This happens when food or water contaminated by the HAV is ingested a person who is not immunized to this virus. It is closely associated with unsafe water, inadequate sanitation and poor personal hygiene.
Unlike hepatitis B and C, the infection does not cause chronic liver disease and is rarely fatal, though it cause debilitating symptoms and fulminate hepatitis i.e. acute liver failure which is associated with high mortality.<br />
The occurrences of hepatitis are sporadic, epidemic and have a tendency to be cyclic in recurrence. It is frequently food borne and can resist food-production processes routinely used to inactivate and/or control bacterial pathogens.
A break of HAv can lead to significant economic and social consequences in the community. For it takes weeks or months for people to recover from the illness and return to everyday life. It would also impact the establishment identified as the source of infected food, causing indirect effect on the local productivity.
Geographically the distribution can be characterized as having high, intermediate or low levels of hepatitis. Areas with high levels of infection are seen in developing countries with poor hygiene and sanitation practise most children below the age of 10 have already been infected as the infection is subclinical it goes unnoticed. Infection in older children and adults are rare. Disease rates and outbreak identification is low in these areas. Areas with intermediate infection are seen in developing countries with transitional economy and sanitary conditions are variable. Children could escape childhood infection but become susceptible at an older age. Higher disease rates and large outbreaks could be seen here. Developed countries are areas of low level infection. Here the sanitary and hygiene conditions are good. so infection occurs in a group that is high-risk for Hepatitis in general, they are the injecting-drug users, the homosexual, and people travelling to regions of high endemic potential, or people in isolated closed religious communities.
HAV transmits through the faecal-oral route. That is when a person ingests contaminated food or water. Water borne epidemic are rare, however when they do occur they are associated with sewage contamination or inadequate treatment of water. Transmission through physical contact is a possibility in the case of homosexuals.
The symptoms of HAV usually manifests after 14 — 28 day incubation. This manifestation could range from mild to severe, and the range includes, fever, malaise, loss of appetite, diarrhoea, nausea, abdominal discomfort, dark coloured urine and yellowing of skin and the white of eye. This yellowing is commonly called Jaundice.
The severity of the disease and mortality increases with age. Symptoms and signs are also more pronounced in adults.<br />
Anyone who is not immunized is a high risk person that would be people who are not vaccinated. The risk factors are<br />
• Poor sanitation<br />
• Lack of safe water<br />
• Injecting drugs<br />
• Living in a household with infected person<br />
• Being a sexual partner with an infected person<br />
• Travelling to area of endemic potential without immunization.<br />
Diagnosis–HAV is not clinically distinguishable from other strains; specific detection would require detecting the IgM and IgG antibodies specific to HAV. Additional tests like reverse transcriptase polymerase chain reaction would require specialized laboratory facilities.
There is no specific treatment for HAV, therapy is aimed at maintaining comfort and nutritional balance, replacement of lost fluids due to vomiting and diarrhoea. The recovery is slow and may take several weeks to months.
Prevention is possible with improved sanitation, food safety and immunisation. Organization of proper sewage disposal, regular personal hygiene practise and of course vaccination. However no vaccine is authorized for children below a year. A single dose provides immunity after a 2 weeks or a maximum of a month after exposure. This can be administered as a part of child immunization program, and for travellers to high endemic potential areas.<br />
The immunization effort should be part of a comprehensive plan for the prevention and control. Planning for large-scale immunization programs should involve economic evaluations and consider alternative or additional prevention methods such as improved sanitation and health education for improved hygiene practise.
The inclusion of HAV as part of childhood immunization schedule should be the call of the local preventive health care. Some countries use two dose system while many countries are comfortable with single dose inactivated hepatitis A. The vaccine is particularly recommended for high risk group like—
• Travellers to endemic area.<br />
• Male homosexuals<br />
• People with chronic liver disease<br />
WHO works to prevent and control viral hepatitis by<br />
• Raising awareness, promoting partnerships and mobilizing resources<br />
• Formulating evidence based policy and data for action.<br />
• Prevention of transmission<br />
• Executing screening. Care and treatment.<br />
Hepatitis A is a liver disease that ranges from mild to severe. Globally 1.4 million cases are reported every year.HAV is transmitted through ingestion of contaminated food, water or through direct physical contact with an infected person. HAV endemics are associated with lack of safe water and poor sanitation. These epidemics could cause significant economic loss as recovery is slow. Improving sanitation and personal hygiene along with vaccination are the effective ways of combating the disease.