Should Mpox Be Called an STI?

The increasing number of cases of mpox (formerly known as monkeypox) in the U.S. is raising concern—especially among the LGBTQ+ community. In August, mpox was declared a national public health emergency.

Currently, thousands of cases in the U.S. are largely documented in men who have sex with men (MSM), and is being spread through sexual contact. This is prompting debate over whether the disease should be referred to as a sexually transmitted infection, or STI.

Many experts and health groups, including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), argue that because mpox is passed on through close physical contact of various forms—which can be non-sexual or sexual in nature—it should not be called an STI. What’s more, there’s also concern that calling mpox an STI creates greater stigma around the disease and the community it is currently affecting.

While mpox is not an STI in the traditional definition, Robert L. Murphy, MD, a professor of medicine at Northwestern University who specializes in infectious diseases, says the virus that causes mpox is being spread sexually the majority of the time right now in the United States.

But the possibility of sexual transmission does not mean an infection qualifies as an STI. Plus, the disease can be spread through other forms of direct contact, whether skin-to-skin or via bedsheets used by someone with mpox.

Whether we call it an STI or not, making it clear that mpox is largely circulating through sexual contact and among men who have sex with men is important for prevention and treatment efforts, as well as understanding risk.

The WHO says raising awareness of risk factors and educating people about the measures they can take to reduce exposure is the main prevention strategy.

“It’s not a classic sexual transmitted infection, but it’s being sexually transmitted…I think we have to just deal with the facts at hand,” Murphy tells Verywell. “You don’t have to have sex to spread it, but I think that [nuance] has to be part of the equation.”

What Is an STI?

STIs, sometimes called sexually transmitted diseases (STDs), are infections or diseases that primarily spread through sexual contact. They can be bacterial or viral, and include chlamydia, gonorrhea, herpes and HIV. STIs can spread through bodily fluid—like semen, blood or vaginal secretions—or via skin-to-skin contact.

Anu Hazra, MD, an assistant professor of medicine at the University of Chicago who specializes in infectious diseases, tells Verywell that while he has reservations about classifying mpox strictly as an STI, there is data supporting the fact that this current mpox outbreak is sexually transmitted.

“We’re seeing levels of monkeypox DNA in people’s semen, in their rectum. We’re seeing it in sexual sites,” Hazra says. “What I have come to say is that monkeypox can be spread in many different ways, and sexual transmission is one of them.”

This Mpox Outbreak Is Unique

Hazra says that mpox has been around for more than half a century and is endemic in parts of central and western Africa. The disease is caused by a zoonotic virus, which means it can spread from animals to humans. (Examples include getting scratched by an infected animal or eating meat of an infected animal.)

When it comes to human-to-human transmission, prior to this outbreak, the mpox virus typically spread through close contact with an infected person’s respiratory droplets or skin lesions. It can also be spread through shared, contaminated household items like bed sheets or towels.

While research on this outbreak is still emerging, recent data out of Spain suggests the majority of cases happen because of contact during sex, as opposed to any sort of airborne transmission.

Hazra says whether the transmission route of mpox now makes it an STI comes down to what we define as an STI. Do we only classify STIs as infections that can really only be spread through sex or intimate contact, and not any other way? Or do we consider them infections that can be spread through close contact—which is often required for sex?

“We don’t consider COVID an STI, even though if you have sex with someone who has COVID you will likely get infected with COVID,” Hazra says. “A lot of agencies in the United States have moved to the terminology ‘sexually associated infection,’ which gets largely pedantic at that point.”

Why the Messaging Matters

Because the public is aware that mpox is spreading among men who have sex with men, it’s important to state the facts on how it’s being transmitted, Hazra says. This can be done without stigmatizing sex, or the communities it is currently affecting.

This is where nuance is important. Hazra explains there can be implications when referring to mpox as an STI as it can affect whether or not someone feels comfortable reporting symptoms—especially if there’s a belief the virus is only passed on through sex.

What’s more, men who have sex with men have historically faced discrimination in healthcare, and members of the LGBTQ+ community often still face barriers today.

“This illness is being sexually transmitted among marginalized populations, and that can oftentimes impact how people may choose to not come forward with symptoms or with testing,” Hazra says. “Those are some of the implications in the back of my mind that hold me back from saying this is for sure an STI.”

Murphy explains that even though sexual contact is where we are seeing the majority of mpox spread right now, that doesn’t mean that people should assume they can’t get the disease any other way. People outside the MSM community can also contract mpox, so other groups need to stay vigilant, he says.

Hazra says it’s important that people who work in the sexual health community—especially LGBTQ+ health—lead the way on messaging around mpox, along with those in the public health community. It can be dangerous when outside voices try to control the narrative when it comes to historically marginalized groups and their well-being.

“It’s not the facts [around mpox] that are stigmatizing,” Hazra says, “It’s how we interpret the facts, or the framework we put on the facts that ends up causing stigma.”