A 56-year old man in Hong Kong has contracted the first human case of rat hepatitis E.
According to CNN, the patient developed the disease after a liver transplant in May, 2017. He continued to show abnormal liver functions with no obvious cause.
Further tests revealed signs of an immune response to hepatitis E. Tests for the human form of the virus, however, came back negative. Genetic sequencing of the virus eventually revealed similarities with the rat form of the disease, which is known to occur only in animals.
“Previous laboratory experiments have found that rat hepatitis E virus cannot be transmitted to monkeys, and human hepatitis A virus cannot be transmitted to rats,” said Siddharth Sridhar, from the University of Hong Kong.
The man is fortunately cured after given antiviral treatment. Doctors also said that they can no longer detect the virus in clinical specimen.
Sridhar and his colleagues, however, wanted to know how the disease was able to cross over from rodents into a human.
It is possible that the man contracted the illness through food contaminated by rat droppings. The man happens to live in a housing estate where there were signs of rat infestation outside of his home.
Rat hepatitis E virus is now included in the list of infections that can be possibly transmitted from rats to humans. Before the case, there had been no previous evidence that the virus could be transmitted to humans, albeit it is thought to infect other mammals, such as domestic pigs, wild boar, and deer.
The hepatitis E virus in humans is known to be transmitted through food or water that are contaminated with infected fecal matter. People can also get infected through blood transfusions from infected donors and eating uncooked or undercooked meat or organs of infected animals.
According to the CDC, most people with Hepatitis E can recover completely. The virus, however, can cause serious illness in pregnant women with mortality reaching between 10 to 30 percent in the third trimester of pregnancy. The illness could also be serious in individuals with preexisting chronic liver disease.
“Although rare in developed countries, locally acquired HEV infection can result in acute hepatitis with tendency to progress to chronic hepatitis mainly among solid organ transplant recipients,” the CDC said.
Good sanitation is recommended to prevent infection.
Experts said that transmission of rat hepatitis E virus to humans can be prevented by controlling the population of disease-carrying rats.