An employee of the Bavarian vaccine company Nordic displays a container containing fibroblast cells from chicken embryos for breeding the vaccine virus in the company’s laboratory in Martinsried near Munich, Germany, May 24, 2018. 2022. The company, headquartered in Denmark, is the only one in the world that has approved a smallpox vaccine called Jynneos in the US and Imvanex in Europe, which is also effective against smallpox in monkeys.
Lukas Barth | Reuters
monkeypox virus, has now been diagnosed in hundreds of people in 26 countries, may have been quietly circulating for years before it suddenly appeared worldwide, some scientists speculate.
Infectious disease experts and scientists in genetics laboratories are urgently searching for clues to why a virus has been found in West Africa for half a century and is usually not contagious. spread from person to person appeared so dramatic and disturbing in the past months.
“It is possible that there has been undetected transmission for a long time,” said Dr. Rosamund Lewis, the World Health Organization’s technical lead on monkeypox. “What we don’t know is how long it might have lasted. We don’t know if it’s weeks, months or maybe a few years.”
At the University of Leuven in Belgium, virology professor Marc Van Ranst told NBC News that sequencing in his lab showed that the virus’s genetic mutations were “limited” and “none of those” they are smoking guns.
“Everybody is interested in more complete genomes to get an idea of a rather important question: How long have these viruses been circulating, under its watch?” Van Ranst said. “I think no one believes this jumped out of Africa a few weeks ago. “
University of Edinburgh scientists recently sequenced samples from the outbreak and Post their findings on May 30. The samples they investigated were derived from a version of monkeypox that was identified in Singapore, Israel, Nigeria and the United Kingdom between 2017 and 2019.
Although investigators have identified an “unexpectedly large number” of changes to the virus’ genetic code since that time, some experts do not believe such changes necessarily solve the problem. like the current outbreak level.
In Africa, most human cases of smallpox have occurred historically from contact with infected animals such as rodents rather than from human-to-human transmission.
“What is likely to happen is that an endemic infectious disease from Africa makes its way into social and sexual networks and is then greatly aided by massive amplifying events like crazy in Belgium for worldwide dissemination,” said Dr. Amesh A. Adalja, a senior scholar at the Johns Hopkins Center for Health Security.
“And then,” added Adalja, “because it’s passed on close contact during sexual encountersMany lesions are mistaken for other STIs, which can delay diagnosis. “
The vigilance of public health authorities, healthcare providers and individuals worldwide has dramatically improved detection in recent weeks.
“Whenever you start looking for a new disease in a population, you find a lot of other cases,” said Dr. David Heymann, a professor at The London School of Hygiene and Tropical Medicine, who previously led the WHO Program on Infectious and Emerging Infectious Diseases, told NBC News.
Heymann supports the hypothesis that the disease may have been present in some populations for several years outside of the 11 Central and West African countries where the virus has become endemic. He suggested that cases could be circulating surreptitiously among people outside of the global gay community.
“The concern is only looking at one population group rather than the broader view,” he said.
Monkeypox symptoms are very mild
The infection, which can cause painful lesions all over the body with long-lasting scarring, will usually occur in an individual in about three weeks. Most of the cases identified in Europe and the US outbreaks are mild – some cases are so subtle that they are mistaken for other sexually transmitted infections – and have occurred among gay, bisexual and other men who have sex with men. However, experts stress that it is close physical contact during sexual activity that is the main factor driving disease transmission.
Unlike what is commonly seen in cases of monkeypox in Africa, some recent infections have resulted in “very, very mild” symptoms, perhaps involving only a single lesion, Dr. Sébastien Poulin, an infectious disease specialist at St-Jérome Hospital in Montréal ai diagnosed one of the first cases of the outbreak in Canada, told NBC News. “Doctors need to be aware of that.”
Add Doa, Monkeypox usually begins with a fever, but some recent cases in the US did not report fever or other early signs before the lesions appeared, according to the Centers for Disease Control and Prevention.
“For this reason, cases can be confused with more commonly seen infections such as varicella zoster or sexually transmitted diseases“such as genital herpes or syphilis, CDC study published on Friday reported.
Sixty-six people have died from the infection in African countries by 2022, according to the World Health Organization. Nigeria has been grappling with an outbreak of monkeypox since 2017 – an outbreak that may have served as a cradle for global spread.
There have been no deaths in the current outbreak in Europe or the US, although in the US at least one person has been hospitalized for severe pain from damage to the anus, Captain Jennifer McQuiston, deputy director of the High Consequences Pathogens Agency and Pathology Division at the CDC, said at a news conference Friday.
McQuiston acknowledged the possibility of missing previous cases of monkeypox virus in the US, but “not to any extent,” she said at the meeting. Two cases detected in the US in 2021 – an individual in Texas in July and a separate case in Maryland in November. Both had recently traveled to Nigeria.
Van Ranst said the coming days of the outbreak will be crucial for disease control. As of June 1, there were 643 confirmed cases, according to WHO. If by next week the number of cases accumulates on an exponential curve and hits perhaps 4,000, “then this is out of control,” he said.
If the number only grows to about 1,000 instead, the outbreak is likely to only expand linearly, which bodes well for global control of the virus, Van Ranst said.
