Monkeypox patients in the UK have markedly different symptoms to those seen in previous outbreaks, according to researchers in London, raising concerns that cases are being missed. Patients reported less fever and fatigue and more skin lesions in the genital and anal areas than usual with monkeypox, according to the study of 54 patients at London sexual health clinics in May this year. Monkey pox, a usually relatively mild viral disease endemic to many countries in west and central Africa, has caused more than 5,000 cases and one death outside those areas – mainly in Europe – since early May. Cases have also increased in countries where it spreads most often, according to the World Health Organization. The research from London, published in the Lancet Infectious Diseases Journal, follows suggestions from public health agencies such as the US Centers for Disease Control and Prevention that the outbreak – which is spreading mainly among men who have sex with men – is uncommon. The authors, from a number of institutions including Chelsea & Westminster Hospital NHS Foundation Trust, said case definitions should be reviewed to avoid cases being overlooked, particularly as monkeypox can ‘mimic’ other common sexually transmitted infections (STDs) such as herpes and syphilis. The study also found that a quarter of the monkeypox patients were HIV positive and a quarter had another STD. “Misdiagnosis of infection can prevent the opportunity for appropriate intervention and prevention of further transmission,” said Dr Ruth Byrne, from the trust. Monkeypox is spread through close contact, and researchers are working to determine whether it can also be transmitted through semen, the classic definition of sexual transmission. [L1N2Y20QL] David Hayman, an infectious disease epidemiologist and WHO adviser on the outbreak, said it was important to control the spread without stigmatizing those affected. “This includes working with populations at greatest risk to try to help them understand how easy it is to prevent this infection – simply by avoiding physical contact in the genital area [when a rash is present]”, he told Reuters. Our Morning and Afternoon Newsletters are compiled by Globe editors, giving you a brief overview of the day’s most important headlines. Register today.