First case in China! A 53-year-old man died of monkey B virus infection

On July 16, 2021, the China CDC Weekly reported the first case of human infection with monkey B virus in my country.

According to the weekly report of China Center for Disease Control and Prevention:

The patient is a 53-year-old male veterinarian who works at an institution in Beijing that specializes in nonhuman primate breeding and experimental research.

The patient dissected two dead monkeys on March 4 and 6, 2021, and developed symptoms of nausea and vomiting a month later, followed by fever and neurological symptoms. The patient visited several hospitals and eventually died on May 27.

Before this, there had been no reported cases of death from monkey B virus infection in my country, and no obvious cases of monkey B virus infection had been found clinically.

Through next-generation sequencing and real-time polymerase chain reaction, researchers confirmed that this was the first case of human infection with monkey B virus in China.

1. What is simian B virus?

According to a July 16 report in the China CDC Weekly, simian B virus was first isolated in 1932 and is an endemic alphaherpesvirus in macaques that is usually transmitted horizontally through direct contact and exchange of body secretions.

Simian B virus is not evident in its natural host, macaques, but approximately 60 cases of pathogenic zoonotic simian B virus infection have occurred sporadically, with a mortality rate of 70%-80%.

According to the article "A Brief Analysis of the Lethality of Monkey B Virus in Humans" published in the Journal of Comparative Medicine in China in 2017, Monkey B virus is the most potentially dangerous zoonotic virus carried by non-human primates, which can cause severe infectious diseases shared by humans and monkeys. Previously, cases of human infection with Monkey B virus have been reported in Europe and the United States, and there has also been a case of "human-to-human transmission".

2. How is simian B virus transmitted?

According to the above-mentioned article "A Brief Analysis of the Lethality of Monkey B Virus in Humans", Monkey B virus can lurk for a long time in the ganglia and tissues near the monkey's upper respiratory tract or urogenital organs, and excrete toxins intermittently through saliva, urine and genital secretions.

Monkey B virus is mainly transmitted directly between monkeys through mating, bites or scratches, and infected saliva through damaged skin or mucous membranes. It can also be transmitted indirectly through fomites.

Under the influence of certain environmental and social factors, the monkey B virus can cross the species barrier and infect humans. The monkey B virus causes human infection through monkey scratches, bites, needle punctures, cage scrapes and mucus splashes.

Previously, zoonotic simian B virus infections were primarily among primate veterinarians, animal care workers, or laboratory researchers in North America.

According to the article "A Brief Analysis of the Lethality of Monkey B Virus in Humans" published above, between the 1940s and 1950s, due to scientific research, the number of non-human primates introduced into Europe and the United States continued to increase, and the non-human primates introduced mainly came from wild animals captured in natural habitats. The pathogens carried by these non-human primates led to the outbreak of epidemic diseases, and cases of monkey B virus infection in humans began to appear. The infection generally occurred in the relevant scientific researchers and breeders who operated rhesus monkey experiments.

Therefore, the capture and introduction of wild non-human primates and scientific experimental research are factors that may increase the chance of contact between humans and the natural hosts of simian B virus, thereby triggering the host transfer of simian B virus.

3. What are the symptoms of infection with simian B virus?

If you have recently come into contact with monkeys or other primates, how can you tell if you are infected? What are the symptoms?

According to the above-mentioned article "A Brief Analysis of the Lethality of Monkey B Virus in Humans", when monkey B virus infects its natural host, rhesus monkeys, it does not cause obvious clinical symptoms. The characteristic symptoms of monkeys after infection are small blisters on the back of the tongue and the lips where the oral mucosa and skin meet, as well as other parts of the mouth. The blisters then rupture and form ulcers with fibrinous exudates on the surface, and then scabs form, which usually heal themselves in 7-14 days without leaving scars.

The typical symptoms of human infection with simian B virus are cold-like symptoms 1-3 days after exposure, with blister lesions at the site of exposure, accompanied by fever, muscle pain, fatigue and headache. Other symptoms include lymphangitis, nausea, vomiting and abdominal pain. As the virus spreads, symptoms of infection also appear in the central or peripheral nervous system, including ataxia, hyperthermia, paralysis and agitation. The mortality rate of untreated infected people is as high as 80%, and survivors will also experience neurological sequelae and further deterioration of neurological function.

4. How should we deal with simian B virus?

Due to the widespread use of non-human primates in biomedical research (such as animal experiments using monkeys), the potential risk of humans being infected with simian B virus has become an important factor threatening human health.

In order to control the infection of simian B virus in humans, in addition to improving traditional detection methods, developing effective vaccines and antiviral drugs, etc., laboratory personnel and breeders who often come into contact with monkeys should also take the following five infection control measures:

(1) Conduct health monitoring and regular quarantine of rhesus monkeys;

(2) During screening, quarantine and experiments, animals should be properly maintained in accordance with animal welfare requirements;
(3) Provide technical training and biosafety education to laboratory personnel, improve safety measures as much as possible, properly handle and promptly report exposure and infection, and correctly use protective equipment;
(4) During the breeding process, if infection or suspected infection is found, isolation is required;
(5) There are also some supporting strategies, such as reducing human changes to the natural world.

Source: Health Times