Is Hepatitis E Sexually Transmitted?

Hepatitis E is a water-borne pathogen basically transmitted by drinking contaminated water and is not thought to be sexually transmitted. There is no scientific proof that HEV spreads from sexual contact. HEV is different from other virus, which won’t even spread from person to person (for example by shaking hands). Most of the other Hepatitis virus (A, B, and C) transmitted through sexual contact. But there is a difference between them how they transmit and risk exposure during sexual contact.

Hepatitis E is undoubtedly transmitted through the fecal-oral route. It is frequent in countries where clean water lacks and poor sanitation. People from high-income countries may get HEV infection through the contaminated water while traveling in the endemic countries. These travel infections are mainly associated with genotypes 1 and 2. However, there are reported cases of patients who have not traveled to endemic countries. This condition is referred to as autochthonous hepatitis infections, which have increased recently in developed countries.

Autochthonous hepatitis infections are mainly caused by HEV genotype 3, symptomatic HEV genotype 3 infections are more common among middle-aged and older individuals as well as among men. HEV infections are usually asymptomatic, but genotype 3 infections may cause chronic hepatitis in immunocompromised patients. This group includes patients who have received an organ transplant, the patients receiving chemotherapy and HIV-infected individuals. The most recent evidence suggests that HEV caused by genotypes 3 is transmitted zoonotically.

Outbreaks of hepatitis E have occurred in many south-east Asian countries, Africa and Mexico, as well as in other geographical areas lacking a clean water source and sanitation. The incidence of this virus was first reported in 1955 during an outbreak in New Delhi, India. It was the epidemic in the year 1955–56 outbreak in Delhi, affecting a total of 29000 people. Transmission routes continue to be one of the most debated aspects of HEV. However, no strong conclusions can be drawn about sexual transmission of HEV.

Another fact is the virus has a 50% rate of vertical transmission. A vertically transmitted infection means mother-to-child transmission i.e. directly from the mother to an embryo or during pregnancy or childbirth. There is increasing evidence that HEV is an important contributor to maternal morbidity and mortality in South Asia, especially if infection occurs in the third trimester with genotype 1. It causes fulminant hepatic failure and maternal death which the mechanism (pathogenesis of liver injury) is unclear. But some theories say that interplay of hormonal and immunologic changes during pregnancy, along with a high viral load of HEV, renders the woman more vulnerable.
Immunologic changes during pregnancy promote the maintenance of the fetus in the maternal environment by suppression of T cell-mediated immunity, rendering pregnant women more susceptible to viral infections like HEV infection. During pregnancy, levels of progesterone, estrogen, and human chorionic gonadotropin increase as pregnancy advances. These hormones play a considerable role in altering immune regulation and increasing viral replications.

To reduce the infection, it is important to maintain hygienic practices such as hand washing with safe water, particularly before handling food, avoiding drinking water or using ice cubes of unknown purity, and avoiding eating unpeeled fruits and vegetables. At present, the treatment options for patients with chronic hepatitis E include reduction of immunosuppression and administration of pegylated interferon alfa or ribavirin. Currently, there is no HEV vaccine available except in China. This vaccine is not sold in other countries as it is not approved.

Vaccination, sanitization of sewage and water sources, and public education will help to prevent endemics or epidemics, which can end in lowering the human burden. The development of a vaccine against the zoonotic swine HEV would reduce food borne and swine contact cases in humans as well as diminish the spread of the virus between animal species. Control of animal waste, run-off, and decontaminated sewage is key to limiting the spread of HEV to coastal and surface waters and in turn reducing concomitant contamination of shellfish.

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Is Hepatitis E Sexually Transmitted?