A veterinary surgeon in China has died after dissecting two monkeys and becoming infected with monkey B virus (not to be confused with monkeypox, which has recently been documented in America).
The Chinese Center for Disease Control and Prevention (CDC) reports that the 53-year-old man worked at a lab in Beijing specializing in nonhuman primate breeding and experimental research. The researcher dissected two dead monkeys in early March 2021, and started to experience nausea and vomiting followed by a fever and neurological symptoms one month later.
After several stays in hospital, he eventually died on May 27. Two of his close contacts, a doctor and a nurse, tested negative for the virus.
Monkey B virus (aka B virus, Macacine herpesvirus 1, or McHV-1) is a rare but fascinating virus. It typically infects macaque monkeys and is genetically very similar to herpes simplex virus 1 (HSV-1), the ubiquitous virus that causes cold sores in humans. Just like HSV-1, it’s a neurotropic virus that is capable of infecting nerve cells. When it infects macaques, the B virus causes cold sore-like lesions. However, when humans are zoonotically infected with monkey B virus, it can cause severe inflammation of the brain, resulting in permanent neurological dysfunction or death.
This recent case in Beijing is China's first reported fatal case of a monkey B virus infection. Since it was first described in 1932, around 50 people have been documented to have infections; 21 of whom died, according to the US Center for Disease Control and Prevention.
In 1997, 22-year-old researcher Elizabeth Griffin was working with infected macaques at the Yerkes National Primate Research Center in Atlanta when one of the monkeys flung a tiny drop of fluid into her eye. Six weeks later, she died of complications from an infection caused by monkey B virus.
As this suggests, the virus can be transmitted from macaque to humans through contact with their saliva, poop, urine, and brain tissue. Lab workers, zookeepers, and veterinarians working with macaques are most at risk of infection – although hundreds of people are scratched by monkeys in the US each year and infections remain extremely rare, the US CDC notes.
Researchers are, however, becoming increasingly aware that wild free-roaming macaques can be infected with monkey b virus and they could potentially expose people to the infection. In 2018, a case report found that as many as 30 percent of monkeys living in and around Florida's Silver Springs State Park could be infected with the virus.
Fortunately, there has only ever been one reported case of an infected person spreading B virus to another person. In this case, reported in 1990, three people became infected with the virus at a research facility in Florida. A fourth person, with no direct connection to the lab, then became infected seemingly after rubbing in some skin cream that had been accidentally contaminated with the virus by one of the three infected people.