Monkeypox outbreak: Genetic mutation may be driving rapid spread of virus, says WHO

The World Health Organization told AFP on Wednesday that studies are underway to see whether genetic changes in the monkeypox virus are driving the rapid spread of the disease.

The two distinct groups, or variants, of the virus, were called the Congo Basin (Central African) and West African clades, after two regions where they are each endemic.

On Friday, the WHO renamed the groups to Clade I and Clade II, respectively, to avoid the risk of geographic stigma. It also announced that Clade II had two subclades, IIa and IIb, with the latter virus being identified as behind the current global outbreak. On Wednesday, the United Nations health agency specified that clades IIa and IIb are related and share a recent common ancestor – so IIb is not a branch of IIa. Research into the mutation includes viruses collected in the 1970s and in clade IIb since 2017.

“Looking at the genome, there are actually some genetic differences between the viruses in the current outbreak and the older clade IIb viruses,” the WHO told AFP. “However, nothing is known about the significance of these genetic changes, and research is ongoing to establish the effects (if any) of these mutations on transmission and disease severity.” It is too early to tell whether the increase in infection may be driven by the observed genotypic changes in the virus, or is due to host (human) factors.”

There is no information yet about what the mutation means in terms of how the virus interacts with the human immune response. An increase in monkeypox infections has been reported outside endemic African countries since early May. The WHO declared the situation an international public health emergency on 23 July. More than 35,000 cases and 12 deaths in 92 countries have now been reported to WHO.

Almost all new cases are coming from Europe and America. Experts are studying samples of cases. “The diversity among the viruses responsible for the current outbreak is minimal, and there is no clear genotypic difference between viruses from non-endemic countries,” the WHO said.

Monkeypox’s name change could take months, meanwhile, the WHO said its campaign to rename Monkeypox could take “several months”. The organization has expressed concerns about the name for weeks, with concerned experts saying it is misleading. Monkeypox got its name because the virus was originally identified in 1958 in monkeys kept for research in Denmark.

However, the disease is found most frequently in rodents, and current outbreaks are spreading through human-to-human close contact.