London, June 14 : Tracing contacts of people infected with monkeypox virus is giving public health officials in the UK a hard time, with many having had unknown sexual partners in "cruising grounds, sex clubs and during chemsex sessions", according to a report. The first technical briefing for the disease by the UK Health and Security Agency (UKHSA) includes details of 45 confirmed cases, who were asked about their sexual health. The report "highlighted challenges" in controlling the outbreak, Telegraph reported. Nearly all (98 per cent) of the cases reported having sex with other men during the incubation period, with about half (44 per cent) reporting more than 10 sexual partners in the previous three months and group sex. About 20 out of 45 also reported attending "sex-on-premises", such as in saunas, dark rooms or sex clubs in the UK or abroad during the incubation period, while nearly 64 per cent met new partners via dating apps, the report said. "Traditional contact tracing as a primary control intervention in this specific group will be challenging as most cases reported having sexual contact with new or casual partners, sometimes in the context of cruising grounds or during chemsex, frequently where contact details were unavailable for tracing," said the report. As of June 12, the UKHSA has detected 104 additional cases of monkeypox in England, bringing the total number confirmed in the UK to 470 with 452 cases in England, 12 in Scotland, two in Northern Ireland, and four in Wales. The outbreak in the UK is currently classified as Level 2, meaning that transmission is confined to a subpopulation with close contacts, but the report said health officials were closely monitoring the situation for evidence of Level 3 - the stage before full community transmission, the report said. "We are working, both in the UK and together with global partners, to progress the investigations that we need to help us better understand the virus, its transmission and the best use of mitigations such as vaccines and treatments," said Dr Meera Chand, Director of Clinical and Emerging Infections, UKHSA, in a statement. "We use the new data rapidly to inform the public health response and we continue to work to reduce transmission. "We are grateful to all those who have come forward for testing and the patients who continue to help us understand the outbreak through participating in studies and investigations," she added. /IANS