Smallpox is not yet an emergency in the world, according to the WHO

Smallpox is not yet an emergency in the world, the World Health Organization said on June 25.

The decision is made if the outbreak of the smallpox-related disease continues to spread, affecting at least 4,100 people in 46 countries as of June 24th. That includes at least 201 cases in the US. These cases have been found in 25 states and the District of Columbia, according to the U.S. Centers for Disease Control and Prevention.

“Controlling the further spread of the outbreak requires intensive response efforts,” and the situation should be reassessed in a few weeks, the WHO Committee’s assessment of the outbreak said. said in the announcement.

A declaration of a health emergency would potentially facilitate treatment and vaccines for people infected or exposed to the virus. Some medications and vaccines that can help fight monkeypox are approved for use against monkeypox and can only be used against monkeypox with special permission.

The virus that causes monkeypox is named after its discovery in monkeys in 1958, although it is likely that the virus, which mainly infects rodents, is not a new threat. In Central Africa, where monkeypox is endemic, there have been sporadic outbreaks since researchers discovered the first human case in 1970. By 2017, there were several cases in West Africa. But most cases outside the continent were related to travelwith limited distribution to others (CH: 26.05.22).

“Monkeypox has been circulating in a number of African countries for decades and is neglected in terms of research, attention and funding,” WHO Director-General Tedras Gebreies said in a statement announcing the decision. “This should change not only for monkeypox, but also for other neglected diseases in low-income countries, as the world is once again reminded that health is an interconnected situation.”

Smallpox usually kills less than 10 percent of people who become infected. At least one person died in a global outbreak.

As the number of cases increases, researchers are working to decipher the genetic plan of the virus, hoping to find out if some viral mutations can explain why the virus quickly became entrenched in new locations.

Mutation tracking

The closest known relative of the version of the virus behind the global outbreak comes from Nigeria, hinting that the outbreak may have started there.

In the latest outbreak, scientists have found more viral changes than expected – a sign that the virus may have been circulating unnoticed among humans for some time, possibly since the outbreak of monkeypox in Nigeria in 2017-2018. Moreover, many of these mutations may be due to a group of enzymes known for their ability to fight viruses in the body.

Genetic analysis of smallpox viruses that participated in the global outbreak, from 15 people in seven countries shows that these viruses have an average of another 50 genetic settings than the versions that were distributed in 2018 and 2019, the researchers report on June 24 Natural medicine. This is about 6-12 times more mutations than scientists expected the virus to develop during that time. Unlike some other types of viruses, poxviruses, which include smallpox and monkeypox viruses, usually mutate quite slowly.

The changes have a pattern that is a hallmark of a family of enzymes called APOBEC3, the researchers say. These enzymes edit the building blocks of DNA – represented by the letters G, C, A and T – in a certain way: Gs change in As and Cs in Ts. The analysis revealed this particular pattern in viral sequences, suggesting that APOBEC3 is responsible for the mutations.

Ideally, so many building blocks of DNA change into others that the virus is effectively destroyed and cannot infect more cells. But sometimes APOBEC3 enzymes do not make enough changes to kill the virus. Such mutated, though still functional, viruses can infect extra cells and possibly another person.

The big question, however, is whether the genetic changes observed in monkeypox virus are beneficial, harmful, or not affecting the virus at all.

It is not yet known whether enzymes are directly responsible for changes in monkeypox virus, similar mutations still appear, the team found. Thus, APOBEC3s can still help the virus change if it continues to spread. One member of the enzyme family is found in skin cells where humans with monkeypox can develop infectious smallpox lesions.

six images of different types of skin lesions caused by monkeypox
During the current outbreak, the skin lesions that can spread to monkeypox were less than in previous outbreaks. Here are some examples.UK Health Agency

Different symptoms

The symptoms reported during the global outbreak were generally milder than in previous outbreaks, which may have allowed the disease to spread before the person learned they were infected.

It is unclear whether these differences in symptoms are related to changes in the virus, said June 21 Inger Damon, director of the Department of Pathogens and Pathologies with High CDC Implications. news briefing organized by SciLine, a service for journalists and scientists sponsored by the American Association for the Advancement of Science.

Typically, previous outbreaks have shown people to have flu-like symptoms, including fever, headaches, muscle aches, and exhaustion about a week or two after contact with the virus. Then, one to three days after the onset of these symptoms, a rash appears that includes large, pus-filled lesions, usually starting from the face and limbs, especially on the hands, and spreading throughout the body. Although these symptoms are generally milder, these symptoms are similar to smallpox, but people with monkeypox also tend to have enlarged lymph nodes.

Damon said all patients in the U.S. epidemic got a rash, “but the lesions were scattered or localized to a specific area of ​​the body, not diffuse, and usually did not cover the face or … the palms of the hands or the soles of the feet. legs “. Instead, rashes can begin in the genital area or anus, where they can be mistaken for sexually transmitted diseases such as syphilis or herpes, she said.

In many cases, the rash does not spread to other parts of the body. And classic early symptoms, such as fever, were “mild and sometimes didn’t exist at all before the rash appeared,” Damon said.

Smallpox is transmitted from person to person through close skin-to-skin contact or through contact with infected towels, clothing or bedding. It can also spread through droplets of saliva, which are exchanged during kisses or other intimate contacts. The CDC is investigating whether the virus can spread through semen as well as skin-to-skin contact during sex, U.S. Health Service Captain Agam Rao said June 23 at a meeting of the CDC’s Immunization Practices Advisory Committee. .

“We have no reason to suspect that it is spreading by other means,” for example, by air, Rao said.

In Nigeria, more cases of monkeypox have been reported among women, while the global outbreak has affected mainly men, especially men who have sex with men. Experts warn that smallpox can infect anyone, and some people face an increased risk of serious illness. The high-risk group includes children, people with weakened immune systems, pregnant people and people with eczema.

The risk of contracting monkeypox through casual contact is still low in the United States, Rao said. But the data she provided show that while people in the country became infected with monkeypox while traveling abroad, the cases also spread locally.

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