Hepatitis A is a disease which is characterized by acute inflammation of the liver caused by the hepatitis A virus. Its period of incubation (the time between the arrival of the virus in the body and the development of the disease) ranges between 15 and 49 days. The virus is transmitted by the ingestion of food contaminated with the virus, frequently raw seafood or raw vegetables that have been irrigated with fecally-contaminated water.
It is very common in children, although the majority do not show symptoms on contracting the virus. Those who develop symptoms (approximately 5% of children) show signs of nausea, coluria (Coca Cola coloured urine) and jaundice (the yellowing colouring of the skin and eyes). Some 70% of adults show symptoms. Some of those affected, less than 1%, may develop fulminant liver failure, requiring a liver transplant. Nevertheless, in the majority of cases the disease runs its course without any lasting damage and the liver regenerates itself completely.
Hepatitis A is the hepatitis virus that most frequently attacks the liver, but also the most benign. It can only be contracted once, given that the body generates permanent defences against the disease. There is no specific antiviral treatment for hepatitis A. The infection is completely preventable via a safe and highly effective vaccine that should be routinely administered to children. Those people who live under the same roof can be given an immunoglobulin to prevent infection. This is administered in intra-muscular form and is only effective during the first two weeks of contact with the patient. It is only useful for those who have not had hepatitis A previously.
Apart from the vaccine and the immunoglobin, the principal prevention measures are an improvement in food hygiene, the universal availability of drinking water and avoiding consumption of vegetables that have been irrigated with fecally-contaminated water.
- Rest: Rest is useful to the extent that the person is in low spirits and is useful for avoiding the spread of the infection in schoolmates or workmate. Nowadays, the long periods of strict bed rest that were recommended years ago are no longer prescribed.
- Diet: The diet should be light so as to reduce the nausea and vomiting that patients frequently suffer. The reduction of fat and fried food has this as its objective. During the recuperation phase it is important to moderately increase the consumption of high quality proteins (milk, eggs, meat) to help the regeneration the liver.
- Serious symptoms: There are two symptoms which indicate seriousness. The first is nausea and persistent vomiting, and secondly a certain drowsiness due to hepatic encephalopathy. The presence of these symptoms should lead to a doctor being called immediately.
- Laboratory tests: Among the laborarory tests, the most important is the prothrombin time. If this is less than 60%, it may indicate seriousness. A bilirubin above 10 mg/dL is another indicator of severity. The diagnosis of this type of hepatitis is made via the IgM HAV (immunoglobin M of hepatitis A) in the blood. The transaminase refer to the level of the enzymes SGOT (AST) and SGPT (ALT) in the blood. Usually they are elevate above 1000 U/ml, but the degree of the elevation does not have a direct relation with the seriousness of the hepatitis. Billirubin is generally elevated, and this substance explains the yellow colouring of the skin and the eyes. The level of transaminase decreases gradually over the course of one or two months.
- Course of the hepatitis: Some people may experience the reappearance of symptoms after an apparent recovery. This is not a sign of a bad prognosis. A small percentage of patients show symptoms of “cholestasic” hepatitis, which is manifested by intense pruritus (itching) of the skin and a marked yellow colour of the skin (due to bilirubin elevation). On occasions corticoids are used for these cases. Hepatitis A generally lasts no more than six months. Chronic hepatitis due to hepatitis A virus infection does not exist.