HEPATITIS A and virus(HAv) Hepatitis a is caused by infection with the hepatitis a virus, which is an RNa virus in the picornavirus family Only one single serotype worldwide has been discovered. unlike some other viruses that have subtypes Acute disease and asymptomatic infection No chronic infection Protective antibodies develop in response to infection confers lifelong immunity
HEPATITIS A and Virus(HAV) • Hepatitis A is caused by infection with the hepatitis A virus, which is an RNA virus in the picornavirus family. • Only one single serotype worldwide has been discovered, unlike some other viruses that have subtypes. • Acute disease and asymptomatic infection • No chronic infection • Protective antibodies develop in response to infection - confers lifelong immunity
27nm icosahedral. first identified in 1973 HAV (7478 bases) 27 VPg
HAV' 27nm,'icosahedral.'First'iden%fied'in'1973
Stability of HAV Stable to ac at pH 3 Solvents(ether, chloroform) detergents salt water, groundwater(months) drying(stable) temperature 4℃: weeks 56C for 30minutes stable 61 Cfor 20minutes: partial inactivation Extra precautions in dealing with HAV products
Stability of HAV Stable to: acid at pH 3 Solvents (ether,chloroform) detergents salt water, groundwater(months) drying(stable) temperature 4℃: weeks 56℃for 30minutes: stable 61℃for 20minutes: partial inactivation * Extra precautions in dealing with HAV products !
Stability of HAV Inactivated by chlorine treatment of drinking water formalin(0.35%, 37C, 72hours) acetic acid(2%, 4hours) B-propiolactone(0.25% Thours)(β-乙丙内酯) Ultraviolet radiation (2u w/cm/min autoclaving, boiling in water for 5 minutes dry heat at 1 80 for l hour
Stability of HAV Inactivated by: chlorine treatment of drinking water formalin(0.35%, 37℃, 72hours) acetic acid(2%, 4hours) B-propiolactone (0.25%,1hours)（β-乙丙内酯） Ultraviolet radiation (2µW/㎝2/min) Autoclaving, boiling in water for 5 minutes, dry heat at 180 for 1 hour
HAV infection 1. Entry into mouth 2. Viral replication in the liver 3. Virus present in blood and feces 10-12 Oral days after infection acquisition 4. Virus excretion may continue for up to 3 weeks after onset of symptoms crosses nosta sBlood Bile Stool
1. Entry into mouth 2. Viral replication in the liver 3. Virus present in blood and feces 10-12 days after infection 4. Virus excretion may continue for up to 3 weeks after onset of symptoms HAV'infec%on