Hepatitis means inflammation of the liver. Hepatitis A is a highly contagious virus which causes about 20 to 40% of clinically apparent hepatitis. Hepatitis A is most common where people live in overcrowded conditions with poor sanitation. However, anyone can become infected and carry the disease with them into other areas. It is therefore, a worldwide problem. Outbreaks and epidemics can occur just about anywhere. The highest incidence of the infection is in children, since they are not very aware of hygienic precautions. Hepatitis A can spread rapidly within schools and other institutions such as day care centers.

Causative Factor
Hepatitis A is caused by the enterovirus.

Clinical Features

Liver
• Fever.
• Fatigue.
• Nausea and vomiting.
• Diarrhea.
• After one or two weeks, the liver may become enlarged and jaundice (yellowing) may occur.
• Yellow color in the whites of the eyes.
• The urine may become dark and stools pale.

Clinical manifestations of Hepatitis A often pass unrecognized in children younger than two years of age. The most important factor affecting the severity of the disease is age. About one in every thousand infected patients dies from liver failure.

Mode of Transmission

• The Hepatitis A virus is transmitted by the oral–fecal route.
• Through close person–to–person contact or,
• By ingesting contaminated food or water.
• The virus enters the body through the mouth. Unlike other forms of Hepatitis, body fluids are not involved in the spread of Hepatitis A.

Incubation Period
Hepatitis A usually lasts for about three to six weeks, although some subjects have prolonged or relapsing symptoms for up to six months. Patients with Hepatitis A will be a source of infection two weeks before they are ill and for about one week after they recover.

Treatment
There is no specific treatment for Hepatitis A though rest and proper nutrition could relieve some symptoms.

Prevention
Primary hygienic measures are to be taken, such as

• To wash the hands frequently.
• Boil any food that might be contaminated.
• Avoid swimming in water that might be contaminated with sewage.
• Good hygiene and sanitation reduce the risk of epidemics.

Vaccination
If you have had Hepatitis A, you will be immune to further infection and at no risk of long–term effects. However, there are reasons for protecting those who have not yet contracted the Hepatitis A virus. Vaccines have proven efficacy and safety. Vaccination provides lasting protection. Your doctor will advise you about your particular needs.
Children or adults should be vaccinated one month before protection is needed, although the vaccine may be effective within 14 days. It is sensible to vaccinate young children before entering school or day care centers.

Who should be vaccinated?
Children are more exposed to the risk of infection and least likely to be already immune. Therefore, young children are a priority for vaccination.
Adults who do not have natural antibodies and belong to groups at risk for Hepatitis A need also to be vaccinated:

• Individuals living in areas where Hepatitis A is endemic.
• Youngsters in child care facilities, their family and facility staff.
• Travelers.
• Health care workers.
• Food handlers.
• Military personnel.
• Subjects with chronic Hepatitis C or other chronic liver diseases.
• Institutionalized persons and their care givers.