Going viral: Which STDs rule your city?

Few people enjoy talking about venereal diseases, but just because we don’t overshare about them doesn’t mean they don’t exist. Particularly if you live in, say, Memphis, Tennessee.

We looked at four STDs—chlamydia, gonorrhea, syphilis, and HIV—and mapped out rates across the country, according to data from the CDC’s most recent surveillance reports. Cities with denser populations tend to see higher rates, but rates vary significantly from region to region.

What about herpes, you ask? Or HPV? Or crabs? These don’t qualify as notifiable diseases, which means the CDC does not collect geographic data on them. (So if you’re trying to figure out the herpes capital of America and won’t take the world’s easiest ‘Yo Momma’ joke for an answer, I’m sorry, but you’re SOL.)

Check out these maps and see where your city ranks. Most importantly, educate yourself!

Chlamydia: “The Silent Epidemic”

Transmitted: Vaginally, orally, anally, or from mother to child during birth

Chlamydia is the most commonly reported STD in the country, caused by the rod or round-shaped bacteria Chlamydia trachomatis. In 2013, the CDC logged more than 1.4 million cases, hitting 15 to 24 year-old women the hardest. Indeed, women are infected at much higher rates than men and encouraged to get screened more frequently. Untreated infections in women can lead to pelvic inflammatory disease, causing serious damage to the reproductive system. Men, on the other hand, suffer little damage from the disease.

Symptoms: There’s a reason chlamydia is known as the “silent epidemic”—most people don’t show symptoms, and those who do may not experience them until long after a sexual encounter with an infected person (we’re talking anywhere between weeks and years). Symptoms can include abnormal discharge and/or a burning sensation while peeing.

Treatment: Chlamydia is a fairly manageable infection if diagnosed early, but don’t just Purell your junk and call it a day. Early-stage treatment consists of antibiotics.

Test: Pee in a cup (urine sample) or swab (urethra for men and cervix for women and/or rectum)

What’s up with Memphis?

As the map above reveals, Memphis is the Chlamydia capital of the country. Fifteen to 19 year-old girls experience the highest rates, and the disease hits the city’s black population hardest. According to Shelby County chief of epidemiology David Sweat, it’s difficult to pinpoint exactly why the rates are so high, but social factors play a role.

“About 30 percent of our kids live in poverty, which is an exceptionally high rate,” Sweat told Fusion, noting that many sexually transmitted infections are ones of poverty. “If you are in a place and you don’t see a lot of opportunity down the road, instant gratification is easier to pursue.”

Shelby County offers free STD testing at local schools, and its health department is in the process of revamping.

Gonorrhea: “The Clap”

Transmitted: Vaginally, orally, anally, or from mother to child during delivery

Gonorrhea is caused by the coffee-bean shaped bacteria Neisseria gonorrhoeae. In 2013, more than 333,000 cases were reported—and for the first time since 2000, the CDC logged more cases in men than women. Like chlamydia, if left untreated, the consequences can be serious. Along with long-term pain, for women, gonorrhea can lead to reproductive complications like ectopic pregnancy or blocked fallopian tubes. For men, it can lead to a painful inflammation of the testicles that can affect fertility. And not in a good way.

Why is it called “the clap”? There’s some debate over the name’s origin, but it likely derived from the French clapoir, which is an old-timey word for a sexual sore—and led to French brothels being dubbed clapiers, for their high infection rates.

Symptoms: For women, symptoms include a burning sensation while peeing, increased vaginal discharge, vaginal bleeding between periods, and sometimes painful intercourse. Men may also experience a burning sensation while peeing or abnormal discharge from the penis. Similar to chlamydia, not everyone with the infection displays symptoms.

Treatment: Antibiotics

Test: Pee in a cup (urine sample) or swab (urethra for men and cervix for women and/or rectum)

Don’t fear the toilet seat

Let it be known: You cannot get gonorrhea from toilet seats. Actually, you can’t catch much from toilet seats other than a horrifyingly damp upper thigh/lower butt area. We know this because we asked Jenelle Davis, who founded the The STD Project, an online resource that works to combat stigma. “Everyone still goes into the bathroom and hovers over the darn toilet seat,” she said. “Please stop hovering. It is scientifically improbable to get an STI from a toilet seat, mainly because of the physiology of the infection itself.”

Davis explained: “Most infections don’t last outside of the human body for any length of time. The ones that do need an entry point into the system. It’s not just touching it with your skin, which actually provides a barrier.”

So why does the toilet seat myth persist? Davis says it largely comes down to stigma: It’s easier for some people to say they contracted an infection from a toilet seat than to admit they contracted it through sex.

Syphilis: “The Great Imitator”

Transmitted: Vaginally, orally, anally

Syphilis is caused by a spirally bacterium called Treponema palladium. The rates for primary and secondary syphilis (details on these distinctions below) are much lower than those of chlamydia and gonorrhea: The CDC logged 17,375 cases of primary and secondary syphilis in 2013. While the rate for women remained unchanged from 2012 to 2013, the rate for men increased 12 percent, and there is a relatively high incidence of syphilis among men who have sex with men.

Symptoms: Syphilis is known as the “great imitator” because it presents with symptoms that are easily confused for other diseases. Technically, there are four stages of the disease: primary, secondary, latent, and late. Primary stage symptoms include “chancres” or sores in the mouth, vagina, or rectum. Secondary symptoms include sores along plus rough rashes (that won’t necessarily itch). The symptoms of primary and secondary syphilis may clear up without treatment, but that doesn’t mean you’re cured—in the latent stage, the symptoms disappear, but the infection is still present. Not everyone develops late-stage syphilis from the latent stage, but late-stage symptoms are very serious, including paralysis, numbness, blindness, and even death—and can surface 10 to 30 years after the infection begins.

Treatment: You guessed it: Antibiotics. Diagnosing and treating syphilis in the early stages is key.

Testing: Blood sample or fluid/tissue sample from an open sore

HIV (Human Immunodeficiency Virus)

Transmitted: Vaginally, anally, orally (though not quite as common), or from mother to child during birth

HIV is, of course, the disease that leads to AIDS. The bullet-shaped virus can be transmitted through blood, semen, pre-ejaculate, vaginal fluid, or breast milk, but cannot be transmitted through saliva. In 2013, 42,181 cases of HIV were reported, but the CDC estimates that the true number of cases is closer to 48,893.

Symptoms: There are three stages of HIV. The first is the acute stage, which develops within two to four weeks of infection. During this stage, the virus multiplies and attacks CD4 cells, which play an important role in the body’s ability to protect against a wide variety of infections. Patients will feel flu-like symptoms, including fever and headache. The second is the chronic stage, in which the symptoms disappear but the virus continues replicating itself. Untreated, it usually takes 10 to 12 years before the disease progresses to the third stage: AIDS. A patient is diagnosed with AIDS when his or her CD4 cell count reaches less than 200 cells per cubic millimeter. Due to a weakened immune system, the body cannot fight off infections and cancer. Without treatment, AIDS patients survive about three years.

Treatment: As you probably know, there is no cure for HIV. However, antiretroviral (ARV) drugs keep HIV from multiplying. Most patients who have access to HIV drugs take a combination of three different ARVs.