Hepatitis E is a viral Disease caused by Hepatitis E virus (HEV). Clinically it is similarly to Hepatitis A. This virus was initially called non-A, non-B (NANB) hepatitis as the serological and morphological examinations proved no involvement of HAV or HBV. This disease is an enteric disease. The virus spread by fecal-oral route. It is responsible for waterborne outbreaks in South East Asia, South America, and in many African countries. It is present in Pakistan in endemic form. Major
epidemics have been reported in urban population, such as Karachi, Sargodha, and Islamabad where community or municipal water supply was not perfectly safe. The most important epidemic occurred in Islamabad in 1994 involving more than 4000 persons.
CHARACTERISTICS OF HEV
HEV is a small RNA virus, which appears to be a member of the caliciviridae family. It is spherical, icosahedral, and unenveloped virus, approximately 29-32 nm in diameter. Within the protein capsid, there is a single stranded RNA that acts as a positive-strand. It resembles HAV in its many structural characters.
PATHOGENESIS
HEV is excreted in the stools of the patients and spreads by the fecal-oral route. Transmission usually occurs through drinking of polluted water and ingestion of fecal contaminated food. Another important factor that promotes its transmission is poor personal and community hygiene. Person to person transmission is uncommon. Hepatitis is a leading cause of acute viral hepatitis in young to middle-aged adults in developing countries.
The process of replication of HEV, taking place in the cells of intestinal tract, is similar to HAV.
CLINICAL FEATURES
The incubation period of hepatitis E is 15-60 days, with an average of 40 days. The disease is generally mild and the symptoms are usually abrupt. The symptoms are similar to other types of viral hepatitis. The most prominent symptoms include malaise, anorexia, nausea, vomiting, abdominal pain, and fever. Jaundice may develop in young to middle-aged adults. The disease may be anicteric and/or subclinical in younger groups. It is very sever in pregnant women and is responsible for a very high mortality rate (15-20%) in this group. The disease does not turn to become chronic.
PREVENTION
There is currently no vaccine or immune gammaglobulin available to prevent the
transmission of HEV. The measures, which are currently considered effective are those usually used against many other enteric diseases. Those of prime importance are provision of safe drinking water, scientific disposal of waste water, improved personal and community hygiene, and avoiding uncooked shellfish, fruits, and vegetables particularly in endemic areas.
