Syphilis Cases in Michigan Are Surging. Here’s Why.
James Grant, M.D.
| 5 min read
James D. Grant, M.D., is executive vice president an...
In the 1990s, syphilis cases were so low in the United States that the disease seemed to be on the brink of eradication. But multiple factors have led to a resurgence in cases, particularly in the last 10 years.
In Michigan, preliminary 2025 data show that rates of symptomatic and infectious syphilis have increased 50% over the past 10 years according to recent data from the Michigan Department of Health and Human Services (MDHHS). This new data comes on the heels of syphilis cases doubling in the state between 2017 and 2022.
This pattern reflects national trends, as 190,242 cases of syphilis were reported in the U.S. in 2024, per the United States Centers for Disease Control and Prevention (CDC). That marks a 42% increase since 2020.
Medical experts believe cases started spiking in the late 2010s because of a change in the epidemiology of the infection. Syphilis used to predominantly circulate in communities of gay and bisexual men, but the proportion of syphilis cases among straight men and women has risen rapidly.
What is syphilis?
Syphilis is a highly contagious sexually transmitted infection (STI), most often spread through unprotected sex. If left untreated, syphilis can affect one’s organs and nervous system, and increase the risk of acquiring other STIs, including HIV, per the MDHHS. The CDC reported a 90% rise in STIs between 2004 and 2023.
Syphilis can also be transmitted congenitally, when a mother with the disease passes the infection on to her baby during pregnancy, and the MDHHS states there has also has been a rise in congenital syphilis.
If left untreated, congenital syphilis this can lead to serious health complications for the baby, including death. There were 58 congenital syphilis cases reported in 2024, which was the highest total number of cases in Michigan in more than 30 years.
Why are cases increasing in Michigan?
Multiple factors contribute to the increase in syphilis cases, including:
- COVID-19 pandemic-related disruptions to testing, screening and prevention, including a spike in cases during the pandemic.
- Insufficient prenatal health care (specifically in the case of more babies being born with syphilis infection).
- A rise in latent syphilis infections, which represents a broad category of cases where the disease is discovered long after exposure and can appear without outward symptoms, according to Bridge Michigan. Latent cases reached a 10-year high in 2025, when 2,183 cases were reported in Michigan.
According to the MDHSS, the number of primary and secondary cases among Michigan residents who report only heterosexual sex more than doubled between 2013 and 2022, increasing from 19% to 48%.
And since 2019, congenital syphilis births in Michigan have increased more than 200%. Syphilis rates have also drastically increased for those ages 20-45 and in heterosexual people.
What are the four stages of syphilis?
The first, or primary, stage of syphilis is characterized by sores around the mouth or genital region, left by syphilis’ entrance into the body. These sores – which are typically painless – usually heal within three to six weeks, whether a person receives treatment or not.
The secondary stage occurs in those who do not receive treatment. The infection evolves into skin rashes, typically on the palms of your hands and bottoms of your feet, and mucous membrane lesions. Per the CDC, this stage can result in:
- A sore throat
- Fatigue
- Fevers
- Headaches
- Muscle aches
- Patchy hair loss
- Swollen lymph nodes
- Weight loss
The third, or latent, stage is marked by showing no physical signs or symptoms of syphilis, but still being able to transmit it. This stage can last for years, according to the CDC.
Most people do not develop the fourth, or tertiary stage of syphilis. For those that do, this is a serious condition that can affect many systems in the body and can occur many years after the infection began.
Testing and treatment options for syphilis
Getting tested for syphilis is important, especially for pregnant women. All sexually active people are encouraged to ask for a syphilis blood test when getting tested for other STIs like:
- Gonorrhea
- Chlamydia
- HIV
Most local health departments offer no or low-cost testing and many medical providers can order this test. Most syphilis cases are relatively easy to treat, but not all affected communities have access to health care, particularly prenatal care. Here is a Michigan.gov list of STI clinics in the state, most of which test and treat syphilis. If they do not, it is otherwise noted.
If caught in time, syphilis is treatable and curable. Penicillin is still the most effective antibiotic for treating syphilis. However, challenges can arise even after an infection is diagnosed.
In April 2023, the Food and Drug Administration (FDA) reported a shortage in bicillin, also known as penicillin G. Then in January 2024, the FDA approved the temporary importation of Extencilline, a bicillin equivalent distributed in other countries, to help offset the shortage.
Speak with your primary care provider to discuss available treatment options, as well as which options are best for you based on your health profile.
James D. Grant, M.D., is senior vice president and chief medical officer at Blue Cross Blue Shield of Michigan.
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