The symptoms of patients with monkeypox in the United Kingdom differ from those in previous outbreaks of the virus, a new study shows.
It said there have been fewer reports of fever and tiredness while reports of skin lesions in the genital and anal areas have been more common.
Location of the lesions suggests transmission during intimate contact, and researchers called for more resources to support sexual health clinics.
"Currently, the U.K. and several other countries are seeing a rapid increase in monkeypox cases among individuals attending sexual health clinics, with no apparent links to countries where the disease is endemic," said Dr. Nicolo Girometti of the Chelsea and Westminster Hospital NHS Foundation Trust in London. "Monkeypox is a novel diagnosis within the sexual health setting and our study, the first to publish on cases from this U.K. outbreak, will support future case finding and clinical care."
The study includes 54 cases collected from four London sexual health centers. Each had a laboratory-confirmed infection.
All but two of the patients said they were unaware of having been in contact with a known monkeypox case. None had traveled to sub-Saharan Africa, where the disease is common. Many had recently visited other European countries.
Each of the patients identified as men who have sex with men. About 90% reported at least one new sexual partner during the three prior weeks. Nearly all reported inconsistent condom use. More than half had more than five sexual partners in the previous 12 weeks.
About 94% of patients had at least one lesion on their genitals or around the anus. Most had mild illness, though five were hospitalized for pain or infected skin lesions. All were discharged later.
"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 gonorrhea 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 Dr. Ruth Byrne of the Chelsea and Westminster Hospital NHS Foundation Trust. "However, this finding may be biased by the fact that we are sexual health providers and hence may not reflect transmission in the wider population."
Monkeypox infection with these symptoms may mimic common sexually transmitted infections, such as herpes and syphilis, she said.
"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," Byrne said.
While fewer of these patients were weak, tired or had a fever than in past outbreaks, about 18% had no symptoms before skin lesions emerged.
The authors noted that their findings might not be representative of the outbreak because their testing was done in a specific group of infected individuals.
The findings were published July 1 in The Lancet Infectious Diseases.
The U.S. Centers for Disease Control and Prevention has more on monkeypox.
SOURCE: The Lancet Infectious Diseases, news release, July 1, 2022