New Monkeypox symptoms are making cases harder to recognise

Some local health departments have already alerted health workers to the new symptom patterns. A July 18 advisory from New York City health officials describes “atypical features” in some cases, including a shortened incubation period of 2 to 5 days, lack of fever or swollen lymph nodes, and the presence of only a few, scattered lesions most prominent in the anus and genital area.

“These different presentations highlight that monkeypox infections could be missed or easily confused with common sexually transmitted infections such as syphilis or herpes,” said John Thornhill, a sexual health and HIV doctor and professor at Queen Mary University who also contributed to the study, said in a statement. “We therefore suggest broadening the current case definitions.”

The study looked at 528 cases across 16 countries, the largest case report to date. Almost all of them were men who have sex with men, or who identify as gay and bisexual men. One reassuring finding, Orkin said, is that though monkeypox has been known to cause more serious symptoms in immunocompromised people, including those with HIV, their study did not see evidence of increased disease severity among monkeypox patients with HIV.