The Grapevine

First-Ever Human Case Of Rat Hepatitis E Found

The first-ever case of a person being infected by rat hepatitis E virus has been observed in a 56-year-old man as revealed by researchers from the University of Hong Kong (HKU). 

The case study was led by Professor Yuen Kwok- yung and Dr. Siddharth Sridhar from the HKU department of microbiology. It is set to be published in the journal Emerging Infectious Diseases in December 2018.

It was said to be a discovery of "major public health significance," since there have been no documented cases of the infection being spread from rats to human beings until now. "This study conclusively proves for the first time in the world that rat hepatitis E virus (HEV) can infect humans to cause clinical infection," the researchers stated.

Hepatitis, which is characterized by inflammation of the liver, can be caused by excessive alcohol consumption, autoimmune diseases, and certain medication. But viruses are said to be the most common cause around the world.

There are five types (namely A, B, C, D, and E) of viral hepatitis, which can be spread by various means such as food contamination, sexual intercourse, sharing needles, pregnancy, and childbirth.

Type E is mostly caused by contamination and very rarely by person-to-person transmission. According to the World Health Organization, there are an estimated 20 million HEV infections around the world each year.

The infected person will face a variety of symptoms like fever, nausea, discoloration of the eyes, dark urine, pale stools, and an enlarged liver. Studies have shown that organ transplant recipients are at highest risk of being infected since they have to take medications that weaken their immune system.

So it is not surprising that the patient from the new case underwent a liver transplant at the HKU teaching hospital, Queen Mary Hospital, back in 2017. He received abnormal results in his liver function tests later, which indicated that something was wrong.

It was after further testing when doctors found him to be carrying a species of hepatitis virus only found in rats until that point. It was described as being "highly divergent" from the strain seen among infected humans.

While he had noticed rodent droppings at Choi Wan Estate, his area of residence, the patient did not recall seeing any rats inside his home. However, there was "evidence of rat infestation in the refuse bins outside his home," according to the research team.

"We postulate that contamination of food by infected rat droppings in the food supply is possible," they added, stating that the route of transmission of the virus was not clearly established. The university has planned to hold a press briefing to elaborate and reveal other important details about the case.