The word “syphilis” may conjure up images of a disease afflicting Europeans starting around the end of the 15th century, an era where it caused significant illness and sometimes death. But syphilis is still around, especially in New Mexico, which only a few years ago ranked second in the nation for primary and secondary syphilis and congenital syphilis, according to the New Mexico Department of Health (NMDOH).

Syphilis needs to be taken seriously, said Meghan Brett, MD, a professor of infectious diseases in The University of New Mexico School of Medicine and the hospital epidemiologist at UNM Hospital.

“Syphilis is not a thing of the past,” she said. “It’s present and it can lead to lots of complications.”

Syphilis is a sexually transmitted bacterial infection that can cause a range of symptoms, from a painless ulcer to much more severe issues such as stroke and blindness, if left untreated. In addition to affecting individuals, syphilis can spread from a mother to a fetus during pregnancy, a condition known as congenital syphilis.

To reduce the chance of getting syphilis and other sexually transmitted infections (STIs), Brett recommends people practice safe sex with a condom. And, anyone who is sexually active should take advantage of STI testing and seek treatment for a confirmed infection, she said.

Syphilis by the Numbers

From 2015 to 2023, the rates of primary syphilis (ulcer) and secondary syphilis (widespread symptoms, often with a rash) in New Mexico increased overall, according to the NMDOH report “New Mexico STD Program Summary of Surveillance Data: 2025”. Also according to the report:

• In 2023, the rates of primary and secondary syphilis in New Mexico peaked at 36.5 cases per 100,000 people, placing the state No. 2 in the nation that year.
• That case rate then declined for two years in a row, down to 14.8 per 100,000 people in 2025.
• The rate of congenital syphilis in New Mexico rose substantially from 2017 to 2023, peaking in 2023 at 445.6 cases per 100,000 live births. New Mexico placed No. 2 in the U.S. for congenital syphilis in 2023.
• That rate declined for the next two years, down to 311.6 cases per 100,000 live births in 2025.

“What’s great is that we have made progress, but rates are still substantially higher than they were 10 years prior,” Brett said.

Syphilis Symptoms and Consequences

Syphilis can cause a variety of symptoms, including a painless ulcer or a distinctive whole-body rash. And, syphilis can cause worse problems if the bacteria invade important parts of the body, such as the brain or eyes, Brett said.

“The other concerns about syphilis are the fact that it can affect your brain and the fluid around your brain, as well, leading to neurosyphilis,” she said. “It can also impact people’s eyes and their vision, because the spirochetes, which are the type of bacteria that cause the infection, can go just about anywhere.”

Not all syphilis infections cause symptoms, but they may still cause problems, Brett said.

“There can be complications down the line if people do not get treatment for syphilis,” she said. “For example, it can actually lead to later stages of infection that can affect people’s brain and nerves. That’s why it’s really important to get treatment sooner rather than later.”

Congenital syphilis — where a pregnant woman passes the infection to her baby — can cause its own problems for a developing fetus or newborn baby.

“What happens is that infection can infect the fetus, and that has lots of consequences for the baby after birth,” Brett said.

According to the U.S. Centers for Disease Control and Prevention (CDC), congenital syphilis can cause complications including miscarriage, stillbirth, premature birth and more. Babies born with congenital syphilis are at risk of dying, or they might have deformed bones, severe anemia, enlarged liver and spleen or other problems, the CDC reports.

 

There are different types of treatment depending on the stage of syphilis. It’s really important for people to get the right follow-up on the right treatment to protect against the consequences of syphilis infection. And, certainly, if people are pregnant, then treatment is even more important to prevent complications, not only for the pregnant patient, but also for the fetus, as well.

 

 

- Meghan Brett, MD, Professor of Infectious Diseases, UNM School of Medicine & Hospital Epidemiologist, UNM Hospital

Syphilis Testing and Treatment

Fortunately, syphilis is detectable through blood testing and can be treated — and cured — with antibiotics.

Brett advises anyone with syphilis symptoms to visit a healthcare provider. Or, they can visit one of NMDOH’s Public Health Offices, located around the state, which provide testing and treatment for STIs, she said.

Brett recommends that people who are sexually active be tested at least once for syphilis.

“If people are having sex and have never been tested, then now’s a better time than any to go get tested,” she said. “If people have challenges with using substances, or have multiple sex partners and are not using protection — that’s a group that I’d recommend getting tested more frequently.”

Pregnant patients need to be screened as well, due to the potential risks of congenital syphilis, Brett said. NMDOH released specific guidelines in October 2026 for when pregnant patients should be tested.

Getting tested is only the beginning. There are multiple treatment options for syphilis, but treatment requires monitoring by a healthcare provider, Brett said. Depending on what part of the body the disease is affecting (such as the brain or the eyes), treatment might require two weeks of IV antibiotics.

“For providers who are treating patients with syphilis, please ask for help and guidance when it’s not clear,” Brett said. “There are different types of treatment depending on the stage of syphilis. It’s really important for people to get the right follow-up on the right treatment to protect against the consequences of syphilis infection. And, certainly, if people are pregnant, then treatment is even more important to prevent complications, not only for the pregnant patient, but also for the fetus, as well.”

Common treatments for syphilis include antibiotics such as penicillin and doxycycline, Brett said. If someone has an allergy to penicillin, she said there still may be other options for treatment.

“What we can do is assess the type of reaction, and then if it’s anaphylaxis — which is a severe, specific kind of reaction — we can actually desensitize people to penicillin so they can get penicillin treatment,” Brett said. “I think a lot of people report penicillin allergies, but when you do a deeper dive, it turns out not to be anaphylaxis.”

At the end of the day, Brett said people shouldn’t be ashamed if they get a syphilis diagnosis.

“If people are sexually active, syphilis still happens,” she said. “I just think it’s really important to get tested and if positive, treatment — there’s effective treatment.”