Hepatitis E is a liver infection caused by the hepatitis E virus (HEV). HEV is found in the stool of an infected person. It is spread when someone unknowingly ingests the virus – even in microscopic amounts. In developing countries, people most often get hepatitis E from drinking water contaminated by feces from people who are infected with the virus. Symptoms of hepatitis E can include fatigue, poor appetite, stomach pain, nausea, and jaundice. However, many people with hepatitis E, especially young children, have no symptoms. Except for the rare occurrence of chronic hepatitis E in people with compromised immune systems, most people recover fully from the disease without any complications. No vaccine for hepatitis E is currently available.
HEV is usually spread by the fecal-oral route. In developing countries, where HEV genotypes 1 and 2 predominate, the most common source of HEV infection is contaminated drinking water. In developed countries, sporadic cases of HEV genotype 3 have occurred following consumption of uncooked/undercooked pork or deer meat. Consumption of shellfish was a risk factor in a recently described outbreak that occurred among cruise ship passengers (5). HEV genotype 4, detected in China, Taiwan, and Japan, has also been associated with foodborne transmission.
Hepatitis E can infect certain mammals, and consumption of uncooked/undercooked meat or organs from infected animals can lead to foodborne transmission to humans. HEV RNA (genotypes 3 and 4) has been extracted from boar, and deer meat.
When they occur, the signs and symptoms of hepatitis E are similar to those of other types of acute viral hepatitis and liver injury. They include:
The ratio of symptomatic to asymptomatic infection ranges from 1:2 to 1:13.
HEV infection should be considered in any person with symptoms of viral hepatitis who tests negative for serologic markers of hepatitis A, hepatitis B, hepatitis C, other hepatotropic viruses, and all other causes of acute liver injury. Any symptomatic person who has traveled either to or from an hepatitis E-endemic area or outbreak-afflicted region should also be evaluated for HEV infection. A detailed history regarding travel, sources of drinking water, uncooked food, and contact with jaundiced persons should be obtained from these patients to aid in diagnosis. Because domestically acquired cases of hepatitis E are occurring in the Pakistan, HEV infection also should be considered in any person with unexplained symptoms of liver injury, regardless of travel history.
Because cases of hepatitis E are not clinically distinguishable from other types of acute viral hepatitis, diagnosis can be confirmed only by testing for the presence of antibody against HEV or HEV RNA.
Prevention of hepatitis E relies primarily on good sanitation and the availability of clean drinking water. Travelers to developing countries can reduce their risk for infection by not drinking unpurified water. Boiling and chlorination of water will inactivate HEV. Avoiding raw pork and venison can reduce the risk of HEV genotype 3 transmission. Immune globulin is not effective in preventing hepatitis E.
No approved vaccine for hepatitis E is currently available in the Pakistan; however, in 2012 a recombinant vaccine was approved for use in China.