First case of rat hepatitis in a human documented in Hong Kong

Perhaps the only positive thing that can be said about rat hepatitis E is that it belongs to rats, and we humans don’t have to deal with it.

At least, that’s what we thought. The scientific and medical perspective of the disease has now been shattered after a man in Hong Kong was found to have contracted the virus, the first known example of transmission to humans.

The University of Hong Kong confirmed the 56-year-old’s diagnosis.

“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 the university’s Dr. Siddharth Sridhar. He noted that diseases that cannot be transferred to monkeys usually cannot be transmitted to humans, either.

Experts believe the man was probably infected thanks to a rat infestation in a garbage chute near his home. His doctors realized he had the disease after treatment for an already chronic case of hepatitis B. He received a liver transplant but continued to show signs of abnormal liver function. Doctors weren’t sure why.

They investigated and found signs of an immune response to human hepatitis E, but more detailed tests came back negative. Investigators had to resort to genomic sequencing, looking at the entire DNA (or genome) of the virus to see what it really was.

The verdict? No human illnesses — rat hepatitis E.

The patient is fine now, having received antiviral treatment. An expert told CNN that it was unlikely that the patient would have been able to transmit the virus to other humans, and that he likely only contracted the virus because his immune system was compromised by his recent surgery.

Experts are saying that rodent control is key to preventing the spread of any rat disease to humans, and that prompt and proper disposal of trash can make it a lot harder for rats to hang around.