Foodborne

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Foodborne Waterborne Disease Viruses
3. Hepatitis viruses
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Hepatitis-causing viruses
Suphachai DVM, MPVM, PhD
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Hepatitis-causing viruses
Suphachai DVM, MPVM, PhD
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• Hepatitis A virus(HAV)
• 1. Virus particle
• hepatovirus, picornaviridae
• single serotype
• 28 nm
• ()ssRNA

Suphachai DVM, MPVM, PhD
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• Hepatitis A virus(HAV)
• 2. Implicated food
• shellfish
• water
• strawberry, lettuce

Suphachai DVM, MPVM, PhD
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• Hepatitis A virus(HAV)
• 3. Disease pattern
• asymptomatic kid lt 5 yr.
• acute hepatitis adult gt 14 yr.
• mild gastrointestinal illness
• incubation period 28 days(4 weeks) virus from
  GI -gt liver -gt immune response
• liver inflammation(hepatitis) -gt jaundice -gt
  liver enzyme(ALT) increase

Suphachai DVM, MPVM, PhD
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Hepatitis virus migrating to liver
intestine
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Hepatitis virus shedding to intestine
Suphachai DVM, MPVM, PhD
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• Hepatitis A virus(HAV)
• 3. Disease pattern

Suphachai DVM, MPVM, PhD
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• Hepatitis A virus(HAV)
• 3. Disease pattern
• HAV shedding in stool before onset of illness
• Immunoglobulin M rises as ALT enzyme rises
• IgM falls while IgG rises
• IgM represents recent infection
• IgG represents previous infection(permanent)
• HAV shedding 2 weeks after onset of illness

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Hepatitis A virus(HAV) 3. Disease pattern
Suphachai DVM, MPVM, PhD
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• Hepatitis A virus(HAV)
• 4. Transmission/Control
• fecal-oral
• indirect transmission associated with sanitation
• food(shellfish) and water
• fomite
• secondary infection household
• food handlers

Suphachai DVM, MPVM, PhD
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Discharge untreated sewage straight into the sea
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• Hepatitis A virus(HAV)
• 5. Epidemiology
• Worldwide epidemic

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• Hepatitis A virus(HAV)
• 5. Epidemiology
• gt 90 got infected lt 6 years
• children are carrier asymptomatic
• Shanghai China outbreak associated with raw
  sewage contaminated shellfish in the coastal
  water -gt 300,000 cases over months
• homosexual, drug users
• sanitation, institutional
• visit endemic area should get vaccinated

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Sewage discharge
Beach
Estuarine
Seashore
Suphachai DVM, MPVM, PhD
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• Hepatitis A virus(HAV)
• Foodborne and waterborne disease virus
• shellfish and sanitation
• children lt 5 yr are carrier and asymptomatic
• incubation period 48 days(long)
• virus shedding in stool before onset of illness

Suphachai DVM, MPVM, PhD
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• Hepatitis E virus(HEV)
• 1. Virus particle
• enterically Non-A Non-B(ENANB) hepatitis virus
• enterically transmitted Non-A Non-B(ET-NANB)
• similar to Calicivirus
• diameter 32 nm
• ()ssRNA 7,200 bases

Suphachai DVM, MPVM, PhD
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• Hepatitis E virus(HEV)
• 2. Implicated food
• mostly drinking water

Suphachai DVM, MPVM, PhD
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• Hepatitis E virus(HEV)
• 3. Disease pattern
• liver inflammation -gt icterus, Hepatomegaly
• cannot distinguish from other viral Hepatitis
• GI illness diarrhea, nausea, vomiting
  headache, fever
• incubation period 40 days (longer than that of
  HAV)
• illness duration 4 weeks
• illness of middle aged adults (14-40 yr.)

Suphachai DVM, MPVM, PhD
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Hepatitis E virus(HEV) 3. Disease Pattern
Suphachai DVM, MPVM, PhD
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• Hepatitis E virus(HEV)
• 3. Disease pattern
• HAV shedding in stool before onset of illness
• IgM rises as ALT rises
• IgG rises just soon after IgM
• IgM represents recent infection
• IgG represents previous infection last 2-14 yr.
• HAV shedding 2 weeks after onset of illness

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• Hepatitis E virus(HEV)
• 4. Transmission/ Control
• Fecal-oral route
• water supplies
• sanitation

Suphachai DVM, MPVM, PhD
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• Hepatitis E virus(HEV)
• 5. Epidemiology
• mortality rate 0.1-1.0
• mortality rate up to 20 in pregnant
• swine HEV and human HEV are closely related
• endemic in southeast Asia(SEA), middle Asia,
  middle east, northern Africa, and Mexico

Suphachai DVM, MPVM, PhD
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Phylogenetic relationships between HEV isolates
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Geographic distribution of Hepatitis E
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• Hepatitis E virus(HEV)
• fecal-oral route
• longer incubation period than that of HAV
• illness of adult with hepatomegaly
• serious in pregnant women
• temporary immunity

Suphachai DVM, MPVM, PhD
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• Foodborne and Waterborne Disease Viruses
• Noroviruses is most prevalent
• Rotaviruses in kid HAV, HEV in adult
• Fecal oral route
• Food shellfish Water sanitation
• preventing virus transmission
• Preventing contamination
• Inactivation e.g. heat, chlorine, UV

Suphachai DVM, MPVM, PhD
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