Concentration of Hepatitis a virus in Various Body Fluids Feces Serum Saliva Urine 108 Infectious Doses per ml Source: Viral Hepatitis and liver disease 1984; 9-22 J Infect Dis1989160:887-890
Source: Viral'Hepa%%s'and'Liver'Disease'1984;9N22' J'Infect'Dis'1989;160:887N890' Feces' Serum' Saliva' Urine' Body Fluid Infectious Doses per ml 100 102 104 106 108 1010 Concentration of Hepatitis A Virus in Various Body Fluids
HAV infection self-limited Clinicalilness HAV in feces Alt Viremia gM Week Infection ALT= alanine aminotrasferase, a liver enzyme
HAV'infec%on:'selfNlimited' ALT='alanine'aminotrasferase,'a'liver'enzyme
Hepatitis a -Clinical Features Incubation period is usually about 30 days after exposure, the range is 15 -50 days Jaundice(turning yellow)is most commonly seen in the older patients Under 6 years old(10%) 6 to 14 years old(40-50%) Greater than 14 years old (70-80%) Fatigue Dark urine Fever Nausea(恶心) and vomiting Abdomina(腹部)pain Complications of this type of viral infection include rare liver failure and relapsing hepatitis Chronic sequelae are not seen
Hepatitis A - Clinical Features – Incubation period is usually about 30 days after exposure, the range is 15 – 50 days – Jaundice (turning yellow) is most commonly seen in the older patients • Under 6 years old (10%) • 6 to 14 years old (40 – 50%) • Greater than 14 years old (70 – 80%) – Fatigue – Dark urine – Fever – Nausea (恶心） and vomiting – Abdomina (腹部） pain • Complications of this type of viral infection include rare liver failure and relapsing hepatitis • Chronic sequelae are not seen
Hepatitis a -Clinical Features Milder disease than hepatitis B asymptomatic infections are very common, especially in children Adults, especially pregnant women, may develop more severe disease no chronic form of the disease Complications: Fulminant hepatitis is rare: 0. 1% of cases
Hepatitis A - Clinical Features • Milder disease than Hepatitis B; • asymptomatic infections are very common, especially in children. • Adults, especially pregnant women, may develop more severe disease • no chronic form of the disease. • Complications: Fulminant hepatitis is rare: 0.1% of cases
Hepatitis a virus Transmission Virus can be transmitted via fecal-oral route ingestion of contaminated food and water can cause infection HAV in shellfish is from sewage-contaminated Water Virus can be transmitted by food handlers, day- care workers and children
Hepatitis A Virus Transmission • Virus can be transmitted via fecal-oral route ingestion of contaminated food and water can cause infection • HAV in shellfish is from sewage-contaminated water • Virus can be transmitted by food handlers, daycare workers, and children