Of the cases interviewed, 99% of those infected are men and their average age is 38, the agency added after analysing 336 of the 366 confirmed cases found in the UK since the outbreak began last month.
The same overwhelming majority of cases – 99% – involve men who are gay, bisexual or have sex with other men, the UKHSA said. Interviews it has conducted with 45 men with monkeypox specifically about their sexual health found that 44% had visited “sex-on-premises venues” in the UK or abroad, such as saunas, sex clubs and dark rooms, while they were incubating the infection.
Tracing all the sexual partners of men who have contracted monkeypox will be hard, the UKHSA admitted, as “most cases reported having sexual contact with new or casual partners … where contact details were unavailable for tracing”.
The UKHSA report is based on close scrutiny of the history of the 336 laboratory-confirmed cases that had been identified in the UK by 8 June, including detailed questionnaires that 152 cases filled in. That total rose to 366 on Friday.