What made the 2008 event so unusual was that many of the reported infections were passed during sexual activity. In the San Francisco area alone, 588 MRSA infections were confirmed in one area of the city, the Castro District, of which 25% were highly resistant to antibiotic treatment.
The infections were characterized by the formation of abscesses and ulcers on the buttocks, anus, and genitals, suggesting that sex was a new and unexpected mode of MRSA transmission.
MRSA vs. STIs
Despite the fact that the 2008 outbreak was furthered along by sexual contact, MRSA is not considered a sexually transmitted infection (STI). By definition, STIs are diseases in which sexual contact is a predominant mode of transmission. These include such common and uncommon STIs as:
ChlamydiaCrabsGonorrheaHepatitis B virus (HBV)Herpes simplex virus (HSV)HIVHuman papillomavirus (HPV)Mycoplasma genitaliumSyphilisTrichomoniasisUreaplasma urealyticum
By contrast, MRSA is passed by skin-to-skin contact and is not limited to sexual activity or intimate contact. As such, it is viewed more along the lines of hepatitis A, which can be transmitted during oral-anal sex, or scabies, which can result from sexual or nonsexual contact.
Factors for Transmission
Most MRSA infections are acquired while in hospitals (known as healthcare-associated MRSA). This is not only due to improper handwashing or the contamination of wounds and medical devices but also because hospital patients tend to be immune suppressed and less able to fight infection.
HIV Infection
When MRSA occurs outside of a hospital (known as community-acquired MRSA), even casual contact can transmit the infection. By and large, people who are immune-suppressed—such as the elderly or people living with HIV (human immunodeficiency virus)—are more likely to become infected than those with healthy immune systems.
To this end, HIV is believed to have played a large part in the 2008 outbreak given that men who have sex with men (MSM) account for over 80% of new infections in the United States each year.
Immunosuppression coupled with sexual activity and multiple sexual partners created something of a perfect storm for MRSA infection in communities hard hit by HIV. With that said, it doesn’t entirely explain how the outbreak started in the first place.
Crystal Meth Use
Researchers believe that the rise in the use of injected crystal methamphetamine among MSM is to blame. According to a 2012 study in the AIDS and Behavior journal, which evaluated the crystal meth epidemic in San Francisco in 2008, no less than 35% of MSM reported crystal meth use in the previous 12 months.
While it unknown how many of these men inhaled or injected the drug, the practice of shooting, or injecting, meth has gained in popularity. Not only is sharing needles a major risk factor for HIV and hepatitis C, but it can cause MRSA infection by introducing MRSA bacteria under the skin.
Once MRSA infection is established, it can be readily passed to others. A 2017 study in LGBT Health found that MSM with MRSA often had no initial symptoms but nevertheless had active bacterial reservoirs in the rectum, nasal passages, and other mucosal tissues.
MRSA is easier to transmit through sexual activity if there are multiple sex partners, broken or inflamed skin, shared toys, or unprotected sex. Under these circumstances, a few isolated cases can suddenly turn into a community crisis.
Prevention
Despite the risk of sexual exposure, MRSA is a rare occurrence even in groups considered to be at higher risk. While every effort should be taken to avoid spreading diseases through sexual networks, the larger concerns are the everyday routes through which MRSA can be spread.
As a rule of thumb, personal hygiene should prevail when it comes to preventing MRSA and other community-transmitted bacteria. Among the precautions:
Wash your hands frequently with soap and water, especially after going to the bathroom. This will prevent you from moving bacteria from one part of the skin to another. Wash with soap and water after sex as well as any other activity in which there was skin-to-skin contact (including sports or dancing). Do not share personal care items such as razors or tweezers. Keep cuts, scrapes, and scratches clean, dry, and covered. When at the gym, clean equipment with an antiseptic spray and use a towel whenever seated on a bench or floor mat.
If you have HIV, you should immediately start and adhere to antiretroviral therapy (ART, a combination of HIV medicines). Doing so not only suppresses the virus but allows your body to rebuild its immune defenses.
