Syphilis on rise in Michigan newborns as some adult cases decline

Michigan reported 691 primary and secondary syphilis cases in 2024, down from its COVID-19 peak
Congenital syphilis increased 38% since 2021, with an estimated 50-60 newborns testing positive this year
Preventive antibiotic treatment and increased screenings are helping drive down the number of cases in Metro Detroit

Michigan health officials are cautiously optimistic about a reduction in primary and secondary stage syphilis infections in the state, while they continue to monitor increased cases of the sexually transmitted infection as it’s passed down to newborns.

The Michigan Department of Health and Human Services says cases of primary and secondary stage syphilis, which occurs in individuals within six months of exposure, fell from a peak of 980 statewide in 2021 to 691 in 2024.

Despite a declining trend in primary and secondary syphilis, the state is seeing an upward trend of congenital syphilis, which has increased 38% since 2021. MDHHS estimates between 50 and 60 births this year will test positive for syphilis.

In addition, latent syphilis, which represents a broad category of cases where the disease is discovered long after exposure and can appear without outward symptoms, has hit a 10-year high, with 2,183 cases reported in Michigan last year.

Dr. Natasha Bagdasarian, Michigan’s chief medical executive, said she was “encouraged” to see the drop in recent syphilis infections, attributing the reduction to strategies like the Michigan’s “Stop Syphilis” campaign along with stronger partnerships with clinicians and social service agencies that have improved screening and treatment.

“But these numbers also highlight the continued urgency of our work, especially around congenital syphilis,” Bagdasarian said in a statement. “Every case represents an opportunity to do more, and we remain committed to protecting the health of all Michiganders.”

STI ‘explosion’ during COVID-19

Syphilis has seen a resurgence in the US since the turn of the century, along with chlamydia and gonorrhea. Last November, the US Centers for Disease Control and Prevention reported a 90% rise in STIs between 2004 and 2023.

More than 209,000 cases of syphilis were reported in 2023 — the nation’s highest levels in more than 70 years. Congenital syphilis has similarly reached its highest levels since 1992, with the CDC reporting 3,882 cases that year.

Physicians and public health experts say many factors are driving the recent increased spread of STIs, including inadequate screening, lack of access to health care and the closure of treatment centers.

Dr. Eric McGrath, a pediatrician who specializes in infectious diseases, said he saw an “explosion” of cases during and after the onset of the COVID-19 pandemic at his clinic in Detroit.

“Even when the restrictions were all lifted, some people were still very nervous to go back to medical care,” McGrath told Bridge Michigan.

Routine prenatal care when pregnant people are screened for common infectious diseases can lead to treatment before a child’s birth. Syphilis can be cured with antibiotics like penicillin.

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But relying solely on the screening and treatment of expecting mothers, McGrath said, might not be enough to stop the sexual spread of the disease.

“If mom was tested and treated but then the father wasn’t, and they continue to be (sexually) active with the father, they can actually get reinfection,” said McGrath. “I actually think that’s one of the main reasons why we don’t see less and less congenital syphilis, even though the state’s been putting a huge focus on it.”

McGrath said newborns that contract syphilis have to stay in the neonatal intensive care unit up to two weeks, receiving blood tests and spinal taps as they receive penicillin treatment.

“This is something that really interrupts bonding,” he said, adding that syphilis can also cause stillbirths and infant death. If left untreated, children can develop a perpetually runny nose in a condition known as “snuffles” and bone abnormalities.

“The sad thing is that it probably is nearly completely preventable.”

Doxy PEP drives down cases

Detroit carries much of Michigan’s syphilis burden, representing about a third of the state’s overall cases. The city has seen significant decreases with 182 cases reported in 2024, down from 327 the year prior.

“With the exception of occasional outbreaks that occur elsewhere, most syphilis, just like most STIs, is concentrated in urban areas … where there are denser sexual networks,” said Dr. Gretchen Newman, director of Wayne State University’s Adult HIV Program.

“It’s almost certainly not due to differences in behavior between rural people and urban people,” she added.

Metro Detroit has made strides in preventing STIs, Newman said, through promoting the treatment regimen doxycycline post-exposure prophylaxis, or doxy PEP. Recent research shows a significant reduction in STIs among men who have sex with men when they take doxycycline within 72 hours of sex.

“This is the first biomedical intervention for syphilis, chlamydia and gonorrhea that, truthfully, we have ever had on the prevention side,” Newman said, adding there is “crossover” between sexual networks which can drive exposure between groups.

Gay and bisexual men and transgender women are disproportionately affected by syphilis nationally, and the state reports Michigan’s Black population represents 52% of reported STIs despite making up 14% of the state’s population.

MDHHS notes that while recent syphilis cases dropped sharpest in Southeast Michigan, there were more cases reported in Jackson and Muskegon counties. The department says it has a $8.6 million appropriation to address STIs across the state, with 22 disease intervention specialists that follow up on reported cases.

Treatment sites for STIs like syphilis can be found at this CDC link here.

Michigan’s HIV and STI Hotline operates Monday through Friday, 9 a.m. to 5 p.m. at 800-872-2437 and Michigan’s 2-1-1 information line operates 24 hours a day.