Hepatitis a virus (HAV) is a small sized (27nm), RNA virus of the family picornaviridae. It can be inactivated by boiling for one minute or by exposure to UV-light, chlorine and formaldehyde.
Hepatitis A Transmission
- HAV is transmitted by faeco-oral route.
- Infection is acquired by consumption of contaminated food or water.
- Person to person spread is common mode of transmission.
- Viral excretion in stools of infected person begins few days to two weeks prior to onset of symptoms and decline after jaundice appears.
- Incubation period is 15 to 50 days.
- There is no animal reservoir of this infection.
Symptoms Of Hepatitis A
- Clinical presentation can range from asymptomatic infection to fulminant hepatic failure.
- Commonly, acute hepatitis illness occurs with an abrupt onset.
- Initial symptoms are fever, malaise, fatigue, anorexia and vomiting.
- Some patients have an aversion to food and smoking.
- These are soon followed by dark colored urine and appearance of jaundice.
- Some patients may notice clay colored stools and itching.
- Fever is usually mild to moderate, not associated with chills and improves as jaundice appears.
- Jaundice remains for a few weeks and then gradually improves.
- Clinical examination usually shows icterus (yellowish discoloration of the sclera) and slightly enlarged, mildly tender liver.
- The illness lasts for less than eight weeks.
- HAV causes self limiting illness with usually no sequence.
- It does not lead to chronic carrier state, chronic hepatitis or cirrhosis of liver.
Hepatitis A Diagnosis
- Diagnosis of HAV infection is based on detection of antibodies against HAV in serum.
- IgM HAV are 1st to appear and can be detected in early course of illness. Therefore presence of IgM anti-HAV in serum suggests a recent HAV infection.
- Presence of IgM anti-HAV on the other hand suggests an infection sometimes in the past and that the individual is immune to HAV infection.
- Diagnosis of acute infection can also be made by detection of viral particles in stool specimens.
Hepatitis A Treatment And Prevention
- No specific treatment is available for HAV infection, since the illness is mild and self-limiting.
- Bed rest and dietary precautions like fat restriction, liberal use of sugars and carbohydrate are prescribed.
- Transmission of HAV can be prevented by ensuring clean and safe water supply and by following hygienic food preparation and consumption practices.
- For HAV infection, specific immuno-prophylaxis, both active and passive is possible.
Hepatitis A Vaccination
- Intra-muscular administration of immune serum globulin before or soon after exposure to HAV infection leads to a milder infection. Protective effect of this dose lasts for 2 to 3 months.
- Use of immune serum globulin is recommended in persons who are not previously exposed and are at risk of getting this infection like travelers.
- Passive immunization is recommended for household and day care centre contact of patients with HAV.
- Related Topics
- Hepatitis D Symptoms, Transmission: Hepatitis Delta Virus Prevention
- Hepatitis E Symptoms And Transmission: Treatment For HEV Infection
- Viral Hepatitis Symptoms, Treatments | Chronic Hepatitis Diagnosis
- Hepatitis In Children: Symptoms, Causes And Prevention Of Hepatitis
- Autoimmune Hepatitis: Types, Clinical features And Treatment
