Some diseases fade away. Others seem to do that, but then come roaring back. That’s what has happened with syphilis, especially congenital syphilis, a sexually transmitted infection passed from mother to child.
When I became a public health physician in 2007, congenital syphilis was something I had read about but never seen. Today, consulting on cases of it has become routine; my colleagues and I at the California Prevention Training Center received more than 100 requests for consultations about congenital syphilis in 2019 and 2020. An April 2021 report from the Centers for Disease Control and Prevention confirms this disturbing trend nationwide. In 2019, the last year with complete data, there were 1,870 cases of congenital syphilis in the U.S., a 300% increase over the past five years.
Though congenital cases are just fraction of the country’s approximately 130,000 cases of syphilis, it’s spiraling out of control, surpassing the peak of mother-to-child transmissions of HIV at the height of the AIDS crisis.
Infants infected with HIV appear to be normal and healthy. Those born with syphilis, in contrast, can have skeletal and facial deformities, as well as deafness and blindness, and up to 40% of those with congenital syphilis are stillborn or die early. These deaths and physical problems are preventable tragedies: Testing is cheap and widely available, and treatment with antibiotics is highly effective. Every case is a sentinel event, signaling holes in the health care safety net that must be addressed with the same urgency as the perinatal HIV epidemic 30 years ago.
Most physicians of my generation emerged from medical training unaware of syphilis. Two decades ago, this sexually transmitted infection had reached a nadir — 80% of U.S. counties reported zero cases in 1999. Capitalizing on this “narrow window of opportunity” the CDC launched an elimination campaign, the third such attempt in the agency’s history. As rates dipped lower the following year, it seemed that Y2K would usher in a syphilis-free millennium, and public health officials were poised to pop the champagne.
But though we thought we were done with syphilis, syphilis was just getting started with us. Fueled by waning fear of HIV coupled with the rise of internet hookups, cases began to creep up in 2001.
Despite laws in most states requiring prenatal screening for syphilis and HIV with blood antibody tests, the curves of these two infections began to diverge. HIV in newborns plummeted from 1,760 cases in 1991 to 39 cases in 2018. Meanwhile, congenital syphilis cases soared, with 43 states reporting cases in 2019; Texas and California vied to be the best of the worst, accounting for half of all U.S. cases.
Pregnant people affected by syphilis and HIV reside in overlapping Venn diagrams. They tend to be people of color struggling with poverty, homelessness, substance use, or incarceration. Yet while eleventh-hour interventions such as antiretroviral therapy can prevent mother-to-child transmission of HIV, it’s not so easy to prevent transmission of syphilis, which requires one to three weekly penicillin injections delivered at least a month before delivery. Many pregnant people fall through the cracks here: One-third of congenital cases occur because the mother is not adequately treated before delivery. One in four get prenatal care only late in their pregnancies or no care at all until the onset of labor, missing the window to prevent congenital syphilis and its consequences.
Bending the curve of syphilis transmission will take a robust, coordinated prevention plan. A road map to guide this effort is the Department of Health and Human Services’ first Sexually Transmitted Infections National Strategic Plan, which went into effect in January 2021. Its five-year goals include reducing the rate of congenital syphilis by 15%, and lowering disparities among Black, Hispanic, and Native American babies, who are three to six times more likely to suffer from congenital syphilis than white infants.
More funding will be needed to get there. Until now, sexually transmitted infections like syphilis and gonorrhea have been HIV’s poor cousins: CDC funding for them has stalled out at approximately $160 million per year for nearly two decades compared to routine increases for HIV, with funding for it reaching $964 million in FY 2021.
The public health response to congenital syphilis must address lapses in maternal screening and treatment, which states are attempting through increasing the frequency of prenatal screening or deploying contact tracers to deliver penicillin to clinics so pregnant people with syphilis are given timely treatment. Clinicians also need additional anti-syphilis therapies, as the fragile supply chain for injectable penicillin makes it vulnerable to shortages.
Health departments will need to get creative in their outreach to pregnant people who don’t seek out prenatal care. In western states, where one-third of women with syphilis use methamphetamine or opioids, integrating public health efforts for sexually transmitted infection programs and substance use programs will be essential to ensure success.
The Covid-19 pandemic may inadvertently help the U.S. public health system get where it needs to go. The pandemic brought an influx of funding to health departments to modernize infrastructure and expand the contact tracing workforce. Once the end of the pandemic is in sight, it will be essential to maintain gains in staffing and pivot efforts back toward the epidemic of sexually transmitted infections and other ills that went neglected while the pandemic consumed the country’s attention.
Those of us in public health would also be wise to learn from the successes of the past. If HIV/AIDS has taught us anything, it’s that ending mother-to-child transmission of infectious diseases is achievable when health care workers and public health experts have the tools for prevention and the political will to use them. HHS must honor its commitment to the federal Sexually Transmitted Infections National Strategic Plan, fight the scourge of congenital syphilis, and provide all infants born in the U.S. the healthy starts in life they deserve.
Ina Park is a public health physician, medical director of the California Prevention Training Center at the University of California San Francisco, and author of “Strange Bedfellows: Adventures in the Science, History, and Surprising Secrets of STDs” (Flatiron Books, 2021).