A new study published in The Lancet Infectious Diseases found that the clinical profile in recent monkeypox cases is different than in past events, with fatigue and fever less common and genital skin lesions more likely.
This is the first study to look at these differences among cases in the current outbreak, and points to the important role sexual transmission among mostly men who have sex with men (MSM) has played in spreading monkeypox in non-endemic countries, many of which had never seen a monkeypox case before.
Most had 5 or more new partners
In the study of UK cases, all 54 of the participants identified as MSM, and their median age was 41. The patients presented to UK sexual health clinics during a 2-week period in May, at the beginning of the global outbreak.
None of the men had traveled to sub-Saharan Africa, but many reported recent European travel. Of the 54 men, 52 said they were not aware of being in recent contact with anyone with monkeypox.
Forty-seven of 52 men who answered questions on recent sexual history said they had at least one new sexual partner in the 3 weeks prior to symptoms, and 29 of 52 (55.8%) had more than 5 new partners in the 12 weeks prior to diagnosis.
Almost all (49/52) patients presented with lesions and rashes on their genitals or anal regions. Only five patients required hospitalization, and no one died. One-quarter of the patients also were diagnosed with another sexually transmitted infection at the same time as monkeypox.
"The commonly observed symptom of skin lesions in the anal and penile areas, and the fact that a quarter of the patients tested positive for gonorrhoea or chlamydia at the same time as the monkeypox infection, suggests that transmission of the monkeypox virus in this cohort is occurring from close skin-to-skin, for example in the context of sexual activity," said Ruth Byrne, MD, from the Chelsea & Westminster Hospital NHS Foundation Trust, in a press release on the study.
Study authors also suggested that the primary symptom of genital rashes should be added to case definitions of monkeypox to more accurately identify symptomatic individuals.
There are now more than 5,700 cases of monkeypox in non-endemic countries, mostly in Europe and North America.
Iowa, Wisconsin, Connecticut report first cases
US cases of monkeypox are continuing to grow, with Iowa, Wisconsin, and Connecticut reporting their first cases of the virus. According to the Centers for Disease Control and Prevention, the country has 460 cases in 32 states.
In Iowa, health officials said the patient likely acquired the virus when traveling internationally. In Connecticut, health officials confirmed the patient was a man in his 40s from New Haven.
California has the most the most cases in the country, with 95, followed by 90 cases in New York. Illinois has 53 cases.