Why are Syphilis Cases on the Rise?

5 min read  |  March 14, 2024  | 

Syphilis, the sexually transmitted disease once nearly eliminated from the U.S., has seen an alarming increase among every age group. This is a worrisome trend for public health officials and infectious disease doctors who had thought it was under control thanks to antibiotics.

In 2022, new cases of this bacterial infection reached a rate not seen since 1950, according to the Centers for Disease Control and Prevention (CDC). Though most common in gay and bisexual men, new syphilis cases have jumped among women and heterosexual men. Cases of maternal syphilis alone — passed from mom to infant — more than tripled from 2016 to 2022, jumping from 87.2 to 280.4 per 100,000 births. 

These numbers do not surprise Laura Beauchamps, M.D., an infectious disease expert at the University of Miami Health System who specializes in sexually transmitted infection (STI) treatment in vulnerable populations as well as comprehensive HIV care and prevention. She’s seen more cases in both UHealth’s Rapid Access Wellness Clinic and its mobile unit during the past few years.

“We have young and middle-aged women and men coming to the clinic, and they don’t even know what syphilis is,” she says. “And so many young adults are simply not using condoms, which can help protect them.”

Nationally, the rate of all types of syphilis has skyrocketed by 17% from 2021 to 2022. 

In comparison, gonorrhea decreased by 8.7% while the rate of new chlamydia cases remained the same. Florida was ranked 17th in the rate of syphilis cases per 100,000, with South Dakota topping the list. In congenital syphilis (spread from mother to infant), Florida ranked 14th.

The rise has prompted the CDC to sound the alarm, stating that there is “an urgent need for swift innovation and collaboration from all STI prevention partners.” In response, the Department of Health and Human Services (HHS) has formed a national task force to address the resurgence.

Experts haven’t pinpointed the cause of the increase in syphilis. Still, Dr. Beauchamps believes it may be due to several causes: lack of awareness, continuing social stigma, characteristics of the disease that allow it to remain dormant and evade our immune system, and the decrease in condom use. The rise in drug addiction may also play a role.

“It’s frustrating because syphilis is very treatable,” she says. “Unlike other STIs that have developed resistance to antibiotics over the years, such as gonorrhea, penicillin still works with syphilis.”

In fact, syphilis infections began to drop steadily in the 1940s as antibiotics came on the market. They fell to their lowest rate by the late 1990s.

Unfortunately, the increase in syphilis cases has resulted in a shortage of Penicillin benzathine (Bicillin L-A) for treatment, forcing doctors to use alternative oral treatments (doxycycline Bicillin L-A), Dr. Beauchamps adds.

Syphilis is caused by bacteria, and it is spread when a person comes into contact with an infected person’s telltale sores. 

A mother can also pass it on to her baby during pregnancy and childbirth. “The spread,” adds Dr. Beauchamps, “is not limited to intercourse, to penetration. It can also happen through oral sex.” For example, some syphilis patients contract the bacteria — Treponema pallidum — by kissing or touching a sore that may be on the breasts, genitals or lips.

Nevertheless, “practicing safe sex is still the best prevention,” Dr. Beauchamps says. This includes abstinence, an exclusive long-term relationship with only one partner, and getting tested for STIs before having sex with a new partner. Condoms also lower the risk of getting syphilis — but work only if they cover an infected person’s sores.

The first sign of the disease is usually a sore, called a chancre, in the genitals, mouth, or rectum. 

This chancre is typically painless and tends to disappear in about three to six weeks, sometimes without even being noticed. However, the bacteria that causes the disease stays in the system and can become active later.

In the secondary stage, after the chancre has healed, syphilis can manifest itself as a rough, red, or reddish-brown rash that usually begins on the trunk of the body or on the limbs, the palms of the hands, or the soles of the feet. A person with secondary syphilis may also experience fever, muscle aches, a sore throat, fatigue, weight loss, and swollen lymph nodes. The individual may also have sores in the mouth or genital area.

Left untreated, the late stages of syphilis can damage the brain and the heart and cause blindness, deafness, and even paralysis. 

Late syphilis can reactivate and turn into infective disease (secondary syphilis), which is driving new cases of syphilis infection. In pregnant women, it can lead to miscarriage or stillbirth. In surviving infants, it can cause developmental delays or disabilities. What’s more, people with syphilis are at a higher risk of contracting HIV.

That said, there is also a post-exposure prophylactic named DoxyPEP that has been shown to lower the risk of contracting syphilis (and other sexually transmitted infections, though not HIV) by as much as 40%. It involves an oral 30-capsule regimen of doxycycline after sex to help prevent syphilis, chlamydia and even gonorrhea.

Dr. Beauchamps hopes that the attention now being paid to surging syphilis cases might result in more research into the fields of diagnostic testing and vaccines. 

“We also need to promote education on how syphilis is transmitted and how it can present and how it can mimic other diseases.”

If you think you might have contracted syphilis or another STI, contact UHealth’s Rapid Access Wellness Clinic at 305-243-2584. The clinic and its mobile unit offer prevention, treatment and counseling. For more information, visit UHealth’s Rapid Access Wellness Clinic.

Headshot of Ana Veciana, author (2023)

Ana Veciana-Suarez is a regular contributor to the University of Miami Health System. She is a renowned journalist and author who has worked at The Miami Herald, The Miami News, and The Palm Beach Post. Visit her website at or follow @AnaVeciana on Twitter.


CDC stats:

Tags: disease spread, Dr. Laura Beauchamps, infections, RAW clinic

Continue Reading