Microbiology Unit 5

• most common viral infection
• aka HAV or infectious hepatitis
• HAV is very resistant to surface disinfection, can remain on fomite up to 3 weeks
• No carrier state as there is a complete recovery

fecal-oral route often from eating contaminated food or water, raw oysters or food service workers with poor hygiene

• jaundice, RUQ pain, liver function impairment
• incubation is 2-4 weeks (shortest)

• liver function tests includes AST and ALT (which indicates liver damage)
• Hepatitis A antibodies (IgM-acute and IgG persist indefinitely)

• vaccines available for babies
• vaccines available for adult, 2 doses, lasts 10 years
• give Hepatitis Immune globulin if there is a known exposure
• HAV is very resistant to surface disinfection, can remain on fomite up to 3 weeks.
• No carrier state as there is a complete recovery

• aka serum hepatitis or HBV
• about 10% will complicate as Chronic Active Hepatitis B

• Heterosexual sex is most common
• IV, percutaneous (tattoos, body piercing, dialysis)
• homosexual sex especially in males
• IV drug using (sharing males)
• perinatal - babies can get this via vaginal birth
• blood transfusion - small risk if donor is in the window period because the virus is circulating early in infection; blood test are negative as there is not enough antibody to detect

• jaundice, RUQ pain, liver function impairment
• about 10% will complicate to Chronic Active Hepatitis B -- which will continuously destroy liver cells and often death; liver cancer is also common as DNA is altered
• chronic infection is very common in babies born with HBV
• can persist for years - carrier state

• Blood tests: HbsAg, HbcAg, and HBsAb
• HbsAg is Hepatitis B Surface antigen that detects the outter shell of the virus; for acute HBV, the results will be positive
• HbcAg is the Hepatitis B Core antigen that detects the core of the virus; this is positive after 4-6 weeks after the surface is positive
• HBsAb is the Hepatitis B antibody

• for chronic cases - alpha interferon (Intron A) and Lamivudine (base analog inhibitor)
• these are used to control viral replication but liver function will still decrease

• aka HCV or non-A, non-B hepatitis or post-transfusion hepatitis
• 4 millions Americans infected
• at least 35,000 new cases every year

• blood and body fluid transmission
• IV drug use
• tattoos
• body piercing most common means of transmission now
• occasional perinatal, sexual, health care associated infections
• transfusion is minimal risk

• "silent epidemic" as most cases are asymptomatic or mild (80% have no symptom)
• chronic infection in 75-85% of the population
• destroys liver function
• most common reason for liver transplant

• lab testing available since 1994
• home testing is available
• minimal risk from blood transfusions

• treatment: interferon + ribavirin for chronic infection
• no effective treatment for acute infection
• prevention: no vaccine available, screen blood supply and only use licensed US tattoo parlors

• aka HDV or Delta hepatitis
• viral fragments - consists of RNA fragments and delta antigen, not whole virus
• "piggy back" virus with HBV

• coinfects with HBV
• blood and body fluid transmission

• double infection is more severe than HBV alone
• chronic infection may occur

test for HDV antibodies (IgM, IgG) since 1995

Vaccine with HBV

• aka HEV
• outbreaks in China due eating pig

• fecal-oral route
• waterborne epidemics in developing countries
• found in pigs also

• seen mostly in children and young adults
• mild disease if not pregnant
• if pregnant, can cause liver failure with 30% mortality rate and with fetal demise
• no carrier state or chronic liver disease

made by symptoms, travel history to endemic areas, and exclusion of other Hepatitis

• aka non A-E hepatitis
• in serum, 2% of US blood donors as blood supply is not tested
• Transmission: spreads via blood and body fluids, contaminated blood products, IV drug use, sexual contact with partners
• Symptoms: may be acute or chronic, liver failure, aplastic anemia, fatal liver disease

• Liver cancer is B, C, D, G, GBV
• Fecal Oral route in A and E
• Vaccines available in A,B

B, C, D, G, GBV

C

A and B

A

• A - is short, 2-4 weeks
• B - is long, 4 weeks - 6 months
• C - is variable, 2 weeks - 6 months

A

E

• Hepatitis D coinfects with Hepatitis B
• it is a viral fragment, consist of RNA fragments and delta antigen
• Symptoms are double infections, more severe than HBV
• chronic infection is more likely

E

G and GBV