A Closer Look at the Monkeypox Outbreak’s Less Than Typical Symptoms

Considering monkeypox in the differential diagnosis is important for early detection and curbing transmission, according to researchers of an observational analysis from England.

Among 54 men who have sex with men (MSM) who were diagnosed with monkeypox, all presented with skin lesions, 94% of which were anogenital, while 67% reported fatigue or lethargy and 57% reported fever, noted Nicolò Girometti, MD, of the Chelsea and Westminster Hospital NHS Foundation Trust in London, and colleagues.

Due to the fact that one in four men had a concurrent sexually transmitted infection (STI) combined with the high observed rate of anogential lesions, it is likely monkeypox was transmitted during instances of “close skin-to-skin or mucosal contact, during sexual activity,” they wrote in Lancet Infectious Diseases.

Of note, 10 of the 54 men showed no prodromal symptoms. Five patients required hospital admission, mainly due to pain or localized bacterial cellulitis necessitating antibiotic intervention or analgesia, and were later discharged.

“Given the suggested route of infection via contact during sexual activity and the number of clinical findings differing from previous descriptions, we suggest that case definitions currently detailing symptoms such as acute illness with fever should be reviewed to best adapt to the current findings, as at least one in six of this cohort would have not met the current ‘probable case’ definition,” said Girometti in a press release.

The researchers also noted that it is important to consider these data cautiously to protect both patients and public health perceptions.

“Although all cases reported in this study were in MSM, it is essential to balance targeted health promotion to groups that are disproportionately affected by the current outbreak with the avoidance of intensive media coverage generating stigmatization, and to remain alert to the possibility of spread to other groups,” they wrote.

Sexual health clinics and services are encouraged to be aware of monkeypox symptoms that might be seen in their practices.

“It is possible that at various stages of the infection, monkeypox may mimic common STIs, such as herpes and syphilis, in its presentation. It’s important that sexual health clinicians and patients are aware of the symptoms of monkeypox, as misdiagnosis of the infection may prevent the opportunity for appropriate intervention and prevention of onward transmission,” said co-author Ruth Byrne, MBBS, also of the Chelsea & Westminster Hospital NHS Foundation Trust, in a press release. “Additional resources are urgently required to support services in managing this condition.”

For this analysis, Girometti and team included 54 MSM who had sought treatment at one of four London sexual health clinics from May 14 to May 25. Median age was 41, 70% were white, and 24% were living with HIV.

In addition to the majority reporting anogential lesions, 7% reported oropharyngeal lesions, and 89% reported lesions on more than one site. Lesions present in more than three sites, some outside the anogenital area, were found in 54% of the men with HIV.

Six men were noted to have clinical presentation that was “compatible with cellulitis.” Among the men who underwent sexual health screenings, 25% tested positive for chlamydia or gonorrhea, and one patient tested positive for herpes simplex.

While some of the men had traveled to various countries throughout Europe, only two had knowledge of coming in contact with an individual who was infected with monkeypox.

“Further studies are needed to confirm the modality of viral transmission occurring during this outbreak to inform infection control policies, contact tracing, and future options to tackle the spread of monkeypox virus in at-risk groups, with tools such as targeted education, health promotion, preventative or post-exposure vaccination, and antiviral therapy,” Girometti and colleagues noted.