Hepatitis E is a liver infection caused by the hepatitis E virus (HEV). This condition is a significant public health issue across the globe, although its severity and transmission routes can differ by region. While it often results in a temporary, self-resolving illness, it can lead to more serious outcomes in specific populations.
How Hepatitis E Spreads
The most common method of HEV transmission is the fecal-oral route. This primarily occurs when an individual consumes water contaminated with the fecal matter of an infected person, a frequent issue in areas with poor sanitation. This mode of transmission is especially prevalent for specific genotypes of the virus, namely HEV-1 and HEV-2.
Zoonotic spread involves animals, and people can become infected by consuming undercooked or raw meat from them. Common sources include pork, wild boar, and venison, and contaminated shellfish have also been identified as a source. This type of transmission is typically associated with HEV-3 and HEV-4 genotypes. Less common routes include contaminated blood transfusions and vertical transmission from an infected pregnant person to their fetus.
Signs and Symptoms of Infection
Following exposure to HEV, there is an incubation period that typically lasts from two to six weeks before any signs of illness appear. However, a large number of people, especially young children, may not show any symptoms at all. When symptoms do manifest, they often include fever, fatigue, loss of appetite, nausea, and abdominal pain.
More specific signs related to liver inflammation include jaundice, which is a yellowing of the skin and eyes, dark-colored urine, and pale or clay-colored stools. Joint pain is another symptom that may occur. For most individuals, these symptoms are temporary and last for about one to six weeks before they recover completely.
High-Risk Groups and Potential Complications
Pregnant individuals, particularly in their second or third trimester, are especially vulnerable to hepatitis E. Infection during pregnancy can lead to fulminant hepatitis, a form of acute liver failure, which is associated with high rates of mortality. This severe outcome is most often linked to the HEV-1 genotype.
Another high-risk group includes individuals with compromised immune systems, such as organ transplant recipients or those with HIV. These individuals may be unable to clear the virus, leading to a chronic HEV infection. People with pre-existing chronic liver disease are also at a higher risk of developing acute-on-chronic liver failure if they contract HEV.
Diagnosis and Medical Management
Diagnosing a hepatitis E infection requires laboratory testing. The process involves blood tests to detect specific antibodies (immunoglobulin M and G) produced in response to the virus. Another method involves testing blood or stool samples for the virus’s genetic material, or HEV RNA. In immunocompromised patients, the HEV RNA test may be the only positive indicator of infection.
For most cases of acute hepatitis E in otherwise healthy individuals, there is no specific antiviral treatment. Management is supportive and focuses on rest, adequate nutrition, hydration, and avoiding substances that can harm the liver, like alcohol. In cases of chronic HEV infection, particularly in immunocompromised patients, antiviral medications such as ribavirin may be used to help clear the virus.