The Resurgence of Maternal and Congenital Syphilis in the United States: A Surveillance Analysis, 2022–2024

Abstract

The United States is currently witnessing a precipitous and alarming resurgence of syphilis, a sexually transmitted infection (STI) once thought to be on the verge of elimination. This report provides an exhaustive examination of the escalating crisis of maternal and congenital syphilis, anchored by the most recent surveillance data from the National Center for Health Statistics (NCHS) covering the period from 2022 to 2024. During this two-year window, the rate of maternal syphilis—defined as live births to women with syphilis—increased by 28%.¹ This surge acts as a bellwether for the broader failure of public health infrastructure, revealing deep fissures in the nation’s healthcare safety net, particularly for Indigenous, Black, and rural populations. This analysis explores the epidemiological trends, the unique pathophysiology of vertical transmission, the "syndemic" drivers such as methamphetamine use and housing instability, and the critical fragility of the treatment supply chain. It concludes with a critical evaluation of evolving screening guidelines and the urgent need for structural interventions to stem the tide of preventable neonatal morbidity and mortality.

Introduction: The Return of the Great Pox

For much of the late 20th century, the narrative of syphilis in the developed world was one of triumph. Following the discovery of penicillin and the implementation of rigorous public health tracking, rates of Treponema pallidum infection plummeted. By 1999, the Centers for Disease Control and Prevention (CDC) had launched a national plan to eliminate syphilis, buoyed by historically low case counts. The medical community began to view congenital syphilis—the vertical transmission of the disease from mother to fetus—as a relic of a bygone era, a "never event" that should not occur in a modern healthcare system equipped with effective diagnostics and a curative antibiotic.

However, the past decade has dismantled this optimism. The "Great Imitator," so named for its ability to clinically mimic a vast array of other pathologies, has returned with vengeance. The resurgence is not merely a statistical blip but a sustained epidemiological failure. The latest data released by the CDC’s National Center for Health Statistics (NCHS) in early 2026 paints a grim picture: the maternal syphilis rate in the United States continues to climb aggressively, rising 16% from 2022 to 2023 and another 10% from 2023 to 2024.¹

This report aims to dissect the layers of this crisis. It is not enough to simply catalog the rise in numbers; one must understand the why and the how. Why, in an era of advanced genomic medicine, are we failing to treat an infection curable with a drug discovered in 1928? How does the biology of Treponema pallidum exploit the social vulnerabilities of the American populace? And what are the long-term consequences for the generation of infants currently being born into this epidemic?

The analysis that follows is grounded in a deep review of surveillance reports, clinical studies, and policy documents. It serves as a comprehensive record of a public health emergency that is unfolding in real-time, disproportionately affecting the most marginalized communities in the nation.

Section I: The Epidemiological Landscape (2022–2024)

The statistical trajectory of syphilis in the United States over the last few years indicates a compounding crisis. While other sexually transmitted infections such as chlamydia and gonorrhea have shown signs of stabilizing or even declining in recent provisional data sets ³, syphilis has decoupled from these trends, continuing an unrelenting upward march.

The Velocity of the Surge

The core metric of concern is the maternal syphilis rate. This rate serves as the most direct predictor of congenital syphilis cases; biologically, an infant cannot contract congenital syphilis unless the mother is infected. According to the NCHS Health E-Stat 110 report, the rate of maternal syphilis for the entire United States rose from 280.4 per 100,000 births in 2022 to 357.9 per 100,000 births in 2024.¹

This 28% increase over two years is significant not only for its magnitude but for its persistence. It follows a dramatic 222% increase observed from 2016 to 2022, suggesting that despite heightened awareness and public health alerts, the transmission dynamics are accelerating rather than slowing.²

• 2022 Rate: 280.4 per 100,000 births

• 2023 Rate: 324.6 per 100,000 births (16% increase year-over-year)

• 2024 Rate: 357.9 per 100,000 births (10% increase year-over-year)

• Cumulative Increase (2022–2024): 28% ¹

This continued surge has driven the number of congenital syphilis cases to levels unseen since the early 1990s. In 2023, there were 3,882 reported cases of congenital syphilis, including 279 syphilitic stillbirths and infant deaths.⁵ Provisional data for 2024 indicates the number of cases has approached 4,000, marking the 12th consecutive year of increases.³ This relentless rise underscores the inadequacy of current control measures.

Demographic Disparities: The Burden of Inequality

The aggregate national data masks the profound and widening disparities that exist across racial and ethnic lines. The syphilis epidemic in the United States is not a generalized phenomenon but is heavily concentrated in populations that have been historically marginalized and structurally disadvantaged.

The Catastrophe in Indigenous Communities

The most distressing data point in the 2022–2024 analysis is the explosion of cases among American Indian and Alaska Native (AI/AN) mothers. This demographic has consistently had the highest rates of maternal syphilis, but the acceleration in recent years is catastrophic.

In 2022, the rate for AI/AN mothers was 1,410.5 per 100,000 births—already five times the national average. By 2024, this rate had skyrocketed to 2,145.4 per 100,000 births, representing a 52% increase in just two years.¹

Table 1: Maternal Syphilis Rates by Race and Hispanic Origin (2022–2024)

Race and Hispanic Origin	2022 Rate (per 100,000 births)	2023 Rate (per 100,000 births)	2024 Rate (per 100,000 births)	Total % Increase (2022–2024)
All Races (Total)	280.4	324.6	357.9	28%
American Indian / Alaska Native	1,410.5	2,052.9	2,145.4	52%
Black, non-Hispanic	684.7	786.6	887.6	30%
Hispanic	313.8	358.7	411.1	31%
White, non-Hispanic	152.8	174.4	188.2	23%
Asian, non-Hispanic	73.3	80.0	68.9	No significant change
Native Hawaiian / Pacific Islander	713.4	932.8	1,004.9	No significant change

Source: CDC/NCHS Health E-Stat 110 ¹

This 52% increase among AI/AN populations highlights a critical failure of the Indian Health Service (IHS) and tribal health infrastructures, which have been chronically underfunded. It also points to the intersection of geographic isolation and limited access to culturally competent prenatal care.

Disparities Among Black and Hispanic Mothers

Black non-Hispanic mothers continue to bear a disproportionate burden of the epidemic. The rate for this group rose 30% from 684.7 in 2022 to 887.6 in 2024.¹ This persistent disparity is rooted in systemic racism, which influences social determinants of health such as housing stability, incarceration rates, and access to quality healthcare.

Hispanic mothers also saw a significant increase of 31%, rising from 313.8 to 411.1 per 100,000 births.¹ This increase was sharper than that observed in White mothers (23%), suggesting that language barriers and fears related to immigration status may be deterring Hispanic women from seeking early prenatal care.

Age-Related Trends: A Shift Toward Older Mothers

While the absolute rates of maternal syphilis remain highest among younger women, the rate of increase is accelerating most rapidly among older mothers. Mothers under the age of 20 and those aged 20–24 had the highest rates in 2024 (474.2 and 514.3, respectively), but the growth in these groups was 13% and 29% respectively.¹

In contrast, the rate rose 36% for mothers aged 35–39 and 31% for mothers aged 40 and older.¹ This shift is clinically significant because providers may perceive older mothers as being at "lower risk" for STIs compared to adolescents. This bias can lead to less rigorous screening or a lower index of suspicion when symptoms present, resulting in missed diagnoses.

Section II: The Geography of Infection — A Rural Shift

Historically, syphilis in the United States was concentrated in urban centers, associated with high population density and specific sexual networks. However, the data from 2016 to 2023 reveals a profound transformation in the geography of the epidemic. The epicenter is drifting from the inner city to rural America.

The Urban-Rural Crossover

A comparative analysis of maternal syphilis rates indicates that since 2021, rural rates have exceeded urban rates.⁸ While rates in urban areas tripled from 2016 to 2023, rates in rural areas quintupled over the same period.⁸

This "ruralization" of syphilis presents unique and formidable challenges for public health intervention. Rural America is currently facing a crisis of healthcare access often described as "maternity care deserts." In these regions, hospitals have closed obstetrics units due to financial unsustainability, leaving vast geographic areas without accessible prenatal care.⁹ A pregnant woman in a rural county may have to drive several hours to reach a provider. This logistical barrier often leads to delayed entry into prenatal care or missed appointments, which in the context of syphilis, can be fatal for the fetus.

State-Level Burdens

The geographic dispersion of the epidemic is evident in the state-level rankings for congenital syphilis rates. In 2023, the states with the highest rates were not the dense urban states of the Northeast, but rather states with large rural populations and significant Indigenous communities.

Table 2: Top 10 States with Highest Congenital Syphilis Rates (2023)

Rank	State	Cases	Rate per 100,000 Live Births
1	South Dakota	54	482.1
2	New Mexico	91	421.0
3	Mississippi	131	377.8
4	Arizona	233	296.6
5	Texas	930	238.6
6	Nevada	77	232.0
7	Louisiana	109	193.0
8	Arkansas	64	180.4
9	Montana	19	170.0
10	Oklahoma	79	163.5

Source: CDC STI Surveillance Report 2023 ⁶

South Dakota's rate of 482.1 per 100,000 live births is staggeringly high—more than four times the national average of 105.8.⁶ This figure is heavily influenced by the outbreak among AI/AN populations in the Plains states. Similarly, the high rates in New Mexico, Arizona, and Oklahoma reflect the intersection of rural healthcare gaps and the disproportionate impact on Indigenous communities.⁸ The presence of Mississippi, Louisiana, and Arkansas in the top ten underscores the entrenched nature of the epidemic in the Deep South, where poverty and lack of Medicaid expansion in some areas exacerbate health outcomes.

Section III: The Pathophysiology of Vertical Transmission

To understand the urgency of the maternal syphilis crisis, it is necessary to look beyond the surveillance statistics to the biological reality of the infection. Treponema pallidum is a spirochete bacterium with a distinct and terrifying capability to traverse the placental barrier, a feat that many other bacteria cannot accomplish.

The Mechanism of Placental Invasion

Vertical transmission of syphilis occurs when spirochetes in the maternal bloodstream invade the placenta and subsequently infect the fetus. Recent research has shed light on the molecular mechanisms that facilitate this invasion. A key virulence factor identified is the Tp0954 protein, a surface lipoprotein of T. pallidum.¹¹

Studies utilizing placental cell lines (such as BeWo cells) have demonstrated that Tp0954 facilitates the adherence of the spirochete to placental tissue. It appears to bind to heparan sulfate and dermatan sulfate, glycosaminoglycans found in the extracellular matrix of the placenta.¹² This binding allows the bacteria to colonize the intervillous spaces and breach the syncytiotrophoblast layer, the primary barrier between maternal blood and fetal tissue.

Once the placenta is infected, the immune response creates a specific pathology known as necrotizing funisitis. This condition is characterized by a severe, deep-seated inflammation of the umbilical cord involving necrosis of the Wharton’s jelly and the vessel walls.¹³ Necrotizing funisitis is highly specific to syphilis and represents a profound inflammatory reaction that can compromise fetal blood supply, leading to intrauterine growth restriction (IUGR) or fetal death.¹⁵ The inflammation also thickens the placenta (placentomegaly), impairing nutrient and oxygen transfer.

Gestational Age and Transmission Risk

The risk of transmission is not uniform throughout pregnancy; it is modulated by the stage of maternal infection and the gestational age.

• Primary and Secondary Syphilis: In these early stages of infection, the maternal bacterial load (spirochetemia) is highest. Consequently, the risk of transmission to the fetus is maximal, ranging from 70% to 100% in untreated cases.¹⁶

• Early Latent Syphilis: As the maternal immune system partially controls the infection and it enters the latent phase (asymptomatic but <1 year duration), transmission rates drop to approximately 40%.¹⁶

• Late Latent Syphilis: In infections persisting longer than a year, the risk decreases further to about 8%, though it is never zero.¹⁷

A critical misconception in historical obstetrics was the "Langhans layer theory," which posited that the spirochete could not cross the placenta before 18 weeks of gestation. Modern molecular detection methods have decisively disproven this, identifying T. pallidum in fetal tissues as early as 9 to 10 weeks.¹⁸ This biological fact emphasizes that there is no "safe window" in early pregnancy; infection can occur at any point, necessitating early and repeated screening.

Section IV: The Clinical Spectrum of Congenital Syphilis

The consequences of T. pallidum infection in a fetus are devastating and multifaceted. The clinical presentation is often divided into adverse pregnancy outcomes (stillbirth, miscarriage) and infection in the live-born infant.

Fetal Mortality

Syphilis is a leading cause of preventable stillbirth. Untreated syphilis in pregnancy results in adverse birth outcomes in 50% to 80% of cases.¹⁹ In 2023 alone, there were 279 reported syphilitic stillbirths and infant deaths in the United States.⁵ These deaths are often caused by severe fetal anemia, hydrops fetalis (accumulation of fluid in multiple fetal compartments due to heart failure), and placental insufficiency caused by the necrotizing inflammation described above.

Early Congenital Syphilis (<2 Years)

Infants born alive with the infection may appear asymptomatic at birth—a dangerous "silent" presentation that occurs in up to 60% of cases. Without treatment, symptoms typically emerge within the first few weeks or months.

• Hepatosphlenomegaly: Enlargement of the liver and spleen is a common early sign, often accompanied by jaundice and elevated liver enzymes.¹⁷

• "Snuffles": A persistent, copious nasal discharge that is heavily laden with spirochetes and highly infectious.

• Skin Rashes: A maculopapular rash that often involves the palms and soles and causes desquamation (peeling) of the skin.²⁰

• Bone Lesions: Osteochondritis and periostitis (inflammation of the bone and periosteum) are painful, leading to "pseudoparalysis of Parrot," where the infant refuses to move a limb due to pain.²¹

• Neurosyphilis: Invasion of the central nervous system can occur early, leading to meningitis, seizures, and developmental delays.²⁰

Late Congenital Syphilis (>2 Years)

If the infection remains untreated beyond infancy, it progresses to late congenital syphilis, a chronic inflammatory state that causes permanent disfigurement and disability. The classic signs, known as Hutchinson’s Triad, are pathognomonic:

1. Hutchinson’s Teeth: Incisors that are widely spaced and notched at the biting edge.²²

2. Interstitial Keratitis: Inflammation of the cornea that typically appears between ages 5 and 20, leading to pain, photophobia, and potential blindness.²¹

3. Sensorineural Deafness: Damage to the eighth cranial nerve, resulting in permanent hearing loss.²²

Other stigmata include the "saddle nose" deformity (collapse of the nasal bridge), "saber shins" (anterior bowing of the tibia), and Clutton's joints (painless swelling of the knees).²⁰ These physical manifestations are lifelong reminders of a preventable failure in prenatal care.

Section V: The Syndemic Drivers — Methamphetamine and Housing

The biological efficiency of T. pallidum is amplified by a fragile social canopy. The resurgence of maternal syphilis is not occurring in a vacuum; it is fueled by a syndemic—a clustering of two or more epidemics that interact synergistically to increase the burden of disease. In the current US context, the syphilis epidemic is inextricably linked to the methamphetamine crisis and the housing crisis.

The Syphilis-Methamphetamine Nexus

Substance use, particularly methamphetamine, has emerged as a primary driver of heterosexual syphilis transmission. Qualitative and quantitative studies have established a strong correlation. Methamphetamine is a stimulant that is associated with high-risk sexual behaviors, including decreased condom use, multiple partners, and transactional sex.²⁴ Furthermore, the physiological effects of the drug can lead to extended periods of arousal and abrasive sexual activity, which may facilitate the entry of the bacteria through micro-abrasions.

In a pivotal CDC study of congenital syphilis cases, infants with the condition were significantly more likely to be born to parents who used methamphetamine (46%) or whose partners used methamphetamine (33%) compared to non-CS infants.²⁴

Crucially, methamphetamine use creates a formidable barrier to prenatal care. Pregnant women who use drugs often fear legal repercussions, such as incarceration or the involvement of Child Protective Services (CPS). This fear drives them underground, leading to late or no prenatal care. A woman may avoid the doctor until she is in labor, at which point the opportunity to prevent congenital syphilis has been lost.

Homelessness and the Continuity of Care

Housing instability is another critical component of this syndemic. Data indicates that 23% of mothers delivering infants with congenital syphilis experienced homelessness, compared to only 10% of those with non-CS infants.²⁴

Homelessness disrupts the logistical chain required to treat syphilis effectively. The treatment for syphilis of unknown duration or late latent syphilis—which is the default diagnosis when a patient has no prior testing history—requires three doses of Benzathine Penicillin G spaced exactly one week apart.²⁵ For a woman living in a tent encampment, a shelter, or a car, adhering to a strict weekly appointment schedule is immensely difficult. Transportation issues, phone instability, and the daily struggle for survival often take precedence over medical appointments. If a dose is missed by more than a few days, the entire three-week series must be restarted.²⁵ This requirement leads to high rates of "treatment failure" not because the drug didn't work, but because the regimen could not be completed.

Section VI: The Screening Conundrum and "Missed Opportunities"

The CDC classifies congenital syphilis cases by "missed opportunities"—points in the healthcare cascade where intervention could have prevented the outcome but failed. In 2022, nearly 90% of congenital syphilis cases in the US were linked to such missed opportunities, primarily the lack of timely prenatal care or the lack of timely syphilis testing and treatment.²⁶

The 30-Day Rule

A critical clinical definition governs the prevention of congenital syphilis: maternal treatment must be completed at least 30 days before delivery to be considered adequate for the infant.²⁸ This rule exists because the clearance of the organism and the resolution of placental inflammation take time. If a woman is diagnosed and treated at 38 weeks gestation, even if she receives the correct dose of penicillin, her treatment is classified as "inadequate" for the infant because delivery is imminent. The infant must then be evaluated and treated as if they have congenital syphilis.³⁰ This 30-day biological window makes the timing of third-trimester screening absolutely critical; testing at delivery is too late to prevent the case, it only serves to identify the need for neonatal treatment.

The Shift from Risk-Based to Universal Screening (2024)

For years, guidelines recommended screening at the first prenatal visit, and then third-trimester screening only for women considered "high risk." However, the definition of "high risk" was subjective and often poorly applied by clinicians. Many providers underestimated the risk profile of their patients, or patients did not disclose sensitive behaviors like substance use or new partners. This led to a massive gap where women acquired syphilis during pregnancy but were not re-tested until delivery.

In response to the escalating rates and the failure of the risk-based approach, the American College of Obstetricians and Gynecologists (ACOG) issued a major practice advisory in April 2024. The new guidelines represent a paradigm shift to universal serial screening.

ACOG now recommends that all pregnant individuals be screened serologically for syphilis three times:

1. At the first prenatal care visit.

2. Universal rescreening during the third trimester (typically at 28 weeks).

3. At the time of admission for labor and birth.³¹

This universal approach aims to capture infections acquired during pregnancy regardless of the patient's perceived risk factors. By testing everyone at 28 weeks, the goal is to identify and treat infections before the critical 30-day pre-delivery window closes.

Section VII: The Treatment Crisis — Supply Chain Fragility

Compounding the biological and social crises is a logistical nightmare: a severe and prolonged shortage of the only drug effective for treating syphilis in pregnancy.

The Penicillin G Monopoly

Benzathine Penicillin G (marketed as Bicillin L-A) is the gold standard for treating syphilis. For pregnant women, it is the only option. Alternative antibiotics used in non-pregnant adults, such as doxycycline, are contraindicated in pregnancy due to risks of fetal tooth discoloration and inhibition of bone growth.³⁴

The supply of Bicillin L-A in the United States is fragile because it relies on a single manufacturer: Pfizer.³⁵ Since 2023, Pfizer has faced manufacturing constraints driven by the increased demand from the syphilis epidemic itself, creating a vicious cycle.

The Shortage Status (2023–2026)

As of January 2026, the FDA drug shortage database indicates that the supply of Bicillin L-A remains critically constrained. The pediatric 600,000 unit syringes are on backorder with an estimated release date of December 2026.³⁵ The adult 1.2 million and 2.4 million unit syringes are on "allocation," meaning Pfizer limits the amount sent to wholesalers to manage inventory.³⁶

This shortage has forced public health departments to make difficult ethical decisions regarding triage. Guidelines issued by state health departments (e.g., Virginia, New Mexico) explicitly prioritize pregnant women and infected infants for Bicillin L-A. They recommend that non-pregnant adults be treated with doxycycline instead to conserve the penicillin supply.³⁴

While this triage is medically sound, it adds friction to the system. A non-pregnant patient diagnosed with syphilis might be prescribed a 14-day course of doxycycline pills instead of a single shot of penicillin. Adherence to a two-week pill regimen is significantly lower than a single injection, potentially leading to treatment failure and continued transmission within the community, which eventually circles back to affect pregnant women.

Section VIII: Prevention Frontiers and Future Directions

Given the difficulty of treating established infections amidst social barriers and drug shortages, the public health community is exploring new frontiers in prevention.

Doxy-PEP: A Partial Solution?

Doxycycline post-exposure prophylaxis (Doxy-PEP)—taking 200mg of doxycycline within 72 hours of condomless sex—has shown high efficacy in clinical trials. Studies in San Francisco and Seattle demonstrated that Doxy-PEP reduced the incidence of syphilis by approximately 87% in men who have sex with men (MSM) and transgender women.³⁸ Based on this, the CDC recommended Doxy-PEP for these populations in June 2024.

However, the applicability of Doxy-PEP to the maternal syphilis crisis is currently limited. A major study in Kenya involving cisgender women failed to show significant protection from STIs using Doxy-PEP.⁴⁰ The reasons for this discrepancy are debated but may involve lower adherence in the study group or biological differences in how the drug concentrates in vaginal vs. rectal tissue. Consequently, Doxy-PEP is not currently recommended for cisgender women in the US. This leaves women of reproductive age without a biomedical prevention tool comparable to PrEP for HIV, highlighting a critical gap in women's health research.

Structural Interventions: Street Medicine and Syphilis Testing

To address the "missed opportunities" linked to homelessness and lack of prenatal care, innovative care models are required. "Street medicine" programs, where providers bring care directly to encampments, are essential. These programs can perform rapid syphilis testing in the field and, crucially, provide field-based treatment (if Bicillin is available), bypassing the need for a vulnerable patient to navigate a complex hospital system.⁴¹

Additionally, the expansion of "opt-out" testing in Emergency Departments (EDs) is a vital strategy. Many women with no prenatal care still interact with the healthcare system via the ED for other reasons. Implementing routine syphilis screening in EDs in high-prevalence areas can catch infections that would otherwise be missed until delivery.⁴³

Conclusion

The 28% increase in maternal syphilis rates in the United States between 2022 and 2024 is more than a statistic; it is an indictment of the nation's public health safety net. It reflects a system that has failed to protect its most vulnerable populations—Indigenous women, those living in poverty, and rural residents—from an ancient, curable, and devastating pathogen.

The crisis is a "perfect storm" of biological virulence, social determinants, and systemic fragility. Treponema pallidum is exploiting the fissures created by the methamphetamine epidemic, the housing crisis, and the erosion of rural healthcare. The collapse of the risk-based screening model and the fragility of the penicillin supply chain have further incapacitated the response.

As we look to the future, the path forward requires a multi-faceted approach. The implementation of universal triple-screening in pregnancy is a necessary first step. However, screening alone is insufficient without access to treatment. Stabilizing the Bicillin L-A supply chain is a matter of national health security. Furthermore, addressing the syndemic drivers—providing housing, addiction treatment, and culturally competent care for Indigenous communities—is essential. Until these structural root causes are addressed, the "Great Imitator" will continue to exact a heavy and preventable toll on the next generation of American children.

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