Monkeypox Is a Sexually Transmitted Infection, and Knowing That Can Help Protect People

As data come in from around the world, a clear picture is emerging of who is being affected by the recent outbreak of monkeypox (MPX): Outside Africa, 99 percent of the cases have been in men, and 92 to 98  percent have been in self-identified men who have sex with men. Also, the cases in the Europe Union, the U.S. and the U.K. have been in men who are living with HIV.

In the U.S., MPX is overwhelmingly affecting Black and Latino men who have sex with men. If this dynamic is not corrected, this racial disparity will grow worse, as my research has shown has happened with HIV.

It’s happening again. In Chicago, where I got one MPX vaccine shot, almost everyone in line but me and a friend were white. Reports from friends and news organizations corroborate that some gay men  of means in the U.S. are even traveling to Canada to get vaccinated. 

The result? MPX is already receding among white men who have sex with men and pooling among Black and Latino men who do so. 

I have encountered a surprising amount of conflict—within institutions and even inside of some LGBTQ circles—about explicitly addressing these obvious paths of infection. Naming who is being affected and how transmission is happening is not homophobic or racist. Rather not naming, researching, preventing and addressing how transmission is happening will keep people from understanding how to prevent infection, allow unnecessary worry, and exacerbate racist and homophobic social determinants of health.

There is sufficient evidence to urgently study how this version of MPX may be transmitted through genital secretions or skin-to-skin friction, perhaps accounting for why there is a particular risk among receptive sex partners during anal intercourse.

A clearheaded review of the current literature, coupled with compassionate public health responses rooted in queer health and racial equity, can illuminate the best path for reporting on and protecting people during this health emergency.

When I started reading research on the MPX outbreak, I hypothesized that there must be a sexual component to how it was moving. I have never seen any virus so connected to one activity, not even HIV.

I began thinking about MPX as a sexually transmittied infection. This didn’t feel controversial to me, nor did I think any such categorization would mean MPX would only move sexually. For more than a decade, I have studied a variety of viruses categorized by the Centers for Disease Control and Prevention as sexually transmitted infections, or STIs, (including HIV, hepatitis and herpes) that have many modes of transmission.

But it’s important to understand how infections move sexually to research how they work and to prevent transmission whenever possible.

In the past few months, there has been considerable backlash to naming MPX an STI out of the usually well-intentioned but ultimately misguided belief that doing so will increase stigma. One objection, as medical anthropologist Harris Solomon has put it, has to do with how people in the U.S. treat sex as an identity and not as an action. Because we often conflate sex with who you are rather than seeing it as something you do, many people think diagnosing the risk of an action says something about people. But while sex is a necessary part of life, it is also an action like riding a bike or smoking, with its own risks and pleasures—and it must be studied rigorously while trying to protect public health.

The other dynamic is believing that gay sex is so bad and shameful, it must not be spoken about, let alone highlighted during a public health emergency. Intended as such or not, this is homophobic.

A study published in the BMJ in late July found 196 of 197 cases of MPX in London were in people who identified as men who had sex with men, creating an “unprecedented community transmission of monkeypox virus among gay, bisexual, and other men who have sex with men seen in the UK and many other non-endemic countries.” The very graphic photographs in the study illustrated how this variant of MPX—which differs from the endemic virus that jumped from animals to humans  in West and Central Africa—has shown a significant change.

Previously people infected with MPX would get lesions on their hands, face, back and feet, regardless of where on their body they had come into contact with the virus. But in the BMJ paper, lesions also appeared on the genital and in perianal area, showing that this form of the virus had different symptoms and suggesting it was perhaps transmitting differently, too. (The photographs show symptoms so severe that they put to rest any notions that large numbers of straight people are secretly suffering and not seeking medical attention out of embarrassment.)

The new outbreak is not entirely unprecedented. In 2017 a Nigerian doctor named Dimie Ogoina diagnosed someone with MPX who was, as he told NPR, the first case in his country in 38 years. (Later, he confirmed that the patient had been infected by another human rather than an animal.) Then Ogoina found an outbreak composed almost entirely of young men who weren’t handling animals. Many presented with genital lesions and ulcers. He published his findings in 2019, including his observation that “although the role of sexual transmission of human monkeypox is not established, sexual transmission is plausible in some of these patients through close skin to skin contact during sexual intercourse or by transmission via genital secretions.” But the global scientific community didn’t heed his warning. 

A study in the Lancet this month of 181 monkeypox cases in Madrid and Barcelona, Spain, bolsters the case of sexual transmission. Among the 92 percent of cases who identified as men who have sex with men, “participants reporting anal-receptive sex were more likely than others to have early systemic symptoms before developing skin lesions. One explanation is that anal sex might damage the epithelium [a very thin layer of tissue] and enable blood entry, allowing greater viraemia at an early stage when local lesions have not yet developed.” While the authors conclude, “There are questions about whether monkeypox is sexually transmitted via semen and vaginal secretions,” they note that “the extended definition of sexually transmitted infections such as syphilis and herpes simplex includes [when pathogens] are transmitted through superficial abrasions in the skin or mucous membranes.”

Skin-on-skin transmission during sex is a sexually transmitted infection. In the U.S., we have trouble talking about sex in general and gay sex in particular. The university where I work sent an e-mail and posted a message online to its entire community that said, “Monkeypox is not a sexually transmitted infection or disease, nor is it linked to sexual orientation”—phrasing in which sex was dealt with as an identity, not an action.

Meanwhile the virus in the U.S. is not just moving within the MSM community as a whole but particularly among Black and Latino MSM. In the first data broken down by race and ethnicity by the CDC, as reported by the Washington Post, among cases in which this information was known, 32 percent were Latino, and 26 percent were Black.  On August 10 the Atlanta Journal-Constitution reported that data from the Georgia Department of Public Health showed an astounding 82 percent of MPX cases were Black. The same day the North Carolina Department of Health and Human Services reported 122 cases in that state—“all in males and nearly all in men who have sex with men,” with “70% of cases … in Black/African American men and 19% in White men.”

North Carolina added data I’ve been waiting to see: “only 24% of vaccines have gone to Black/AA [African American] recipients, while 67% have gone to White recipients.”

Often some people naively hope a drug or a vaccine to treat an infectious disease will make racial disparities disappear. But this kind of inverse relationship between who is at risk and who gets vaccinated has been seen with COVID and HIV. If uncorrected, it means racial health disparities will get worse, pooling the virus even more in what I call a “viral underclass.”

In my own research, I found that when the CDC began looking at racial disparities in AIDS in the 1980s, Black men were about three times more likely to have an AIDS diagnosis than white men. By 1996, the year HIV medications became available, the ratio had doubled to about six to one. By 2015, it had increased to almost nine to one. This is because in 1996 white gay men started getting HIV drugs, which lowered viral loads dramatically in their social networks. Black people largely did not get the drugs—and so the virus moved more among Black people and concentrated in that population, and the disparity grew.

As a study in Belgium published in Nature Medicine last week illustrates, one way to more precisely understand how MPX is moving would be to test for it during routine STI screenings for men who have sex with men. The researchers “retrospectively screened 224 samples collected for gonorrhoea and chlamydia testing using a monkeypox virus (MPXV) PCR assay, and identified MPXV DNA-positive samples from four men,” even though, “at the time of sampling, one man had a painful rash, and three men had reported no symptoms.” Meanwhile a French study in the Annals of Internal Medicine performed anorectal swabs on 200 men undergoing STI testing and found 13 of them—6.5 percent—were asymptomatically positive for MPX.   

We also need to urgently study why even people with undetectable levels of HIV—who have a viral load so low that it is causing no harm to their immune systems and can’t be transmitted to others—are still so overrepresented among MPX cases. 

The irony of needless panic about MPX in public places is that people should be masking in subways for COVID. SARS-CoV-2, the virus that causes COVID, is airborne and has killed a million of Americans. MPX, which is not airborne in the same way, has almost exclusively transmitted itself sexually, and it has not yet killed any Americans.

While the  CDC does not include  MPX on its list of sexually transmitted viruses, it  has bizarrely started calling it sexually transmissible. Regardless, the research is clear: while 1 to 6 percent of cases of MPX in the U.S. may be transmitting in other ways, 94 percent of infections are moving sexually among self-identified men who have sex with men, especially among Black and Latino men. This is nothing to be ashamed of or to hide; it is something to be addressed to protect people who deserve the dignity of a proactive campaign that centers our needs during a public health emergency.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.