Studies to see if mutations behind monkeypox spread: WHO

GENEVA • Studies are under way to see whether genetic changes in the monkeypox virus are driving the rapid spread of the disease, the World Health Organisation (WHO) said on Wednesday as it called for people infected with monkeypox to avoid exposing animals to the virus, following a first reported case of human-to-dog transmission.

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

Last Friday, the WHO renamed the groupings as Clade I and Clade II respectively, to avert the risk of geographic stigmatisation.

It also announced that Clade II had two sub-clades, IIa and IIb, with viruses within the latter identified as being 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 an offshoot of IIa.

Clade IIb contains viruses collected in the 1970s, and from 2017 onwards.

"Looking through the genome, indeed there are a few genetic differences between the viruses from the current outbreak and the older Clade IIb viruses," the WHO told Agence France-Presse.

"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 still too early on in both the outbreak and laboratory studies to tell if the rise in infections could be driven by the observed genotypic changes in the virus, or are due to host (human) factors."

There is also no information yet on what the mutations mean in terms of how the virus interacts with the human immune response.

A surge in monkeypox infections has been reported since early May outside the endemic African countries.

The WHO declared the situation an international public health emergency on July 23. More than 35,000 cases in 92 countries, and 12 deaths, have now been reported to the WHO.

A first case of human-to-dog transmission of monkeypox - between two men and their Italian greyhound living together in Paris - was reported last week in the medical journal The Lancet.

"This is the first case reported of human-to-animal transmission... and we believe it is the first instance of a canine being infected," Dr Rosamund Lewis, the WHO's technical lead for monkeypox, told reporters.

Experts had been aware of the theoretical risk that such a jump could happen, she said, adding that public health agencies had already been advising those suffering from the disease to "isolate from their pets".

She also said "waste management is critical" to lowering the risk of contaminating rodents and other animals outside the household.

AGENCE FRANCE-PRESSE