Foodborne

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Foodborne Waterborne Disease Viruses
1. Introduction
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• Foodborne and waterborne disease viruses
• Top 3 foodborne disease outbreak during
  1988-1997(10 years) following bacteria and
  chemical
• Data from CDC most updated
• unknown etiology was 64
• passive record

Suphachai DVM, MPVM, PhD
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Outbreak by etiology 1988-1997
Etiology Outbreak Bacteria
28 Chemicals 5.6 Parasites
0.7 Viruses 1.9 Known etiology 36.6 Unknown
etiology 63.7
Source CDC 1996 Surveillance for foodborne
disease outbreaks-US 1988-1992 MMWR 45(ss-5)
1-71 CDC 2000 Surveillance for
foodborne disease outbreaks-US 1993-1997 MMWR
49(ss-1) 1-62
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Estimated cases by etiology

• Etiology Cases
• Bacteria 13.47
• Parasites 6.58
• Viruses 79.95
• Noroviruses 59.54
• Rotavirus 10.10
• Astrovirus 10.10
• Hepatitis A virus 0.22

Source Mead, et al 1999. Food related illness
and death in the United Stated Emerging
Infectious diseases 5(5) 607-625
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• Foodborne and waterborne viruses
• Estimated Top 1 of food-related illness
• Higher than bacteria parasites combined

Suphachai DVM, MPVM, PhD
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• Common properties among FB-WB viruses
• inert transmissible particles
• fecal-oral route
• human specific
• non-cytopathic effect
• non-enveloped viruses

Suphachai DVM, MPVM, PhD
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• Common properties of FB-WB disease viruses
• 1. inert transmissible particles
• viruses are not a living organism
• diameter of lt 30 nanometers (mostly)
• icosahedral symmetry
• single stranded RNA () (mostly)
• RNA-dependent RNA polymerase(RdRp)
• intracellular parasites

Suphachai DVM, MPVM, PhD
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What is VIRUS ?
A group of infectious agents characterized by
their inability to reproduce outside of a living
host cell. Viruses may subvert the host cells'
normal functions, causing the cell to behave in a
manner determined by the virus.
Virion Virus particle Infectious (native) or
noninfectious
Suphachai DVM, MPVM, PhD
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Icosahedral symmetry
Noroviruses
Poliovirus type 1
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Nonenveloped enteric viruses in human
Diameter Nucleic acid (nm) Stranded
RNA DNA 25-38 single Astrovirus Parv
ovirus Calicivirus Coronavirus Picorna
virus 70-85 double Reovirus Adenovirus Rotav
irus
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diameter of lt 30 nanometers (mostly)
Diameter of Hepatitis A virus 28 nm
Diameter of Calicivirus 30 nm
Suphachai DVM, MPVM, PhD
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• Common properties of FB-WB disease viruses
• 2. Fecal oral route transmission
• virus ingestion -gt virus shedding
• direct transmission
• fecal-oral route
• person-to-person route
• indirect transmission
• food water
• fomite

Suphachai DVM, MPVM, PhD
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• Common properties of FB-WB disease viruses
• 3. Human adaptation
• all FB-WB disease viruses are human specific
  except Hepatitis E virus(HEV) and Tick-borne
  encephalitis virus
• associated with sanitation rather than
  undercooked meat

Suphachai DVM, MPVM, PhD
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• Common properties of FB-WB disease viruses
• 4. Difficult to culture in laboratory
• human specific
• no lab host cells or no cytopathic effect(CPE)
  renders infectivity test difficult
• RT-PCR is a leading diagnostic tool yet cannot
  differentiate infectious and inactivated viruses

Suphachai DVM, MPVM, PhD
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• Common properties of FB-WB disease viruses
• 5. Non-enveloped viruses
• all FB-WB disease viruses are non-enveloped
• resistant to environmental condition e.g. pH,
  heating, UV

Suphachai DVM, MPVM, PhD
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• Foodborne and Waterborne Disease Viruses
• 1. Noroviruses(NV) formerly Norwalk-like viruses
• 2. Rotaviruses
• 3. Hepatitis A virus(HAV)
• 4. Hepatitis E virus(HEV)
• 5. Other viruses
• Astrovirus
• Parvovirus
• Tick-borne encephalitis virus
• Enteroviruses
• Adenovirus
• Coronavirus

Suphachai DVM, MPVM, PhD
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