HEPATITIS A
Dr. Widjaja Luman
Consultant Gastroenterologist and General Physician
B Sc (St. Andrews), MB ChB (Man), MRCP (UK), M.D. (Edin),
CCST (UK), FRCP (Edin)
(Ahli penyakit pencernaan dan hepar)
Introduction
Hepatitis A is an acute inflammatory process of the liver as a result of infection by the hepatitis A virus. Hepatitis A is a small RNA picornavirus and is spread through the “ faecal-oral ” route. “Faecal -oral route” means that the virus is passed from the faeces of an infected person to the digestive tract of another person through ingestion of contaminated food or water (through the mouth). The average incubation period for hepatitis A is 28 days ( range : 15 – 50 days ). This means that the infected person does not become ill until 28 days after ingestion of the virus.
What are the signs and symptoms of hepatitis A ?
Generally adults are more likely to have symptoms (or become ill) than children. Some infected patients (especially children) may be asymptomatic. The symptoms and signs include :-
- Fever
- Loss of appetite
- Nausea
- Abdominal discomfort
- Dark urine
- Tiredness
- Yellowing of skin and eyes ( jaundice )
- Vomiting
- Joint pains
Infected persons are usually unwell for one week but some persons may take up to 2 months to fully recover. In a few cases, infected person may remain unwell for up to 6 months. Some individuals may suffer symptomatic relapse in 2-3 months after initial recovery.
Hepatitis A is a self-limiting disease. However, in less than 1% of patients, largely in the elderly, the disease may progress to liver failure ( fulminant hepatitis ) and death. Chronicity to carrier state does not occur with the hepatitis A.
How is hepatitis A transmitted ?
As alluded to previously, the principal mode of transmission is via the “fecal-oral” route. Thus, hepatitis A is prevalent in areas where there are poor sanitary conditions and quality control of food hygiene. Most infections are spread by food or drinks contaminated by sewage water for e.g. contaminated raw shell fish. Food vendors who are infected may also spread the disease if they fail to practice good personal hygiene. Rarely hepatitis A can be transmitted by intravenous drug usage, blood products and amongst practicing homosexual men.
Is there any treatment for hepatitis A infection ?
Hepatitis A is a self-limiting disease. There is no specific treatment for the illness. Symptomatic treatment for fever and nausea can be prescribed. Adequate rest is required. Oily food should be avoided as it causes nausea. Smokers commonly experience nicotine intolerance when they are unwell; this is perhaps a good opportunity to give up smoking.
Infected persons should observe good personal hygiene to prevent spread to others. Admission to hospital is indicated if the patient’s symptoms become worse ( eg intractable vomiting, dehydration and signs of impending liver failure ). Most of the time infected persons can rest at home with regular follow up by their physicians.
How can hepatitis A be prevented ?
Besides observing good personal hygiene, and avoidance of eating raw seafood and water contaminated with sewage, a more specific measure would be immunization. Such general measures would apply especially if one is travelling or living in areas where hepatitis A is endemic like Southeast Asia (including Singapore), Mexico, Caribbean, South & Central America, Africa and Eastern Europe.
Hepatitis A vaccine consists of the virus in an inactivated form. It is given in 2 doses, with the second dose being given 6 – 12 months apart. Almost all individuals will mount adequate antibody after completion of the vaccination. Immunity is expected to be life long. Protection against hepatitis A begins 4 weeks after vaccination. Travellers should consider vaccination 4 weeks before departure. It should not be given for women in pregnancy and lactation because of the theoretical risk to the developing foetus. It can however be used in immunocompromised patients for e.g. persons on hemodialysis or persons with AIDS.
Who should receive the hepatitis A vaccine ?
Hepatitis A vaccination is often not part of the vaccination programme in childhood. However, most children in developing are infected during childhood and they suffer from very mild illness. As a result, most adults in developing countries have already got antibody through their childhood infection. In general, for individuals who do not have antibody against hepatitis A, vaccination is recommended if:
- They are travelling to or working in endemic areas.
- Persons with chronic liver disease e.g. chronic hepatitis B carriers as these patients have been reported to have a higher mortality if they have superimposed acute hepatitis A infection.
- c) Hepatitis A vaccination is recommended for workers in these industries (Sewerage workers /Food service industries / Health care sectors / Day-care attendees).