【Smart Farmers】What do we need to know about monkeypox?

Monkeypox is a viral zoonotic infectious disease caused by the monkeypox virus. As the name suggests, monkeys, non-human primates, rodents, humans, etc. can be infected and can be transmitted to each other.

Since 2017, cases of monkeypox have been reported in many parts of the world. On November 1, 2022, the World Health Organization issued a statement stating that the monkeypox epidemic continues to constitute an "emergency public health event of international concern."

What is monkeypox?

In 1958, a mysterious disease with skin blisters as the main symptom broke out among monkeys shipped from Africa to Copenhagen, Denmark. People extracted a new virus from the sick monkeys and named it monkeypox virus. Subsequent studies found that the monkeypox virus (MPXV) is a member of the genus Orthopoxvirus in the family Poxviridae.

In August 1970, a 9-year-old child in the Democratic Republic of Congo developed smallpox-like symptoms and was later confirmed to be infected with the monkeypox virus by laboratory tests. This was the first documented case of human infection with the monkeypox virus in the world.

Monkeypox virus morphology (picture from the Internet)

How is monkeypox spread?

Although it is called "monkeypox", the most likely natural host of the virus is rodents. Primates (including monkeys, chimpanzees, humans, etc.) can also become sources of infection after infection.

Host of monkeypox virus (picture from the Internet)

Monkeypox virus can be transmitted between humans and animals through direct contact with the blood, body fluids or skin lesions of infected animals, or by scratches from infected rodents, small mammals and other wild animals. The transmission rate of monkeypox virus between humans is lower, and it can be transmitted through close contact with the respiratory secretions, body fluids or skin lesions of infected people, and it is also possible to be infected by contact with objects contaminated with the virus. The virus can also be transmitted from a pregnant woman to her fetus through the placenta.

What symptoms will occur after infection with monkeypox virus?

The main symptoms of monkeypox infection in animals include lethargy, loss of appetite, coughing, fever, red and swollen eyelids, increased eye discharge, and swollen lymph nodes, which may be accompanied by a plaque-like or vesicular rash. Rodents are sensitive to the virus and have a high mortality rate.

Macaques infected with monkeypox (Photo from the Internet)

The symptoms of monkeypox virus infection in humans are similar to those of smallpox virus infection, but monkeypox patients have swollen lymph nodes and the disease is milder. The incubation period of monkeypox is 5-21 days, usually 6-13 days. Initially, mild flu-like symptoms such as headache, fever, muscle aches and fatigue appear. A rash appears on the face a few days after the disease develops, and then the rash spreads to other parts of the body, mainly the limbs, with the palms and soles of the feet often affected.

Monkeypox is a self-limiting disease that usually lasts 2-4 weeks before full recovery, and most cases have a good prognosis. Severe cases are common in young children or immunocompromised people, and the prognosis is related to the infected virus branch, the degree of virus exposure, health status, and the severity of complications.

Symptoms of monkeypox infection in humans (picture from the Internet)

How to prevent and treat monkeypox?

For monkeypox, since there is currently no effective treatment, the general prevention measure is to avoid contact with animals that carry the virus.

The number of monkeypox cases has surged in West and Central Africa since 2019, but it did not receive widespread attention until this year when it spread globally.

In June and September 2022, the first cases of monkeypox infection were imported into Taiwan and Hong Kong, respectively; on September 19, 2022, the first imported case of monkeypox was detected in Chongqing, my country.

In order to understand the situation of monkeypox virus in artificially bred primates and rodents in Guangdong Province and provide reference data for the prevention and control strategy of monkeypox virus, in October 2022, the zoonosis research team of the Animal Health Institute of Guangdong Academy of Agricultural Sciences collected a total of 505 primate and rodent samples from 20 wildlife rescue centers or zoos in 14 prefecture-level cities in Guangdong Province. According to the "Technical Guidelines for Monkeypox Prevention and Control (2022 Edition)" issued by the National Health Commission, monkeypox virus (MPXV) was detected using fluorescent quantitative PCR method. The results showed that there are currently no animals infected with monkeypox virus in Guangdong Province.

However, the risk of monkeypox virus being imported into my country will continue to exist. As the epidemic emerges in Europe and the United States, the risk of imported cases in my country will also increase accordingly.

People entering and leaving the country should raise their awareness of risks and take good personal protection measures. They can take the following measures to reduce the risk of infection:

① In areas where there is a risk of monkeypox transmission, avoid any contact with primates and rodents that may be infected or with patients infected with monkeypox virus;

②In daily life, strengthen exercise to improve immunity, pay attention to personal hygiene, wash hands frequently, ventilate frequently, disinfect regularly, and cook meat thoroughly before eating;

③ Wear a mask when you go to crowded places;

④ If you find any symptoms related to monkeypox, you should seek medical attention immediately and cooperate with self-isolation.

Author: Li Na (graduate student at the Institute of Animal Health, Guangdong Academy of Agricultural Sciences)

Scientific review: Wang Xiaohu (Director and researcher of the Zoonoses Department, Institute of Animal Health, Guangdong Academy of Agricultural Sciences)