(See also Causes of Hepatitis Causes of Hepatitis Hepatitis is an inflammation of the liver characterized by diffuse or patchy necrosis. Hepatitis may be acute or chronic (usually defined as lasting > 6 months). Most cases of acute viral hepatitis... read more and Overview of Acute Viral Hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more .)
There are 4 genotypes of hepatitis E virus (HEV). All can cause acute viral hepatitis.
Genotypes 1 and 2 usually cause waterborne outbreaks that are linked to fecal contamination of the water supply and fecal-oral person-to-person transmission. Outbreaks have occurred in China, India, Mexico, Pakistan, Peru, Russia, and central and northern Africa. These outbreaks have epidemiologic characteristics similar to hepatitis A virus Hepatitis A Hepatitis A is caused by an enterically transmitted RNA virus that, in older children and adults, causes typical symptoms of viral hepatitis, including anorexia, malaise, and jaundice. Young... read more epidemics. Sporadic cases also occur. No outbreaks have occurred in the US or in Western Europe. Most cases in the developed world occur in travelers returning from a developing country, but sporadic cases not associated with travel have been reported.
Genotypes 3 and 4 typically cause sporadic cases rather than outbreaks. Transmission is food-borne and can involve eating uncooked or undercooked meat; cases have been associated with consumption of pork, deer, and shellfish.
HEV was not originally thought to cause chronic hepatitis Overview of Chronic Hepatitis Chronic hepatitis is hepatitis that lasts > 6 months. Common causes include hepatitis B and C viruses, nonalcoholic steatohepatitis (NASH), alcohol-related liver disease, and autoimmune liver... read more , cirrhosis, or chronic carrier state; however, reports document chronic genotype 3 hepatitis E exclusively in immunocompromised patients (including organ-transplant recipients, patients receiving cancer chemotherapy, and HIV-infected patients).
Typical manifestations of viral hepatitis Symptoms and Signs Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more occur: anorexia, malaise, nausea and vomiting, and fever, followed by jaundice.
Hepatitis E may be severe, especially in pregnant women; in them, risk of fulminant hepatitis Fulminant Hepatitis Fulminant hepatitis is a rare syndrome of rapid (usually within days or weeks), massive necrosis of liver parenchyma and a decrease in liver size (acute yellow atrophy); it usually occurs after... read more and death is increased.
In the initial diagnosis of acute hepatitis Initial diagnosis of acute hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more , viral hepatitis should be differentiated from other disorders causing jaundice (see figure Simplified approach to possible acute viral hepatitis Simplified diagnostic approach to possible acute viral hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more ). If acute viral hepatitis is suspected, the following tests are done to screen for hepatitis viruses A, B, and C:
If tests for hepatitis A, B, and C are negative but the patient has typical manifestations of viral hepatitis and has recently traveled to an endemic area, IgM antibody to HEV (IgM anti-HEV) should be measured if the test is available.
No treatments attenuate acute viral hepatitis, including hepatitis E.
Preliminary studies suggest ribavirin, given for 12 weeks, has antiviral efficacy in the treatment of chronic hepatitis E.
Alcohol should be avoided because it can increase liver damage. Restrictions on diet or activity, including commonly prescribed bed rest, have no scientific basis.
Viral hepatitis should be reported to the local or state health department.
Good personal hygiene and standard universal precautions help prevent fecal-oral transmission of hepatitis E. Boiling water appears to reduce risk of infection. Because person-to-person transmission is rare, isolation of infected patients is not indicated.
A vaccine for hepatitis E is now available in China; it is not available in the US. The vaccine appears to have about 95% efficacy in preventing symptomatic infection in males and is safe. Efficacy in other groups, duration of protection, and efficacy in preventing asymptomatic infection are unknown.
Transmission of hepatitis E is usually by the fecal-oral route.
Most patients recover spontaneously, but pregnant women have an increased risk of fulminant hepatitis and death.
Genotype 3 may cause chronic hepatitis in immunocompromised patients.
Suspect hepatitis E in travelers to endemic regions; do IgM anti-HEV testing if available.
Treat patients supportively; consider using ribavirin for chronic hepatitis E.
A vaccine is available in China.