The clap, the common nickname for gonorrhea, spreads primarily through sexual contact with an infected person. The bacteria responsible, called gonococci, pass between people via genital, anal, and oral sex, and emerging evidence suggests even deep kissing may play a role. Transmission is surprisingly efficient: a single act of unprotected vaginal sex carries roughly a 22% chance of passing the infection from a woman to a man, and about 75% from a man to a woman.
Vaginal and Penile Transmission
During vaginal intercourse, the bacteria travel in genital secretions and attach directly to the lining of the urethra in men or the cervix in women. Once attached, the bacteria are quickly pulled inside cells, where they multiply and eventually release new bacteria ready to infect the next partner. Sperm cells can also carry the bacteria on their surface, which may further aid transmission during unprotected sex.
The large difference in per-act transmission risk (roughly 75% male-to-female versus 22% female-to-male) exists because the cervix provides a larger, more receptive surface area for the bacteria to colonize, and because ejaculate delivers a concentrated dose of bacteria directly to that tissue.
Anal and Oral Routes
Rectal gonorrhea is common, particularly among men who have sex with men. In one Seattle clinic study, about 10% of men who have sex with men tested positive for rectal gonorrhea, compared to roughly 6% for throat infections and 5.5% for urethral infections. Notably, most rectal and throat infections (58%) occurred without any urethral infection at all, meaning the penis doesn’t have to be involved for the bacteria to spread.
Oral sex can transmit gonorrhea in both directions. Performing oral sex on an infected partner can lead to a throat infection, and having a throat infection can pass the bacteria to a partner’s genitals or rectum during oral contact. Throat infections are especially problematic because they’re harder to treat and can silently spread the bacteria to new partners. Oral-anal contact (rimming) has also been linked to both rectal and throat infections.
Kissing as a Possible Route
The bacteria have been detected in the saliva of people with throat infections, and a systematic review of five studies found a consistent link between tongue kissing and throat gonorrhea. Two of those studies identified kissing as an independent risk factor even after accounting for oral sex and other sexual practices. This is a relatively new area of research, and major treatment guidelines haven’t yet formally recognized kissing as a transmission route, but the evidence is building.
Nearly Half of Cases Have No Symptoms
One of the biggest reasons gonorrhea spreads so effectively is that many infected people don’t know they have it. A clinical audit of 142 confirmed cases in women found that 48% reported no genital symptoms at all on the day of testing. Only 11% had the kind of discharge typically associated with gonorrhea (yellow, green, or pus-like). Without routine screening, nearly half of these infections would have gone undetected.
Men are somewhat more likely to develop noticeable symptoms, but even among men, symptoms can take anywhere from 2 to 30 days to appear, with 2 to 5 days being most common. A person is contagious from the moment of infection, not from the moment symptoms show up. This gap between infection and symptoms (or the complete absence of symptoms) is what drives ongoing transmission in the community.
Transmission During Childbirth
A pregnant person with an untreated gonorrhea infection can pass the bacteria to their baby during vaginal delivery. The newborn’s eyes are especially vulnerable. Gonococcal eye infection in newborns typically appears 2 to 5 days after birth and, without treatment, can perforate the eye and cause blindness. In rare cases, the infection can also cause joint infections, meningitis, or blood infections in the newborn. Less severe forms include infections of the nose, vagina, or urethra.
Can You Catch It From a Toilet Seat?
This is one of the most persistent myths about gonorrhea. The bacteria are fragile outside the human body, but they’re not quite as fragile as often claimed. Lab studies have shown that gonococci can survive for up to 24 hours in genital secretions on surfaces like glass or towels at room temperature, and even longer in cold conditions. That said, survival on a surface is very different from actual transmission. The bacteria need direct contact with a mucous membrane (the lining of the genitals, rectum, throat, or eyes) to establish an infection. Casual contact with toilet seats, doorknobs, or shared clothing poses virtually no real-world risk.
How Long You’re Contagious After Treatment
Once you start antibiotic treatment, the infection doesn’t clear instantly. The CDC recommends avoiding all sexual activity for 7 days after treatment and waiting until any sex partners have also been treated and completed their own 7-day window. If symptoms were present, those should also be fully resolved before resuming sexual contact. Skipping this waiting period is one of the ways reinfection and continued spread happen, even among people who’ve been properly treated.