1 / 29

Foodborne & Waterborne Disease Viruses

Suphachai Nuanualsuwan DVM, MPVM, PhD. Foodborne & Waterborne Disease Viruses. 3. Hepatitis viruses. Hepatitis-causing viruses. Suphachai DVM, MPVM, PhD. Type Nucleic acid Alias Transmission HAV (+)ssRNA Infectious hepatitis Fecal-oral

yaholo
Download Presentation

Foodborne & Waterborne Disease Viruses

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Suphachai Nuanualsuwan DVM, MPVM, PhD Foodborne & Waterborne Disease Viruses 3. Hepatitis viruses

  2. Hepatitis-causing viruses Suphachai DVM, MPVM, PhD

  3. Type Nucleic acid Alias Transmission HAV (+)ssRNA Infectious hepatitis Fecal-oral HBV dsRNA Serum hepatitis Parental HCV (+)ssRNA Non-A Non-B Parental HDV (-)ssRNA Hepatitis delta Parental HEV (+)ssRNA Non-A Non-B Fecal-oral Hepatitis-causing viruses Suphachai DVM, MPVM, PhD

  4. Hepatitis A virus(HAV) • 1. Virus particle • hepatovirus, picornaviridae • single serotype • 28 nm • (+)ssRNA Suphachai DVM, MPVM, PhD

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

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

  7. Hepatitis virus migrating to liver intestine

  8. Hepatitis virus shedding to intestine Suphachai DVM, MPVM, PhD

  9. Hepatitis A virus(HAV) • 3. Disease pattern Suphachai DVM, MPVM, PhD

  10. 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

  11. Hepatitis A virus(HAV) 3. Disease pattern Suphachai DVM, MPVM, PhD

  12. 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

  13. Discharge untreated sewage straight into the sea

  14. Hepatitis A virus(HAV) • 5. Epidemiology • Worldwide epidemic

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

  16. Sewage discharge Beach Estuarine Seashore Suphachai DVM, MPVM, PhD

  17. Hepatitis A virus(HAV) • Foodborne and waterborne disease virus • shellfish and sanitation • children < 5 yr are carrier and asymptomatic • incubation period ~ 48 days(long) • virus shedding in stool before onset of illness Suphachai DVM, MPVM, PhD

  18. 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

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

  20. Hepatitis E virus(HEV) • 3. Disease pattern • liver inflammation -> 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

  21. Clinical illness ALT IgG anti-HEV IgM anti-HEV Virus in stool Titer Week after exposure Hepatitis E virus(HEV) 3. Disease Pattern Suphachai DVM, MPVM, PhD

  22. 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

  23. Hepatitis E virus(HEV) • 4. Transmission/ Control • Fecal-oral route • water supplies • sanitation Suphachai DVM, MPVM, PhD

  24. 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

  25. Phylogenetic relationships between HEV isolates

  26. Geographic distribution of Hepatitis E

  27. 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

  28. 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

More Related