Hepatitis E Hepatitis E is a viral hepatitis (liver inflammation) caused by infection with avirus called hepatitis E virus (HEV). It is one of five known human hepatitisviruses: A, B, C, D, and E. HEV is a positive-sense single-stranded RNA icosahedral virus with a 7.5 kilobase genome. HEV has a fecal-oral transmission route. Infection with this virus was first documented in 1955 during an outbreak in New Delhi, India.[1] A preventative vaccine (HEV 239) is approved for use in China.

Although Hepatitis E often causes an acute and self-limiting infection (it usually goes away by itself and the patient recovers).

SymptomsAcute infection:The incubation period of hepatitis E varies from 3 to 8 weeks. After a short prodromal phase symptoms lasting from days to weeks follow. They may include jaundice, fatigue and nausea. The symptomatic phase coincides with elevated hepaticaminotransferase levels.

Chronic infection:

While usually an acute disease, in immunocompromised subjects—particularly in solid organ transplanted patients—hepatitis E may cause a chronic infection. Occasionally this may cause liver fibrosis and cirrhosis

ClassificationThere is only one serotype of the virus and classification is based on the nucleotide sequences of the genome. Genotype 1 has been classified into five subtypes, genotype 2 into two subtypes and genotypes 3 and 4 have been into ten and seven subtypes respectively.

TransmissionHepatitis E is prevalent in most developing countries, and common in any country with a hot climate. It is widespread in Southeast Asia, northern and central Africa, India, and Central America. It is spread mainly by the fecal-oral route due to fecal contamination of water supplies or food; person-to-person transmission is uncommon.

Prophilaxis&prevention

Sanitation:Improving sanitation is the most important measure in prevention of hepatitis E; this consists of proper treatment and disposal of human waste, higher standards for public water supplies, improved personal hygiene procedures and sanitary food preparation.

Vaccines:A vaccine based on recombinant viral proteins was developed in the 1990s and tested in a high-risk population (military personnel of Nepal) in 2001. The vaccine appeared to be effective and safe, but development was stopped for economic reasons, since hepatitis E is rare in developed countries. There is no licensed hepatitis E vaccine for use in the US.

TreatmentApart from supportive care, no specific validated treatment exists for acute hepatis E infection. Although ribavirin is not registered for Hepatitis E treatment, there is off-label experience for treating chronic Hepatitis E with this compound. The use of low doses, 600 to 800 milligrams per day, of ribavirin over a three-month period has been associated with viral clearance in about two-thirds of chronic cases. Other possible

treatments include peginterferon or a combination of ribavirin and peginterferon. 

EpidimologyThe hepatitis E virus causes around 20 million infections a year. These result in around three million acute illnesses and as of 2010, 57,000 deaths annually. It is particularly dangerous for pregnant women, who can develop an acute form of the disease that is lethal in 20 percent of cases. The virus (HEV) is a major cause of illness and of death in the developing world and disproportionate cause of deaths among pregnant women. Among indigenous people, a significant prevalence of hepatitis E virus-specific antibody has been reported in several amerindian Yupka tribes in South America