Large study highlights new symptoms

Single ulcers, anal sores and mouth sores are all unique symptoms of the current monkeypox outbreak, according to the largest international series of monkeypox cases to date. These findings underscore the need to expand case definitions for the disease, say the researchers.

“While we expected various skin problems and rashes, we also found that one in ten people had only one skin lesion in the genital area and 15% suffered from anal and/or rectal pain” , said John Thornhill, MD, PhD, lead author of the research, said in a press release. Thornhill is a Medical Consultant in Sexual Health and HIV and Clinical Lecturer at Barts NHS Health Trust and Queen Mary University of London. “These different presentations highlight that monkeypox infections could be missed or easily confused with common sexually transmitted infections such as syphilis or herpes,” he said.

Since April 2022, more than 15,000 cases of monkeypox have been reported in 66 countries where the virus was not previously known to be present. The virus, a less serious cousin of smallpox, is endemic in parts of central and western Africa. In the current outbreak, infections have been overwhelmingly found in men who have sex with men.

In a study published July 21 in The New England Journal of Medicine, researchers reported clinical details and outcomes of 528 monkeypox infections in 16 countries. All cases were diagnosed between April 27 and June 24, 2022. Ninety-five percent of cases were suspected to have been transmitted through sexual activity, 98% of patients identified as gay or bisexual men and 75% of patients were white. . The median age of patients in this case series was 38 years and 90% of infections occurred in Europe. Forty-one percent of the patients were HIV-positive and 96% of them were receiving antiretroviral treatment. Of patients with HIV-negative or unknown status, 57% reported using HIV pre-exposure prophylaxis. About 3 in 10 people (29%) tested positive for concurrent sexually transmitted infections.

Nearly 3 out of 4 patients (73%) had anogenital lesions and 41% mucosal lesions. Fifty-four patients had a genital lesion and 64% had less than 10 lesions in total. Fever (62%), swollen lymph nodes (56%), lethargy (41%) and myalgia (31%) were commonly reported symptoms before the rash developed. Seventy patients (13%) required hospitalization, most often for severe anorectal pain and superinfection of the soft tissues. Only 5% of patients received specific treatment with monkeypox: intravenous or topical cidofovir (2%), tecovirimat (2%) and vaccinal immunoglobulin (


Dr Jeffrey Klausner

The study “significantly reinforces our current understanding that the overwhelming majority of cases have been sexually associated, primarily among men who have sex with men,” said infectious disease specialist Jeffrey Klausner, MD, PhD. at the University’s Keck School of Medicine. of Southern California, Los Angeles, in an interview with Medscape Medical News. He did not participate in the research. “Anyone can get monkeypox, but it spreads most efficiently through what we call dense networks – where there is close and frequent personal contact,” he said. “It just so happens that gay men and other men who have sex with men have some of these networks.”

The fact that most of the lesions are present in the genital and anal area – which is unique to this outbreak – indicates transmission of the infection through intimate contact, he noted. Yet, there is not enough evidence to suggest that monkeypox is sexually transmitted. Although most of the semen samples in the study tested positive for monkeypox viral DNA, it’s unclear if there’s enough virus present to cause transmission, Thornhill said. He noted that more research is needed.

Klausner also stressed the importance of developing new tests to diagnose monkeypox earlier to prevent the spread. The lab test for monkeypox requires a swab from a lesion, but this study showed most patients had noticeable symptoms before developing the standard rash or lesions, he said. Reliable tests using saliva or throat swabs could help detect infections more quickly, he noted. Patients are thought to be most contagious when they develop lesions, Klausner said, so diagnosing patients before that stage would allow them to be isolated earlier.

California-based lab company Flow Health announced a saliva-based PCR test for monkeypox on July 9, though the U.S. Food and Drug Administration (FDA) warned that test results from other types of specimens in addition to lesion swabs may be inaccurate. “The FDA is not aware of any clinical data supporting the use of other specimen types, such as blood or saliva, for testing for monkeypox virus,” the agency said in a July 15 statement. . “Testing samples not taken from a lesion can lead to false test results.”

Klausner does not report any relevant financial relationships.

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