Director General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus has declared the monkeypox outbreak an international public health emergency. According to WHO, a dangerous viral infection has been detected in 75 countries and territories of the world, more than 16 thousand cases of infection and five deaths have been recorded. Most infections are still detected in Europe and America, mainly among men.
Mutates surprisingly fast
A Portuguese study published in the journal Nature Medicine offers the most insightful insight into the genetic material of a virus to date. monkeypox. The researchers took samples from 15 patients and compared the genomes of the virus that infected them. The monkeypox strain from Nigeria was found in each of the patients, which led to the previous outbreak in 2018-2019 in the UK, Israel and Singapore.
But tests have shown that since the previous outbreak, the virus has mutated 50 times – 12 times more than would have been expected. “These data completely refute what is known about the rate of mutation of the monkeypox virus,” said study author João Paulo Gomes of the Portuguese National Institute of Health.
West African monkeypox has lower mortality rate
New monkeypox genome sequencing has helped researchers better understand the current outbreak. The virus strain that led to it belongs to the West African clade of monkeypox, which occurs in western Cameroon and Sierra Leone and is characterized by mortality rate less than 1 percent.
A clade (variety) is a group of organisms in which common ancestors or a common genetic lineage can be traced. There is another common clade of monkeypox known as Central African, which is more common in the Congo Basin and has a mortality rate of up to 10 percent.
Monkeypox incubation period difficult to track
The incubation period of the disease ranges from five to 21 days, making it difficult distribution tracking. The WHO has identified Patient Zero, the first confirmed case identified in a person who traveled from Nigeria to the US in early May. But the Portuguese researchers disagree with the WHO. According to them, cases of the disease were confirmed in Portugal and the UK as early as the end of April.
Scientists point to a highly probable fact that the virus could have been imported from a country where monkeypox endemic, for example, from Nigeria, but other possibilities cannot be ruled out. For example, that after the 2018-2019 outbreak, the virus quietly spread through humans or animals in countries where it is not endemic, such as the UK or Singapore.
At the same time, according to them, it is not clear whether the mutated version is more dangerous than the original one. “The authors describe an unexpectedly high number of mutations in the virus, but their implications for disease severity or ability to infect are not clear,” said Hugh Adler of the Liverpool School of Tropical Medicine, who was not involved in the Portuguese study, commenting on the article.
“We found no change in clinical severity in patients diagnosed during the current outbreak,” added Adler, who has worked with monkeypox patients in the UK during previous outbreaks.
Transmitted primarily through sexual contact
Scientists at Queen Mary University of London studied 528 confirmed cases of monkeypox virus infection in 16 countries between April 27 and June 24, 2022. According to a study published in the New England Journal of Medicine, 98 percent of those infected were gay or bisexual men, and 41 percent had HIV. Their average age was 38 years. The average number of sexual partners in the previous three months was five, and about a third of them attended sex parties or saunas during this period.
The study also showed that monkeys with smallpox experienced symptoms not previously associated with the virus, such as sporadic genital lesions and ulcers in the mouth or anus. Many of them are similar to the symptoms sexually transmitted diseases, which could lead to misdiagnosis, the researchers warn.
“It is important to emphasize that monkeypox is not a sexually transmitted infection in the traditional sense – it can be contracted through any close physical contact. However, our work shows that most cases of infection so far have been associated with sexual activity, mainly, but not exclusively among men who have sex with men,” said study leader John Thornhill. The scientists stressed that monkeypox can also be transmitted through contact with respiratory droplets or clothing emitted by a sick person.
“Most of the cases were mild with no fatalities. Although 13 percent of patients were hospitalized, most of them did not experience serious complications,” the study notes. Monkeypox DNA was found in the semen of 29 of the 32 individuals tested, but it is not yet clear whether semen is capable of transmitting the infection.
Monkeypox ignored for decades
In general, humanity lacks knowledge about monkeypox. The study of the genetics of this virus is “still in its infancy,” says Hugh Adler. “We have the genome sequence, so we have an idea of how the virus works. But in terms of understanding what its genes do, and what are the consequences for evolution if the genes change, there is very little research on this issue compared to others. viruses known to us,” the scientist admits.
The work of the Gomes group in Portugal has provided “exciting” new insights into the biology of monkeypox, he said, but he noted that the study only appears to have been carried out because of the spread of the virus in high-income countries. “If the world community applied the same scientific resources to monkeypox outbreaks in Africa, we might already have a larger knowledge base,” Adler said.
The WHO agrees with him. Monkeypox virus has been circulating in several African countries for decades, the organization says, and has been overlooked in terms of research and funding. The WHO Committee on Emergency Situations called for a change in this approach not only for monkeypox, but also for other “neglected diseases”. Recall that this infection was first detected in a monkey in 1958, and the first human case was detected in a small child in the Democratic Republic of the Congo in 1970.