Just under 1.2 million people in the United States acquired HIV as of 2019, according to the Centers for Disease Control and Prevention (CDC). About 13 percent of them didn’t know.

HIV is more common than average in men who have sex with men (MSM). In 2019, 65 percent of new HIV diagnoses were in gay men, bisexual men, or other MSM, per the CDC.

Here’s a look at why MSM have a higher risk of contracting HIV, as well as steps to prevent transmission.

Around the world, MSM are 25 times more likely than average to contract HIV, reports UNAIDS.

In the United States, gay men, bisexual men, and other MSM account for the majority of new HIV diagnoses.

Because HIV is more common among MSM, these men are more likely to have sex with someone who has the virus.

Several other factors also raise the chances of transmission across MSM.

HIV can be transmitted through contact with virus-containing:

  • blood
  • semen (including pre-seminal fluids, also known as “pre-ejaculate” or “pre-cum”)
  • vaginal fluids
  • breast milk

Some people contract the virus when they have sex without a condom or other barrier method. Still, this isn’t the only way to contract HIV.

The virus can be transmitted when someone with HIV shares needles, syringes, or other drug equipment with another person.

HIV can also be passed from a mother to child during pregnancy, childbirth, or breastfeeding.

Some people have contracted HIV after a blood transfusion or organ transplant that contained the virus. But because donor blood and organs have been routinely tested for HIV since 1985, the chance of this happening today is very low.

HIV disproportionately affects certain MSM populations.

Among MSM, Black and Hispanic men are at higher risk than white men of contracting the virus, reports the CDC.

This may be because, according to a 2017 report, Black and Hispanic gay and bisexual men are less likely to take preventive medication.

The reasons for this include the stigma surrounding same-sex experiences and the stress of enduring racism, discrimination, and racist systems that play a part in healthcare inequities.

Also, HIV also tends to affect people in under-resourced communities with less access to preventive HIV care.

Today, while many nations have more progressive policies, some areas across Africa, Russia, and the Middle East continue to enforce laws against same-sex activity. This cuts off access to preventive HIV care for these individuals.

Stigma plays a significant role in HIV transmission, despite advances in prevention and treatment.

Even in areas where same-sex activity is legal, the fear of stigma and discrimination that comes along with it can drive men to hide their sexual identity from healthcare professionals. This creates a barrier to testing and preventive treatment.

The stigma attached to HIV may also prevent people aware of their HIV-positive status from accessing and maintaining treatment to suppress their viral load and help stop the spread.

As a result, stigma further drives HIV transmission across the MSM community.

HIV can be transmitted through sex without a condom or other barrier method.

The chance of transmission is higher during anal sex without a condom or other barrier method than vaginal sex without a condom or other barrier method.

This is because the skin around the anus is thinner than the skin around the vagina, so small tears are more likely to occur during anal sex.

Someone without HIV is more likely to contract the virus during anal sex if they are the “receptive” partner (the partner whose anus is being penetrated by the penis).

Early diagnosis and treatment for HIV are important. Treatment with antiretroviral therapy prevents progression to AIDS. It can also reduce the virus to undetectable levels, at which point it can’t be transmitted to others.

The CDC recommends that MSM get tested for HIV at least once a year. People at higher risk of HIV may benefit from more frequent testing, such as every 3 to 6 months.

Not all MSM follow these recommendations. As a result, some may have HIV without realizing it. This can lead to delays in treatment and increase the chances of transmission.

As of 2018, approximately 1 in 6 MSM with HIV in the United States didn’t know they had the virus, reports the CDC. In that same year, per the CDC, only 65 out of 100 gay and bisexual men with HIV in the United States received some HIV care.

Some MSM don’t seek testing or treatment due to homophobic stigma or fear of discrimination.

Medications are available to reduce your likelihood of acquiring HIV.

These include pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP).

If someone without HIV is at a higher risk of contracting the virus, taking PrEP daily significantly lowers that risk.

If someone without HIV has a possible exposure to the virus, they can take PEP within 72 hours. This greatly reduces the risk of transmission.

Despite the availability of these medications, usage remains low among gay and bisexual men, particularly Black or Hispanic men, according to the CDC.

In 2017, the CDC reported, PrEP was taken by:

  • 19 percent of Black or African American MSM
  • 21 percent of Hispanic or Latino MSM
  • 31 percent of white MSM

Medical care can be limited for some people as not everyone has access. Even for those who do, not all medical professionals are comfortable prescribing these medications.

HIV is preventable. Here are a few ways to reduce the risk of transmission.

1. Use a barrier method during sex

Condoms and other barrier methods can protect against HIV and other sexually transmitted infections (STIs).

If you have HIV or another STI, getting treatment and using a condom or other barrier method every time you have sex can reduce the risk of transmission.

If you don’t have an STI, you can protect yourself from acquiring an STI by using a condom or other barrier method every time you have sex.

Also, it’s important to buy the right size condom for you and to use it properly.

2. Choose alternative sexual activities

Some activities carry a higher risk of HIV transmission than others.

The chance of transmission is high during anal sex without a condom or other barrier method.

The chance of transmission is low during oral sex or activities that don’t involve contact with bodily fluids.

3. Limit your number of sexual partners

The chance of HIV transmission increases with the number of sexual partners a person has.

4. Get testing and treatment

If you’re an MSM, consider getting tested at least once a year for HIV. People who have sex with multiple partners or partners of unknown HIV status should consider getting tested more frequently, such as every 3 to 6 months.

People who test positive for HIV should follow their doctor’s recommended treatment plan. Taking antiretroviral medication will lower the risk of complications and help prevent HIV transmission.

It also helps to ask your sexual partners about their testing history and status.

5. Take PrEP or PEP

If you don’t have HIV, ask a doctor whether you should take PrEP to lower your chance of contracting the virus.

If you have sex without a condom or other barrier method with someone who has HIV or someone who might have HIV, ask a doctor about PEP. You must take PEP within 72 hours of possible exposure and continue taking it for 28 days.

People who have HIV should encourage their partners to speak with a doctor about PrEP and PEP.

New HIV infections occur each year, with a large number affecting MSM.

Reduce your chances of contracting or transmitting the virus by using a condom or other barrier method during sex. Get regularly tested for HIV and talk with sexual partners about their HIV status.

Antiretroviral medications are available to treat HIV. They help prevent transmission and lower the risk of complications from HIV.

Medications are also available to reduce the chances that someone without HIV will contract the virus after exposure.