Monkeypox mainly spreads among women and nonbinary people through sexual contact, but some infections could be flying under the radar as they are often misdiagnosed as other diseases known to be sexually transmitted, according to a study published Thursday in the Lancet medical journal, important findings that provide much needed insight into how the disease affects nonbinary people and cisgender and transgender women.
The study, the first to focus on monkeypox transmission among cisgender and transgender women and nonbinary people assigned female at birth, found that sexual contact was likely responsible for 73% of monkeypox infections in this group.
There were key differences between cis women and nonbinary people and trans women, the researchers said, with almost all monkeypox infections among trans women thought to have been acquired through sexual contact.
In contrast, around 24% of cis women and nonbinary people were thought to have acquired monkeypox outside of sexual contact, the researchers said, including household exposure and occupational exposure in healthcare workers.
The figures—based on data from 136 women (69 cis, 62 trans) and five nonbinary people with confirmed cases between 11 May and 4 October across 15 countries—compare to rates of almost 100% transmission through sexual contact reported among men.
As with many cases during the global outbreak, researchers said symptoms tended to match likely routes of transmission—anal and genital lesions have been characteristic— and were frequently misdiagnosed as sexually transmitted infections, particularly among cis women.
Some 33% of cis women received a misdiagnosis before a monkeypox diagnosis was confirmed and nearly half experienced delays and needed more than one appointment to get a diagnosis.
Monkeypox has caused limited and sporadic outbreaks in parts of Africa for decades, though it was largely ignored by the rest of the world until it started spreading more widely this year. The global outbreak differed in scope, scale, geographic range, speed and demography of previous outbreaks, which were usually relatively confined, unsustainable and stemmed from the virus spilling over from unknown animal reservoirs (likely rodents). Data from the outbreak suggests the virus is almost exclusively spreading through sex among gay, bisexual and other men who have sex with men, and it was accompanied by a different set of symptoms than what was seen in previous outbreaks. Options for treating and vaccinating against monkeypox are limited—few exist and most were developed for use against smallpox, a related disease that has been eradicated—and supplies are critically short, as countries where monkeypox has historically spread have predictably been last in line while wealthy countries buy up stock. The outbreak appears to be slowing, possibly more due to behavioral changes in at-risk groups than vaccination efforts.
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Though women account for a very small fraction of monkeypox infections reported during the current global outbreak, the researchers in Thursday’s Lancet study said they “anticipate that this might change as the outbreak evolves.” The study’s findings, particularly the higher rates of misdiagnosis and multiple appointments before confirmation of diagnosis in cis women and nonbinary people compared with trans women, highlight the need to improve training about and awareness of monkeypox among health professionals beyond sexual health clinics.
The prospect of monkeypox spreading to and among children was a significant concern during the global outbreak, particularly as this group has a higher risk of severe disease. While many experts believed monkeypox posed little risk to children, fears that the virus would establish itself in populations like children loomed large. These fears have not come to pass and though a small number of children have contracted monkeypox, they make up a miniscule fraction of the total number of cases around the world. The researchers said their study also suggests a limited risk to children. Only two children living in the homes of the cis women involved in the study acquired monkeypox, though 26% had children living in their homes, the researchers said, suggesting “very limited chains of transmission” in line with previous research. Pregnant people also face higher risks of severe disease from monkeypox, though the researchers said their study could not shed light on the issue as it included just two pregnant people who had not yet delivered.
80,064. That’s how many cases of monkeypox have been recorded in more than 100 locations around the world this year so far, according to CDC data. Fewer than 1,000 of these infections have been recorded in locations that have historically reported monkeypox, though cases are likely to go undocumented in some of these areas. Some 51 deaths linked to monkeypox have been reported so far, 13 of which were in locations that historically reported outbreaks.
Before the global outbreak, monkeypox was not thought to be a disease that transmitted sexually. Transmission almost exclusively in networks of men who have sex with men highlighted the possibility, though there is a difference between something being passed on through the close contact that accompanies sex and something that can only be acquired in a sexual setting, for example through semen or vaginal fluid. Increasingly, evidence is emerging that monkeypox may possibly fit both categories. The virus has previously been found in the semen of men with monkeypox. The researchers of this study tested vaginal swabs for the virus as well, finding monkeypox DNA in all 14 swabs taken. This strengthens the idea that monkeypox can transmit through bodily fluids as well as close skin-to-skin contact.
Lead study author Chloe Orkin, a professor of HIV medicine at Queen Mary University of London, said case definitions “have rightly focused on the most affected groups, sexually active men who have sex with men,” during the global outbreak, adding that public health efforts have been tailored to reach this group. “However, as the outbreak progresses, it’s important to also focus attention on underrepresented groups such as women and nonbinary individuals to better understand their risk,” as well as to understand how the “infection manifests in women” so doctors can recognize it.
By Robert Hart, Forbes Staff