British monkeypox patients are showing symptoms different from previous outbreaks, the first study to examine British cases said on Friday, prompting researchers to update the definition of the disease.
Until a few months ago, monkeypox was largely confined to western and central Africa, where new outbreaks were usually caused by humans being infected with the virus from animals such as rodents.
But as of May, more than 3,400 cases have been registered worldwide, the vast majority in Western Europe among men who have sex with men and are known to be unrelated to cases south of the Sahara.
Britain discovered some of the earliest new global cases and the first study of patients there was published Friday in the journal The Lancet Infectious Diseases.
The researchers analyzed 54 monkeypox patients in London, all men who have sex with men, who accounted for 60 per cent of UK cases as of 26 May.
All but two of them were unaware that they had been in contact with someone who had monkey pox.
A quarter of the men were HIV positive and a quarter had a sexually transmitted disease while they had monkey pox.
All patients had skin lesions, 94 percent of which were in the genital and anal areas.
These factors suggest that the virus is transmitted during skin-to-skin contact such as during sex, the study said.
The World Health Organization is investigating cases of semen testing positive for monkey pox but insists the virus is not sexually transmitted and is mainly spread through close contact.
– Less fever, fatigue –
Only 57 percent of cases in the UK had a fever, compared to 85-100 percent of outbreak cases before this year.
Previous outbreaks also saw many more lesions on limbs, faces and necks.
However, in three-quarters of British cases, lesions were in only one or two areas, usually on or around the genitals, the study said.
The UK patients also tended to have mild cases lasting less than three days, of which only five were hospitalized.
The study’s lead author, Nicolo Girometti, said the UK definition of monkeypox symptoms, which describes it as an acute febrile illness, “needs to be revised to best adapt to current findings”.
“At least one in six of this cohort would not have met the current definition of ‘probable case’,” said Girometti of the Chelsea and Westminster Hospital NHS Foundation Trust.
Paul Hunter, an infectious disease expert at the British University of East Anglia who was not involved in the study, said he didn’t think the UK needed to change its definition of monkeypox as it is currently “very broad”.
Hugh Adler of the Liverpool School of Tropical Medicine told AFP that the monkeypox spreading worldwide is unlikely to represent a new form of the virus, as other studies have shown “there have been no massive genetic changes”.
Lesions on genitals suggest the virus spreads in the UK through contact during sex, while previous African cases may have had lesions on their hands from touching an infected animal or patient, he said.
He added that the study showed that monkeypox may initially resemble sexually transmitted diseases.
“Any new rashes in a man who has sex with men should be considered in the current climate for monkey pox testing, even if they have no other symptoms,” he added.
(This story was not edited by NDTV staff and was generated automatically from a syndicated feed.)