The World’s First Human Case of Rat Hepatitis E Was Detected in Hong Kong

The first known case of a human infected with a version of the hepatitis E virus carried by rats was confirmed in Hong Kong Thursday.

According to University of Hong Kong (HKU) researchers, it remains unclear how the patient contracted rat hepatitis E, a genetically distinct form of the virus that was previously isolated in rodents.

The patient, a 56-year-old man, contracted a strain of hepatitis “highly divergent” from other strains affecting humans, the South China Morning Post reports. The man lives in a housing estate that had “evidence of rat infestation in the refuse bins,” according to HKU researchers.

“We postulate that contamination of food by infected rat droppings in the food supply is possible,” the researchers said. They also acknowledged that the virus’ transmission method remained unconfirmed.

An estimated 20 million people are infected with hepatitis E every year, according to the World Health Organization. The virus is a liver infection that can cause fever, abdominal pain and jaundice. In rare cases, it can also cause liver failure and death. In most cases, the virus is spread through contaminated water.

Previously, there was no evidence that rat hepatitis E, a variants of the virus affecting mammals, was transmittable to humans.