Hepatitis A Definition, Diagnosis, Treatment And Prevention
Viral hepatitis refers to the clinically important hepatotrophic viruses responsible for hepatitis A (HAV), hepatitis B (HBV), delta hepatitis (HDV), hepatitis C (HCV), and hepatitis E (HEV). Viral hepatitis has acute, fulminant, and chronic clinical forms defined by duration or severity of infection.
Acute viral hepatitis is a systemic viral infection of up to but not exceeding 6 months in duration that produces inflammatory necrosis of the liver. Chronic viral hepatitis describes prolongation or continuation of the hepatic necroinflammatory process 6 months or more beyond the onset of the acute illness.
- HAV infection is one of the most frequently reported vaccine-preventable diseases in the United States.
- The incidence of HAV correlates directly with poor sanitary conditions and hygienic practices. HAV infection occurs primarily from person-to-person transmission.
- HAV infection usually produces a self-limited disease with a low case-fatality rate. The disease may last up to 6 months in three phases: incubation, acute hepatitis, and convalescence. Most patients have full clinical and biochemical recovery within 12 weeks.
- The minimal degree of liver cell damage with HAV is reflected by mild elevations of serum transaminases values to about twice normal.
- The average incubation period is 28 days, with a range of 15 to 50 days.
- No cases of a chronic carrier state or chronic hepatitis have been reported with HAV.
Treatment of Hepatitis A :
- Management of HAV infection is primarily supportive, including a healthy diet, rest, maintenance of fluid balance, avoidance of hepatotoxic drugs and alcohol.
- Pharmacologic agents offer no clear benefit in the treatment of HAV.
Prevention of Hepatitis A :
- The spread of HAV can be best controlled by avoiding exposure. The most important measures to avoid exposure include good hand-washing techniques and good personal hygiene practices.
- The current vaccination strategy in the United States includes vaccinating: (1) children in states, counties, and communities with consistently elevated rates of hepatitis A, (2) persons in groups at increased risk for HAV infections, such as international travelers, and (3) persons at risk of adverse outcomes, such as those with chronic liver disease.
- HAV vaccines given preexposure demonstrate protective efficacy in 94% to 100% of vaccines within 1 month after primary vaccination. When a booster dose is given 6 months later, essentially 100% of recipients develop high antibody levels.
- Immunization is indicated for individuals aged 2 years or older who are at increased risk of hepatitis A infection.
- Prevention of HAV has traditionally focused on avoiding exposure as well as preexposure and postexposure prophylaxis with IG.
- A single dose of IG of 0.02 mL/kg intramuscularly (IM) is recommended for travelers to high-risk areas if travel is for less than 3 months. For lengthy stays, 0.06 mL/kg IM should be given every 3 to 5 months. Dosing is the same for adults and children.