Which animals wear mpox? Our study identified forest-dwelling African rodents as one source

Mpox is a disease caused by the highly contagious monkeypox virus. It is passed on quite easily from one person to another. But it originally came from infected animals.

The virus was discovered in 1958 when two outbreaks of smallpox-like infections were observed in monkeys shipped from Singapore to Denmark for research. Studies However, it has since been shown that monkeys are not the natural host (reservoir) of the virus. This idea was dropped in the 1970s when human cases were observed in West and Central Africa. A large-scale one in 1979 questionnaire from 43 animal species revealed further evidence of exposure to the virus.

It is not yet certain which animals are the natural carriers. But based on what is available proofThey are thought to be rodents and small mammals found mainly in West and Central Africa. Rodents first entered the mix when the 1979 evidence implicated at least one species of terrestrial rodent, and even more prominently, squirrels. Have further information shown that about 12% of people thought to have been infected through contact with animals had recent contact with squirrels.

I am a veterinarian and virologist research in this area. I keep a close eye on new developments and studies that fill missing gaps in our knowledge of virus transmission from animals to humans.

In recent research in which I was involved, we found evidence of orthopoxvirus infections in a genus of mice (Praomys And Mus) and the black rat. Orthopoxvirus is a genus of viruses that cause smallpox, cowpox, horsepox, camelpox and mpox.

A brief history

The first reported human case of MPox was with a nine-year-old boy in Zaire (now the Democratic Republic of Congo or DRC) in 1970. This was during the drive to vaccinate people against smallpox. After smallpox was eradicated in 1980, people stopped being vaccinated – and the number of MPox cases increased. But people have been vaccinated against smallpox were protected from mpox.

Major outbreaks of MPOX occurred in the DRC between 1996 and 1997, and sporadic cases occurred in other African countries in the following decades.

There have been cases reported in Benin, Cameroon, Central African Republic, Gabon, Ivory Coast, Liberia, Nigeria, Republic of Congo, Sierra Leone and South Sudan.

Epicenter of Mpox

Mpox found in nature is usually confined to the humid forest areas of West and Central Africa. Continued reporting of cases has been largely limited to the DRC in Central Africa and most recently Nigeria in West Africa.

There are two clades (natural groups) of the mpox virus and a subdivision of clade II (IIa). Clade I, the clade of the Congo Basin, is deadlier and more transmissible than clade II, the West African clade. Both are possible found in Cameroonwhich is geographically a division between the Central and West African countries.

In Cameroon the Sanaga River appears to form a natural barrier between the two clades.

Tracing the animals involved

Evidence about the virus and the spread of disease indicates that animals may be a reservoir of the mpox virus. In the DRC there are 43 animal species, including primates shown positive evidence of exposure to orthopoxvirus. At least one species of land rodents, especially squirrels, do shown antibodies specific to the virus that causes mpox – in other words, they have been exposed to the virus.

In another research About 12% of people thought to be infected had also had contact with animals, especially squirrels. There was also evidence of antibodies against orthopoxvirus detected in vervet monkeys in Ivory Coast.

Early association of the mpox virus with disease in primates such as the genus Macaca led to the suspicion that it could be a primate pathogen of East or South Asian origin. Later identification However, several human infections in remote African villages changed this idea. This ruled out East or South Asia as an origin.

Because many of the first humans were infected with mpox exposed to primatesPrimates were initially thought to be the main source and largely responsible for transmitting the infection to humans. But now more species of animals appear to be the route for transmission to humans.

It has also been suggested that farming creates habitats suitable for squirrels and for African possums, which is common during harvest times. These rodents probably had contact with peopleleading to virus transmission.

Three genera of African rodents, Grafius (African dormice), Cricetomies (giant possum) and Funisciurus (African striped squirrel), have been named as probable reservoirs of the mpox virus.

The first time that virus was found in a wild animal was in 1985 when a squirrel (Funiscirurs anerythrus) with mpox symptoms was recorded in what was then Zaire.

In one recent study that we conducted in Nigeria, we found evidence of orthopox in mice and black rats. This means that other rodent species could be a reservoir for the mpox virus.

The potential for the mpox virus to spread among household members is lower than the potential of smallpox.

We therefore assume that mpox is maintained in endemic areas by the reintroduction of the virus animals for people.

Transmission to humans is mainly associated with rainforest habitat. This supports the idea that it comes from rodents that live in the forest.

One form of contact could be bushmeat hunting. The suspected reservoir rodents love it Cricetomies And Funisciurus It is widely hunted for food by people in rural communities.

People can also become infected if they are bitten or scratched by animals. Or by handling an infected animal or animal products. Eating undercooked meat and other products from infected animals is another possible risk factor.

Protective measures

Mpox prevention requires strict adherence to biosecurity and personal hygiene. Biosafety means preventing pathogens from entering or leaving a place where they could pose a risk to animals, people or the safety and quality of a food product.

Raising awareness of risk factors such as contact and handling with wildlife and bushmeat can reduce exposure, especially in forested rural areas.

This article is republished from The conversationan independent, nonprofit news organization that brings you facts and trusted analysis to help you understand our complex world. It was written by: Clemens Meseko, National Veterinary Research Institute, Vom, Jos

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Clement Meseko receives funding from the National Veterinary Research Institute. He is partly affiliated as a WOAH/FAO expert on animal influenza. He is also co-principal investigator of the (GHPP) Global Health Protection Project grant, Germany.