Staphylococcus aureus is not classed as a sexually transmitted disease, even though it can show up on the genitals and pass between partners. It spreads through any close skin contact or shared items, and sex is just one of many ways that happens.1STDcheck.com. Is a Staph Infection an STD? Contagion Facts A staph boil in the groin doesn’t mean you caught an STD, but it is still worth telling a partner about.
Why Doctors Don’t Count Staph as an STD
Infectious-disease experts ask two things: is sex itself a route of spread, and does sexual behavior meaningfully change how common the infection is?2Clinical Infectious Diseases. Methicillin-Resistant Staphylococcus aureus Infections in Sex Partners: What Is a Sexually Transmitted Disease? For gonorrhea, HIV and hepatitis B, the answer is yes. For staph, including MRSA (staph that resists common antibiotics), the answer is no.3Clinical Infectious Diseases. Methicillin-Resistant Staphylococcus aureus Infections in Sex Partners: What Is a Sexually Transmitted Disease?
Picture a population where nobody had sex: chlamydia and gonorrhea would nearly vanish, but staph boils would keep appearing in families, teams and households. Plenty of non-STDs can be passed during sex, such as colds through kissing, and that doesn’t turn them into STDs.
Staph lives on people anyway. Many healthy people carry it on their skin or in their nose without being sick. In one group of adults, about half carried staph somewhere on the body, most often the nose and throat.4PubMed Central. High Perineal and Overall Frequency of Staphylococcus aureus in People Who Inject Drugs, Compared to Non-Injectors
In practice, that makes staph quite different from a true STD. Chlamydia is usually caught only through sex, while staph is caught from towels, gyms and family members. No routine STD panel tests for it. Being a carrier is normal and says nothing about risky behavior.
Because carrying staph is so common, a boil usually reflects staph that was already on your own body getting into a small break in the skin. A boil in the groin often can’t be traced to a particular person or a particular moment.
How Staph Can Pass Between Sexual Partners
Close skin-to-skin touch passes staph, and intimate activity involves plenty of it.5STDcheck.com. Is a Staph Infection an STD? Contagion Facts Staph can also live in the vagina, and partners can pass it back and forth mainly through skin and mucous-membrane contact.6PubMed. MRSA infection of buttocks, vulva, and genital tract in women In a few reported households, MRSA passed between heterosexual partners and caused new infections.7PubMed. Heterosexual transmission of community-associated methicillin-resistant Staphylococcus aureus
Staph can move from a carrier’s skin, nose or genital area to a partner’s skin by direct contact, then cause a boil if it enters a nick or a hair follicle. Hands matter too: staph in the nose or on a sore can reach the genital area on fingers.
Behavior matters more than identity. Sexual behavior is linked to carrying MRSA in both straight and gay people.8PubMed Central. Methicillin-resistant Staphylococcus aureus (MRSA) in men having sex with men (MSM): a systematic review Being a man who has sex with men isn’t the risk on its own; having multiple partners and using drugs during sex raise it.9PubMed Central. Methicillin-resistant Staphylococcus aureus (MRSA) in men having sex with men (MSM): a systematic review In some US cities, a drug-resistant MRSA strain spread among men who have sex with men, mostly as infections of the buttocks, genitals and the area between.10PubMed. Emergence of multidrug-resistant, community-associated, methicillin-resistant Staphylococcus aureus clone USA300 in men who have sex with men
Condoms protect only the skin they cover, so they don’t adequately protect against MRSA.11California Department of Public Health. Update on MRSA: Resistant Staph in Men Who Have Sex with Men Staph lives on the thighs, buttocks, groin and surrounding skin that touch during sex, and staph on hands or on a sore outside the covered area can still reach a partner. Condoms still protect against true STDs, so keep using them for that. For staph, covering a sore and avoiding contact until it heals does more than a condom. Avoid sex while a boil is open, draining or bandaged, and resume once the skin has fully healed.
When you tell a partner, name it plainly: a staph skin infection, a common germ on skin, not a sexually transmitted disease. Explain that it spreads by touch and shared towels, so they understand why you’re pausing sex and sharing nothing. Suggest they watch over the coming weeks for painful red bumps, especially around hair-bearing skin, and see someone if any appear. If either of you keeps getting boils, see a doctor together so the plan covers both of you.
Why Staph Infections Show Up in the Groin and Genitals
Some MRSA strains, especially a common community strain called USA300, readily settle on groin skin and around the anus.12PubMed Central. Evolution of community- and healthcare-associated methicillin-resistant Staphylococcus aureus In a sexual health clinic, most people carrying USA300 had it at a pelvic site, compared with fewer than 4 in 10 carrying other staph.13PubMed Central. High prevalence of colonization with Staphylococcus aureus clone USA300 at multiple body sites among sexually transmitted disease clinic patients: an unrecognized reservoir About 9 in 100 healthy women carry staph in the vagina, often along with the nose.14Annals of Internal Medicine. Vaginal Colonization with Staphylococcus aureus in Healthy Women: A Review of Four Studies Carrying staph around the genitals was more common among people who inject drugs, about 37% versus 17%.15PubMed Central. High Perineal and Overall Frequency of Staphylococcus aureus in People Who Inject Drugs, Compared to Non-Injectors Carrying staph in the vagina or around the anus can be a quiet source of repeated boils in the same region.
What it looks like there varies. In one group with a community MRSA strain, half the skin infections were in the area between the genitals and anus.16PubMed. Clinical manifestations and outcome of skin infections caused by the community-acquired methicillin-resistant Staphylococcus aureus clone ST80-IV MRSA can also cause small pus bumps in unusual places like around the belly button, chest, flanks and scrotum.17Cutis. Community-Acquired Methicillin-Resistant Staphylococcus Aureus Skin Infection Presenting as a Periumbilical Folliculitis
Hairy, warm areas get infected easily. Staph often infects hair follicles, and the groin and buttocks have many of them. Friction, sweat and tiny shaving nicks give it an easy way past the skin’s surface. Shaving the pubic area can carry bacteria along the shaved skin and produce a line or patch of bumps. Tight clothing and sweaty gym wear hold moisture against the skin and rub it, which adds to the risk.
Staph Bumps, Boils, or Herpes
- Folliculitis: a small pus bump centered on a hair with a red ring, common on thighs, buttocks and genitals.18PubMed Central. Skin Infections Caused by Staphylococcus aureus
- Boil: a deep, painful red lump around a hair that fills with pus over a few days.19PubMed Central. Skin Infections Caused by Staphylococcus aureus
- Abscess: a tender, very painful red swelling that turns soft as pus collects; fever is uncommon.20PubMed Central. Skin Infections Caused by Staphylococcus aureus
Staph infections can mimic a herpes outbreak.21Patient Care. Herpes Simplex and Staphylococcal Folliculitis A doctor may take a swab for a lab culture while starting treatment.22Patient Care. Herpes Simplex and Staphylococcal Folliculitis Misdiagnosis can delay the right treatment.23FastMed. Is it a Staph Infection or Herpes? What’s the Difference?
Some clues lean one way. Herpes often begins with tingling, burning or itching, followed by clusters of small blisters that break open and crust over. Staph lumps are more often single, firm and tender, and they fill with thick pus, often centered on a hair. Herpes tends to come back in the same area. These are tendencies, not dependable tests, and the two can look alike, so a swab is the reliable way to tell.
At the appointment, a clinician looks at the sore and may swab fluid from it, ideally early, before the lesion crusts over or heals. The swab can be tested for herpes and cultured for staph, and sometimes both are checked.
A genital sore is also a reasonable time for a full STD screen, since having staph doesn’t rule out having an STD at the same time. Tell the clinic about any new partners.
Treatment and When to See a Doctor
The first treatment for boils and abscesses is having a clinician cut and drain them.24Journal for Nurse Practitioners. Community-Associated MRSA Infections in Women For a simple boil in a healthy adult, draining may be all that’s needed. Antibiotics are added when there is fever or the infection is spreading.25Journal for Nurse Practitioners. Community-Associated MRSA Infections in Women In one group with MRSA, every abscess needed surgical draining.26PubMed. Clinical manifestations and outcome of skin infections caused by the community-acquired methicillin-resistant Staphylococcus aureus clone ST80-IV
Draining is quick. A clinician numbs the area, makes a small cut, lets the pus out and may pack the cavity so it keeps draining. The pain eases quickly once the pressure is released, and the wound usually heals from the inside out. You may be asked to return in a day or two to check it or change the packing.
Don’t squeeze a boil yourself. Squeezing can push bacteria deeper into the skin and turn a small boil into a bigger one, and it spreads pus onto nearby skin and your hands, which can start new bumps or pass staph to others. Warm compresses a few times a day help a boil soften and come to a head, which may let it drain by itself. See a clinician if it is large, very painful, in a sensitive area or not draining.
Serious complications are rare. Staph can cause toxic shock syndrome from infections like vaginitis, wounds after childbirth, or pelvic infection.27Global Library of Women’s Medicine. Serious Pelvic Infections and Toxic Shock Syndromes It can occasionally infect the womb and tubes, though this is not well studied.28Journal of Clinical Gynecology and Obstetrics. Staphylococcus aureus as Pelvic Inflammatory Disease and Tubo-Ovarian Abscess Pathogen
Get urgent care for fever, chills or feeling very unwell, or red streaks spreading from the sore. A sudden high fever with rash, vomiting or dizziness may signal toxic shock. In women, pelvic pain with fever also needs prompt attention.
Stopping Staph From Spreading at Home
In homes, staph spread most when people shared a bedroom or a bath towel.29CIDRAP. Study reveals how Staph, MRSA spread in households Sharing beds, hand towels, razors and toothbrushes also raised the chance of passing MRSA.30WashU Medicine. Drug-resistant staph can spread easily in household environments Use your own towel and razor and, while infected, your own bedding.
While a sore heals, keep it covered with a clean, dry bandage and change it whenever it gets wet or soiled. Wash your hands with soap after touching the sore or the bandage. Wash towels and sheets in hot water and dry them fully, since heat helps kill staph. Skip shared gym equipment and hot tubs until the skin has healed.
Recurring boils on the genitals or buttocks, or a partner with them, can mean staph is living in the vagina or another hidden site.31PubMed. MRSA infection of buttocks, vulva, and genital tract in women Swabs from one body site often miss staph; a nose swab finds only about half of carriers, a vaginal swab under 1 in 10.32PubMed. Screening for Staphylococcus aureus carriage in pregnancy: usefulness of novel sampling and culture strategies If infections keep returning, ask a doctor to swab several sites.
Tell the doctor about the pattern and any partner or household member with similar boils, so everyone’s situation is considered together. A doctor may then decide whether to treat to clear the carriage, and may include a partner at the same time so you don’t pass it back and forth.