Two cases of monkeypox in India unrelated to Europe

Genome sequencing of the first two imported cases of monkeypox detected in Kerala clearly shows that they belong to a small cluster, A2. Over 75 countries. Genomes from outbreaks of large monkeypox cases in Europe and elsewhere belong to the B1 lineage.

The viral genomes collected from the first two cases in Kerala were sequenced by ICMR’s Nodal Lab, National Institute of Virology (Pune) and deposited in the global database GISAID without delay.

two different outbreaks

In the first week of June, the CDC found that 3 out of 10 genomes sequenced from viruses collected in the US differed from viruses sequenced in Europe. Genetic sequencing of the monkeypox cases strongly suggested that he had two different monkeypox outbreaks outside of endemic countries in Africa. Two different clusters indicated that human-to-human transmission outside Africa occurred for a longer period of time than originally assumed. A smaller cluster, mainly found in the United States, Thailand, and now India, is the A2 cluster.

All three imported cases detected in Kerala were males arriving from the Middle East. write in statistics, Helen Branswell pointed out that three genomes from viruses belonging to the A2 cluster collected in the United States are from infected people from different parts of the globe. Middle East or East Africa.

Based on the widespread geographic spread of viruses belonging to the A2 cluster, Inger Damon, director of the CDC’s Division of High Outcome Pathogens and Pathology, said: statistics The virus has been quietly spreading outside endemic countries for a long time.

All three imported cases detected in Kerala were persons arriving from the Middle East, but some of the cases detected elsewhere and classified in this cluster had a history of travel to the Middle East or East Africa. belongs to the people.

Super Spreader Event

The outbreak, which began in Europe in early May of this year and spread primarily through human-to-human transmission, has now grown to more than 21,000 cases worldwide. Persistent transmission among humans was primarily among men who have sex with men (MSM), and two superspreader events spread across Europe in a matter of days. It is quite different from the large B1 cluster, which represents a virus that has started to spread.

According to Dr. Vinod Scaria, a senior scientist at the Delhi-based Institute for Genomics and Integrative Biology (CSIR-IGIB), a small A2 cluster containing a very small number of genomes dating back to July 2021 is believed to have been infected by other viruses. It shows no signs of spreading. Super spreader event.

“The earliest sample of the cluster from the United States is indeed from 2021, suggesting the virus has been circulating for quite some time and earlier than the European event,” said Dr. Scalia. . murmured.

“A2 appears to have a very distinct origin and has nothing to do with the outbreak in Europe,” Dr. Scalia said. hindu“The A2 cluster has a long tail, suggesting that it originated long ago. Viruses belonging to the A2 cluster probably spread silently. But there is no intermediate genome.” [sequenced at regular and short intervals between July 2021 and early June 2022] However, it is available. ”

Given that the A2 clusters found in the United States and now India are very small, with only a handful of genomes, it is possible that the spread of viruses belonging to the A2 cluster was absent in MSM networks. The B1 lineage is mainly found in MSM networks. It is based on the premise that if the A2 cluster was also found in the MSM network, the number and geographical spread of virus-infected people in the A2 cluster were comparable to the B1 lineage.

However, Dr. Scalia cautions against drawing such conclusions based on the few samples that have been sequenced. “The A2 cluster may have been found in he MSM networks, but it would not have spread as widely as the B1 lineage because there are no superspreader events,” he says. “It’s too early to draw any conclusions because the genome sequence doesn’t provide enough information.”

US leads in cases

As of July 28, 4,907 monkeypox cases It has been detected in the United States, by far the most in any country.and 37 European countries fully 13,043 reports Monkeypox as of July 26th.

Based on results from a UK case series published in BMJMore As of July 28, nearly 99% of cases were confined to MSM networks, with sexual contact with an infected person being the main driver of virus spread. And a significant percentage of cases are her HIV-positive.

“At the moment the outbreak is concentrated in MSM, but as the number of cases rises, we will see cases in other demographic groups. There have also been relatively few cases in children and women. This is why it is so important to act quickly to contain this,” tweeted Dr. Boghuma Titanji of Emory University School of Medicine in Atlanta. There have been no examples of spread of infection among people.

Claiming the fact that the monkeypox virus is less contagious than the SARS-CoV-2 virus and requires close and intimate contact to spread from person to person, the UCL Institute of Genetics Dr. François Baroux tweeted that the virus can only be maintained. As such in demographics where people have many sexual partners, such as the MSM network.

“The monkeypox virus is not a potential STD among heterosexuals. Because you can get rid of it and essentially get immunity for life. murmured.

But Dr. Titangye disagrees. He said, “I do not agree that sexual transmission cannot occur among heterosexuals. It certainly can and probably has.

increased risk

Scientists debate whether and to what extent the virus can spread among heterosexuals, but it is likely that the virus will continue to circulate longer and infect more people. , it is abundantly clear that viruses become more contagious and acquire the ability to evolve and spread. Easier with multiple routes.