What is Hepatitis A? Where does it occur?
Hepatitis A is an acuteinfectious disease of the liver caused by the hepatitis A virus (HAV). It is more common in regions of the world with poor sanitation and not enough safe water. There are two patterns of HAV infection depending on the region:
- In the developing world, HAV has high or intermediate prevalence, and about 90% of children have been infected by age 10.Hepatitis A infection in children produces very mild symptoms or may even remain subclinical.Since a single-time infection with HAV leads to life-long immunity, thesechildren become immune to HAV and thus don't get HAV infection during adulthood.
- In developed countries where HAV has low prevalence, the children are not exposed when young.So hepatitis A occurs occsionally in outbreaks and may affects adults also when it may produce severe symptoms.
How is Hepatitis A transmitted?
The virus spreads by the fecal–oral route, and infections often occur in conditions of poor sanitation and overcrowding. Food-borne outbreaks are not uncommon, and ingestion of street food prepared in polluted water is associated with a high risk of infection. Infected individuals have the potential to spread infection to others prior to onset of symptoms, roughly 10 days following infection.In developing countries, and in regions with poor hygiene standards, the rates of infection with this virus are high and the illness is usually contracted in early childhood. As incomes rise and access to clean water increases, the incidence of HAV decreases and is usually seen in older individuals.
What is the meaning of ‘fecal-oral route’ regarding transmission of hepatitis A?
The F diagram given below shows how diseases from fecal matter can be spread through fluids, fingers, flies, and fields.
- Fluids (Water): One way is through water. Germs from feces on the ground can get into the water (fluids) and be drunk by someone in your family.
- Fingers: The second way is through fingers, or hands that haven’t been washed after going to the toilet. These dirty hands can transmit the germs on to foods, which are then eaten.
- Flies: The third way is through flies. Flies can transfer germs from feces to food, so it’s important to keep flies and other bugs out of the kitchen area.
- Fields: The fourth way is through fields or floors. Germs can seep into crops and other sources of food if feces are not disposed of properly. To prevent field contamination, it’s important that feces are disposed on in toilets for latrines.
What are the signs and symptoms of viral hepatitis A?
Early symptoms of hepatitis A infection can be mistaken for influenza, but some sufferers, especially children, exhibit no symptoms at all. The time between infection and symptoms, in those who develop them, is between two and six weeks with an average of 28 days. Symptoms usually last less than 2months and include; fatigue, fever, nausea, appetite loss, jaundice,dark colored urine, light or clay-coloured faeces and abdominal discomfort.
How is age of patient related to symptoms?
The risk for symptomatic infection is directly related to age. Young children who are infected with hepatitis A typically have a milder form of the disease, usually lasting from 1–3 weeks, whereas adults tend to experience a much more severe form of the disease.However, in India, most of the adults have already had HAV infection during childhood, so are immune from having HAV infection again during adulthood.
How is Hepatitis A diagnosed?
Clinically hepatitis A is indistinguishable from other types of acute viral hepatitis.In adults the predominant symptom of acute viral hepatitis due to HAV is jaundice (yellowness of eyes and urine) which is usually preceded by nausea, vomiting, malaise, fever and loss of appetite (prodromal symptoms). Blood tests will reveal very high liver enzymes (AST or SGOT and ALT or SGPT > 10 × upper limit of normal) and elevated bilirubin level, indicating jaundice. Specific diagnosis is made by the detection of HAV-specific Immunoglobulin G (IgM) antibodies in the blood.
How is Hepatitis A treated?
Treatment for hepatitis A depends on symptoms and severity of infection. For mild symptoms no treatment is required and symptoms begin to resolve within few days. If symptoms are bothersome your doctor may prescribe symptomatic medication. Therapy is aimed at maintaining comfort and adequate nutritional balance, including replacement of fluids that are lost from vomiting and diarrhoea. Self medication is not advisable and may even be harmful. Recovery from symptoms following infection may be slow and may take several weeks or months.For severe acute viral hepatitis which is progressing to liver failure, hospitalization is needed.
Self medication is not advisable and may even be harmful
What are the complications of Hepatitis A?
A small proportion of patients may develop prolonged period of jaundice (Cholestatic Hepatitis). These patients may be benefit from specific drug therapy. A small proportion of patients may develop acute liver failure (Develop unconsciousness or bleeding tendency following an episode of jaundice). The risk of death from acute liver failure following HAV infection increases with age and when the person has underlying chronic liver disease (Cirrhosis). Liver transplantation may be required in these patients.
How can we prevent Hepatitis A?
There are two aspects to prevention of hepatitis A virus infection:
- Hygiene and sanitation
Adequate drinking water, sanitation, and hygiene are all essential ingredients to ensure human health. Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes as well as the treatment and proper disposal of sewage or wastewater.
The vaccine is given by injection. An initial dose provides protection starting two to four weeks after vaccination; the second booster dose, given six to 12 months later. It is recommended in individuals in endemic region and in those who are likely to be exposed due to travel.