Monkey B virus causes first human death in China; what it is and what are its symptoms

As the world grapples with the coronavirus pandemic, a new infection has been reported in China. A Beijing-based veterinary surgeon was infected with the virus after he dissected two dead monkeys in early March, according to China CDC Weekly. The 53-year-old male vet, who worked for an institution researching on non-human primates, showed early-onset symptoms of nausea and vomiting, a month after he dissected two dead monkeys in early March, the state-run Global Times reported on Saturday, citing English Platform of Chinese Centre for Disease Control and Prevention. The vet had sought treatment in several hospitals, and eventually died on 27 May, the report said. His close contacts are safe from it, for now, it added. It said that there were no fatal or even clinically evident BV infections in China before, thus the vet’s case marks the first human infection case with BV identified in China. Researchers had collected the cerebrospinal fluid of the veterinarian in April and identified him as positive for BV, yet samples of his close contacts suggested negative results for the virus. It is necessary to eliminate BV during the development of specific pathogen-free rhesus colonies and to strengthen surveillance in laboratory macaques and occupational workers in China, the report said. Here’s what we know about Monkey B virus so far:

• The Monkey B virus, or herpes B virus, is prevalent among macaque monkeys, but extremely rare — and often deadly — when it spreads to humans.
• The virus, initially isolated in 1932, is an alphaherpesvirus enzootic in macaques of the genus Macaca.
• Other primates, such as chimpanzees and capuchin monkeys, can become infected with the B virus and will frequently die from these infections. There have not been documented cases of such primates spreading the B virus except to macaques as per the US CDC
• It is caused by macaques, a genus of Old World monkeys that serve as the natural host. While the virus is transmitted by macaques, chimpanzees and capuchin monkeys can also become infected and die.
• B virus is also commonly referred to as herpes B, monkey B virus, herpesvirus simiae, and herpesvirus B.
• English Platform of Chinese Centre for Disease Control and Prevention suggested that BV in monkeys might pose a potential threat to occupational workers.

How is it transmitted?

• As per the US CDC, infections due to the B virus in humans are rare and occur as a result of exposure to either macaques or their secretions or tissues.
• The incubation period for infection in humans after an identified exposure is reported to range from 2 days to 5 weeks; most well-documented cases present 5–21 days after exposure.
• According to China CDC Weekly, the virus is generally transmitted via direct contact and exchange of bodily fluid secretions.

What are its symptoms?

• Initial symptoms of the virus include — fever, chills, muscle aches, fatigue, and rash-itchy wounds, among others. These initial symptoms usually develop around 1-3 weeks after exposure to the virus.
• Symptoms of the infection can include meningismus, nausea, vomiting, persistent headache, confusion, diplopia, dysphagia, dizziness, dysarthria, cranial nerve palsies, and ataxia. Seizures, hemiplegia, hemiparesis, ascending paralysis, respiratory failure, and coma more commonly occur later in the course of infection. Some patients have presented with symptoms within 48 h after exposure to the virus.
• In the later stage, the virus can lead to the loss of muscle coordination and neurological damage.

How dangerous is the virus?

• In humans, it tends to attack the central nervous system and cause inflammation to the brain, leading to a loss of consciousness, said Kentaro Iwata, an infectious disease expert at Kobe University in Tokyo told  Washington Post.
• It can be transmitted via direct contact and exchange of bodily secretions and has a fatality rate of 70 percent to 80 percent. If untreated, there’s about an 80 percent fatality rate.

How does one treat the virus? There are currently no vaccines that can protect you against B virus infection.

• If you are in a place where there are macaque monkeys, you should stay away from them so that you do not get bitten or scratched. You should not touch or feed monkeys.
• Laboratory workers, veterinarians, and others who may be exposed to monkeys or their specimens have a higher risk of getting the B virus.

With inputs from agencies