result from food poisoning?

    <p>Systemic illnesses like listeriosis and enteric fever</p> Signup and view all the answers

    What is the primary cause of food poisoning caused by bacteria?

    <p>Ingestion of food containing bacteria or their toxins</p> Signup and view all the answers

    Which of the following factors can contribute to the occurrence of foodborne infections?

    <p>Lack of hygiene in food handling</p> Signup and view all the answers

    Which of the following correctly describes the phenomenon of gastroenteritis?

    <p>Acute inflammation of the stomach and intestines from various causes</p> Signup and view all the answers

    What is the primary mechanism by which the toxin from Campylobacter spp. affects the human body?

    <p>Binds to presynaptic nerve endings</p> Signup and view all the answers

    Which pathogen is NOT typically associated with food poisoning?

    <p>Mycobacterium tuberculosis</p> Signup and view all the answers

    Which of the following is a significant complication associated with Campylobacter infection?

    <p>Toxic megacolon</p> Signup and view all the answers

    In the context of food poisoning, what does the term 'faecal-oral route' refer to?

    <p>Ingestion of water contaminated by human waste</p> Signup and view all the answers

    What prevention method is crucial for reducing the spread of foodborne illnesses?

    <p>Ensuring proper hand hygiene among food workers</p> Signup and view all the answers

    Which of the following species is most commonly associated with human disease caused by Campylobacter?

    <p>C. jejuni</p> Signup and view all the answers

    What is the typical laboratory diagnosis feature of Campylobacter spp. on selective charcoal media?

    <p>Curved-shaped greyish colonies</p> Signup and view all the answers

    Which of the following is a common consequence of food poisoning that can occur after initial symptoms?

    <p>Progression to systemic illnesses such as listeriosis</p> Signup and view all the answers

    During what seasonal period do cases of Campylobacter infection tend to peak, and why?

    <p>Summer, due to barbecue season</p> Signup and view all the answers

    What typically follows the incubation period of 2-4 days in a Campylobacter infection?

    <p>Manifestation of prodromal symptoms</p> Signup and view all the answers

    Which of the following transmission routes for Campylobacter is least common?

    <p>Spread through aerosols from infected animals</p> Signup and view all the answers

    In severe cases of Campylobacter infection, what pathological finding may occur in the bowel?

    <p>Crypt abscess formation</p> Signup and view all the answers

    What is the primary rapid effect of the Staphylococcus aureus enterotoxin after ingestion?

    <p>Predominantly vomiting</p> Signup and view all the answers

    What type of food is primarily associated with Bacillus cereus Type 2 Diarrhoeal Syndrome?

    <p>Meats and salads</p> Signup and view all the answers

    Which of the following correctly describes the incubation period for Clostridium perfringens infections?

    <p>8-24 hours</p> Signup and view all the answers

    What symptoms primarily characterize an outbreak of Clostridium perfringens food poisoning?

    <p>Profuse diarrhea and occasional vomiting</p> Signup and view all the answers

    What is the most critical factor contributing to the growth of Staphylococcus aureus in food?

    <p>Poor refrigeration and room temperature storage</p> Signup and view all the answers

    What aspect of Clostridium botulinum toxin is particularly concerning in food safety?

    <p>It is a neurotoxin that can lead to severe neurological symptoms</p> Signup and view all the answers

    Which food safety practice is crucial for preventing the growth of Bacillus cereus?

    <p>Cooling food immediately after cooking</p> Signup and view all the answers

    What factor does NOT contribute to the severity of foodborne illnesses caused by bacterial toxins?

    <p>The color of the contaminated food</p> Signup and view all the answers

    What is the primary reservoir of enterohaemorrhagic E. coli?

    <p>Cattle</p> Signup and view all the answers

    Which serotype is most commonly associated with enterohaemorrhagic E. coli infections?

    <p>E.coli O157:H7</p> Signup and view all the answers

    Which clinical feature indicates a severe case of enterohaemorrhagic E. coli infection, especially in infants?

    <p>Bloody diarrhoea</p> Signup and view all the answers

    Which of the following antibiotics is recommended for use in cases of enterohaemorrhagic E. coli infection?

    <p>Ciprofloxacin</p> Signup and view all the answers

    What complication occurs in approximately 10% of children under 10 years of age infected with enterohaemorrhagic E. coli?

    <p>Hemolytic uremic syndrome</p> Signup and view all the answers

    Which of the following practices can help prevent infections caused by enterohaemorrhagic E. coli?

    <p>Washing hands after contact with animals</p> Signup and view all the answers

    What pathophysiological mechanism does enterohaemorrhagic E. coli primarily use to harm the intestinal lining?

    <p>Disrupting protein synthesis</p> Signup and view all the answers

    What is the typical incubation period for infections caused by enterohaemorrhagic E. coli?

    <p>1-10 days</p> Signup and view all the answers

    Study Notes

    Enteric (GI) Infections

    • Gastroenteritis: inflammation of the stomach and intestines, can be caused by food poisoning, irritants, or stress.
    • Food poisoning: illness caused by consuming contaminated food containing microorganisms, toxins, or poisons.
    • Diarrhoea: 3 or more episodes of loose or liquid stool in a 24-hour period.

    Food Poisoning Epidemiology

    • Common and multi-factorial: with many infectious causes.
    • Sporadic and outbreak potential: often affecting individuals but can cause large outbreaks.
    • Notifiable to Public Health: reported to authorities (full list on HPSC website).
    • Transmission: mainly contaminated food or water, via faecal-oral route.

    Infectious Causes of Food Poisoning

    • Bacterial: Staphylococcus aureus, Clostridium spp, Campylobacter spp.
    • Viral: Refer to viral gastroenteritis lectures.

    Staphylococcus aureus (S. aureus)

    • Heat-stable enterotoxin: ingested through contaminated food.
    • Food sources: dairy, produce, meats, eggs, salads.
    • Contamination process: food handler contaminates food, left at room temperature, organisms multiply producing toxin.
    • Symptoms: vomiting (predominant), occasionally diarrhoea.
    • Duration: 1-8 hours of incubation, lasting 8-24 hours.
    • Outbreak prevalence: common during summer months.
    • Diagnosis: based on history.
    • Treatment: supportive care.

    Bacillus Cereus (B. cereus)

    • Two forms of poisoning: emetic syndrome and diarrhoeal syndrome.
    • Emetic Syndrome: Ingestion of preformed toxin, usually through cooked rice allowed to cool slowly at room temperature.
    • Diarrhoeal Syndrome: Ingestion of spores in foods like meats, salads, chicken soup.
    • Emetic Syndrome symptoms: vomiting, abdominal cramps, may have diarrhoea, lasts 2-10 hours.
    • Diarrhoeal Syndrome symptoms: diarrhoea (main symptom), lasts 8-24 hours.
    • Duration: 1-6 hours (emetic) and 6-14 hours (diarrhoeal).
    • Diagnosis: based on history.
    • Treatment: supportive care.

    Clostridium perfringens (C. perfringens)

    • Spore contamination: food contaminated with heat- resistant spores are ingested.
    • Food sources: Incorrectly stored cooked meat dishes, gravy, dairy products.
    • Toxin production: Multiplication in the small intestine, sporulation and enterotoxin production.
    • Incubation period: 8-24 hours.
    • Symptoms: profuse diarrhoea, occasionally vomiting.
    • Duration: 1-3 days.

    Clostridium botulinum (C. botulinum)

    • Toxin (neurotoxin) ingestion: food contaminated with toxin is ingested.
    • Food sources: improperly canned products, home bottled items (e.g. pickles, honey).
    • Incubation period: 12-36 hours.
    • Toxin action: absorbed from GIT into bloodstream, binds to nerve endings, inhibits acetylcholine release.
    • Symptoms: acute descending symmetrical weakness, bilateral cranial nerve palsies, paralysis, requiring mechanical ventilation.
    • Mortality rate: 20%.
    • Treatment: anti-toxin.

    Campylobacter spp

    • Most common cause of bacterial food poisoning: in developed countries.
    • Species causing disease: C. jejuni (most common), C. coli, C. fetus, C. lari.
    • Source: Normal flora in animals, particularly cattle, swine, and birds.
    • Zoonosis: transmission from animals to humans through contaminated animal products.
    • Contamination: Carcasses/meat contaminated by faeces during slaughter.
    • Routes of transmission: mainly foodborne (undercooked meat, raw or contaminated milk), less common person-person via faecal-oral route.
    • Peak season: summer months.

    Campylobacter spp. Pathogenesis

    • Ingestion: enters the body.
    • Adherence: adheres to jejunum and ileum.
    • Cytotoxin action: causes local damage (mucosal invasion), occasionally causing severe haemorrhagic necrosis of the small intestine.
    • Large bowel involvement: may involve large bowel with crypt abscess formation (severe cases), resembling ulcerative colitis.
    • Bloodstream spread: occurs in some individuals.

    Campylobacter spp. Clinical Features

    • Incubation period: 2-4 days (up to 8-9 days).
    • Symptoms: prodromal illness (fever, headache), diarrhoea (may be bloody), abdominal pain (can be severe).
    • Duration: resolves in 5-7 days.
    • Complications: Toxic megacolon, bacteraemia (extremes of age/immunosuppressed), Guillain-Barre syndrome (rare).

    Campylobacter spp. Laboratory Diagnosis

    • Microscopy: Gram-negative bacilli with typical curved shape.
    • Culture: greyish colonies on selective charcoal-containing media incubated in CO2 at 42°C.
    • Tests: positive oxidase test, hydrolyzes hippurate (blue colour).

    Campylobacter spp. Management

    • Rehydration: essential for managing dehydration.
    • Antibiotics not indicated: may increase toxin release, worsening symptoms.
    • Isolation: require isolation in hospital, contact precautions.

    Enterotoxigenic Escherichia coli (ETEC)

    • Travellers' diarrhoea: common in underdeveloped countries with poor sanitation.
    • Incubation period: 1-3 days.
    • Symptoms: watery (non-bloody) diarrhoea, fever, nausea, ranging from mild discomfort to severe cholera-like syndrome.
    • Duration: self-limiting, 1-5 days.
    • Infected site: small intestine.
    • Pathogenesis: adheres to intestinal mucosa without invasion, enterotoxins (LT and ST) cause fluid and electrolyte secretion, leading to diarrhoea.

    Enteropathogenic Escherichia coli (EPEC)

    • Major cause of infantile gastroenteritis: in infants younger than 6 months old, particularly in developing countries.
    • Mortality rate: high due to severe dehydration.
    • Transmission: person-to-person spread, potentially causing outbreaks.
    • Infected site: small intestine.
    • Pathogenesis: attaches to intestinal mucosa, causing loss of villi, invades host cells and disrupts cellular signal transduction, leading to symptoms.
    • Symptoms: watery diarrhoea, vomiting, fever.

    Listeria monocytogenes (L. monocytogenes)

    • Wide temperature tolerance: grows between 2-37°C.
    • Peak infection: warmer months.
    • Transmission: contaminated milk, certain soft cheeses, pate, animal contact, vertical transmission (mother to foetus).
    • Pathogenesis: crosses mucosal barrier and spreads, survives within macrophages, requiring a T-cell response for killing infected cells.

    Listeria monocytogenes Clinical Features

    • Healthy adults: mostly asymptomatic or mild influenza-like illness/diarrhoea.
    • Occupational risk: farmers, vets, butchers.
    • At-risk groups: pregnant women, neonates, immunosuppressed patients.
    • Complications: pneumonia, meningoencephalitis in immunosuppressed patients.

    Listeria monocytogenes & Pregnancy

    • Perinatal listeriosis: influenza-like illness in mother, usually in the third trimester.
    • Complications: miscarriage, intrauterine death, premature labour, neonatal listeriosis.
    • Neonatal listeriosis: early onset (first 2 days of life) acquired in utero, or late onset (after 5 days) acquired from maternal genital tract.
    • Early Onset symptoms: BSI, pneumonia, cardiopulmonary distress, hepatosplenomegaly, abscesses, CNS involvement.
    • Late Onset symptoms: meningitis, meningoencephalitis, BSI.

    Listeria monocytogenes Diagnosis and Treatment

    • Diagnosis: blood cultures, CSF, vaginal swab, placenta, microscopy (gram-positive bacillus with tumbling motility).
    • Treatment: high dose ampicillin/amoxicillin with an aminoglycoside (e.g. Gentamicin).
    • Resistant to cephalosporins.
    • Prevention: Avoid raw or partially cooked foods of animal origin for high-risk groups.

    Cryptosporidium

    • Species: C. parvum and C. hominis.
    • Clinical presentation: to be discussed further.

    Enteric (GI) Infections

    • Gastroenteritis - acute inflammation of stomach and intestines lining, caused by food poisoning, irritating food/drink, or psychological factors
    • Food Poisoning - illness from contaminated food or food that contains microorganisms/toxins/poisons
    • Diarrhea - 3+ episodes of loose/liquid stools within 24 hours

    Food Poisoning: Epidemiology

    • Common and caused by many infectious agents
    • Usually sporadic but can cause outbreaks
    • Notifiable to Public Health
    • Transmission: Contaminated food/water & Faecal-oral route

    Infectious Causes

    • Bacterial:
      • Staphylococcus aureus, Clostridium spp., Campylobacter spp.
    • Viral:
      • See lecture on viral gastroenteritis

    Toxins: S.aureus

    • Heat-stable enterotoxin ingested in food (dairy, produce, meats, eggs, salads)
    • Food handler contaminates food -> left at room temp -> organisms multiply -> produce toxin
    • Person ingests enteroxin
    • Works fast (1-8 hrs) -> vomiting predominates, occasional diarrhea
    • Lasts 8-24 hrs; outbreaks especially in summer
    • Diagnosis = History; Treatment = Supportive

    Toxins: Bacillus cereus

    • Type 1: Emetic syndrome:
      • Ingested in preformed toxin (cooked rice)
      • Allowed to cool slowly at room temp or held for long period
      • Germination from spores with release of toxin
      • Rapid heating doesn't destroy toxin
    • Type 2: Diarrhoeal syndrome:
      • Spores ingested in food (meats, salads, chicken soup)
      • Toxin production after spores germinate
      • Works fast (1-6 hours) -> Predominantly vomiting, abdominal cramps, may have diarrhea
      • Lasts 2-10 hours
      • Diagnosis = History; Treatment = Supportive

    Toxins: Clostridium perfringens

    • Food contaminated with heat-resistant spores ingested
      • Incorrectly stored cooked meat dishes, gravy, dairy products
    • Toxin production in vivo:
      • Multiplication in small intestine
      • Sporulation + enterotoxin production
    • Incubation 8-24 hours
    • Profuse diarrhea, occasionally vomiting
    • Lasts 1-3 days

    Toxins: Clostridium botulinum

    • Food contaminated with toxin (neurotoxin) ingested
      • Improperly canned products, home bottled products e.g. pickles, honey
    • Incubation 12-36 hours
    • Toxin absorbed from GIT into bloodstream
      • Binds irreversibly to presynaptic nerve endings (peripheral and cranial nerves)
      • Inhibits acetylcholine release
    • Acute descending symmetrical weakness / bilateral cranial nerve palsies
      • Paralysis, mechanical ventilation required
      • High mortality - 20%
    • Treat with anti-toxin

    Campylobacter spp.

    • Most common cause of bacterial food poisoning in developed countries
    • 4 species associated with human disease:
      • C. jejuni (most common), C. coli, C. fetus, C. lari
    • Source: Normal flora: cattle, swine, birds
    • Zoonosis: To humans from animals/animal products
      • Carcasses/meat contaminated from faeces during slaughtering
    • Transmission: Mostly foodborne (undercooked meat, raw/contaminated milk, contaminated water/ice), person-person via faecal oral route (less common)
    • Cases peak in summer

    Campylobacter spp: Pathogenesis

    • Adheres to jejunum and ileum
      • Cytotoxin causes local damage (mucosal invasion)
      • Occasionally severe haemorrhagic necrosis of the small intestine
      • Large bowel involvement with crypt abscess formation
      • Differential Diagnosis = Ulcerative colitis
    • Bloodstream spread in some people

    Campylobacter spp: Clinical Features

    • Incubation period: 2-4 days (can be up to 8-9 days)
    • Clinical features: Prodromal illness (fever, headache), diarrhoea (may be bloody), abdominal pain (can be severe)
    • Resolves 5-7 days
    • Complications: Toxic megacolon, Bacteraemia, Guillain-Barre syndrome

    Campylobacter spp: Laboratory Diagnosis

    • Typical curved-shaped, Gram negative bacilli on Gram stain
    • Greyish colonies on selective charcoal-containing media incubated in CO2 at 42°C
    • Positive oxidase test
    • Hydrolyses hippurate
    • PCR (faeces)
    • Culture (faeces/blood)

    Campylobacter spp: Treatment

    • Rehydration
    • Antibiotics not routine for gastroenteritis
      • Only if bacteraemic or immunosuppressed
      • Azithromycin or Ciprofloxacin if susceptible
    • Prevention: Good food hygiene (cooking/storing of meat/poultry), hand hygiene after contact with animals, meat etc.

    E.coli Associated with Gastroenteritis

    • Not the same E.coli that cause UTI
    • Types: Enterohaemorrhagic E.coli (EHEC), Enterotoxigenic E.coli (ETEC), Enteropathogenic E.coli (EPEC), Enteroinvasive E.coli (EIEC), Enteroaggregative E.coli (EAggEC)

    1. Enterohaemorrhagic E.coli (EHEC)

    • Major reservoir: Cattle and other ruminants
      • Survive for long periods in environment
    • Transmission: Food (minced beef products), contaminated environment (direct/indirect contact with animals or their faeces), Person to person
    • Outbreaks: Often linked to undercooked minced beef, petting animals, water, unpasteurised milk
    • Serotype O + H antigens
      • E.coli O157:H7 most common
      • Particularly serious in infants (bloody diarrhoea and renal failure)

    1. Enterohaemorrhagic E.coli: Pathogenesis

    • Site of infection = colon
    • Adherence + invasion of intestinal epithelial cells
    • Shigella-like Vero toxin (cytotoxin)
      • Cell death by disrupting protein synthesis
      • Acute inflammatory response and tissue destruction
      • Bloody diarrhoea

    1. Enterohaemorrhagic E.coli: Clinical Presentation

    • Incubation period: ~3 days (range 1-10 days)
    • Bloody diarrhoea +/- vomiting
    • More severe in extremes of age
    • Lasts 3 days

    1. Enterohaemorrhagic E.coli: Complications

    • Haemolytic uremic syndrome:
      • 10% children < 10 yrs
      • Acute renal failure
      • Thrombocytopaenia
      • Microangiopathic haemolytic anaemia

    1. Enterohaemorrhagic E.coli: Diagnosis & Management

    • Diagnosis: PCR (faeces), Culture in reference lab to confirm
    • Management: Rehydration, Antibiotics not indicated
      • Increased toxin release -> further cell death and worsening of symptoms
      • Require isolation in hospital (Contact precautions)

    2. Enterotoxigenic E.coli (ETEC)

    • Underdeveloped countries/regions of poor sanitation
    • Short incubation period 1-3 days
    • Symptoms: Watery (non-bloody) diarrhea, fever and nausea (minor discomfort to severe cholera-like syndrome)
    • Self-limiting 1-5 days

    2. Enterotoxigenic E.coli: Pathogenesis

    • Site of infection: small intestine
    • Adherence, does not invade
    • Enterotoxins = secretion of fluid and electrolytes resulting in diarrhea:
      • LT (heat-labile): Similar to cholera toxin
      • ST (heat-stable)

    3. Enteropathogenic E.coli (EPEC)

    • Major cause of Infantile gastroenteritis: < 6 moa in developing countries
    • High mortality rate (severe dehydration)
    • Person-person spread
    • May cause outbreaks

    3. Enteropathogenic E.coli: Pathogenesis

    • Site of infection: small intestine
      • Attach to intestinal mucosa
      • Loss of villi
      • Invasion of host cells and interference with normal cellular signal transduction = symptoms
    • Watery diarrhea, vomiting, fever

    Listeria monocytogenes

    • Grows in a wide range of temperatures (2-37°C)
    • Infection peaks in warmer months
    • Transmission: Contaminated milk, certain soft cheeses, pate, etc.

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    Description

    This quiz covers the basics of enteric infections, focusing on gastroenteritis and food poisoning. You will learn about the causes, epidemiology, and various infectious agents involved in these illnesses. Test your knowledge on transmission methods and the significance of reporting to public health authorities.

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