The Rise of Congenital Syphilis as a Public Health Emergency

Congenital syphilis results from the perinatal transmission of Treponema pallidum to the fetus, the consequences of which include perinatal death, as well as blindness, deafness, skeletal abnormalities, and developmental delays. Once thought to be on the verge of elimination, the incidence of congenital syphilis in recent years has increased more than 1,000%, from 335 cases in 2012 to 3,761 in 2022.¹ Yet, congenital syphilis is preventable via timely testing and treatment during pregnancy. In fact, some countries have successfully eliminated congenital syphilis via integrated public health strategies.² However, in the United States, a lack of access to equitable care, particularly for underserved communities, low clinician and patient awareness, and the unresolved national shortage of benzathine penicillin G—the only medication proven to be effective for congenital syphilis—have created the perfect storm for an unabated syphilis epidemic and should be considered a public health emergency.

The Centers for Disease Control and Prevention (CDC) currently recommend screening for maternal syphilis during the first prenatal care visit or as soon as pregnancy is identified if access to prenatal care is suboptimal and the pregnant woman 1) lives in a community with a high-prevalence of syphilis, 2) is at high-risk for syphilis based on behavioral factors, or 3) was not previously tested during pregnancy (Fig. 1). However, “high prevalence” remains difficult to define. According to the 2021 CDC sexually transmitted diseases surveillance report, more than 92% of states reported at least one case of congenital syphilis³; thus, a risk-based approach to syphilis testing may no longer be applicable, and the American College of Obstetricians and Gynecologists recently recommended universal third-trimester testing.⁴

A recent study from the CDC demonstrated that 88% of the 3,761 congenital syphilis cases in 2022 were due to a lack of timely testing and treatment.¹ By law, pregnant women in all 50 states with incomes up to 138% of the federal poverty limit are eligible for Medicaid insurance. Therefore, underserved pregnant women should be able to receive prenatal care free of charge. However, many pregnant women may still fall into the “coverage gap”—an income level above 138% of the federal poverty limit but below a sufficient threshold to afford other forms of health insurance. Similarly, to qualify for Medicaid insurance an individual must be a citizen or permanent resident with more than 5 years of residence in the United States. In 2021, there were an estimated 10.5 million unauthorized immigrants living in the United States.⁵ Emergency Medicaid provides coverage for obstetric delivery in such instances but does not provide coverage for prenatal services unless a state has opted to expand the coverage of emergency Medicaid. Currently, only 18 states have expanded the coverage of emergency Medicaid to include prenatal care.⁶

In 2021, more than 14,000 (3.9%) live births occurred among women without health insurance.⁷ Further, even pregnant women with health insurance may not be able to access care. More than 4.7 million women in the United States live in counties with limited access to maternity care services.⁸ Thus, even though affordable, safe, and effective diagnostic and therapeutic tools for syphilis have been available for decades, access to those tools remains limited, particularly for those who experience socioeconomic adversity.

Historically marginalized people suffer a disproportionate risk of obstetric morbidity and mortality,⁹ likely driven in part by an increased risk of losing health insurance coverage and a higher risk of residing in areas without access to maternity care.^10,11 Similarly, the rates of primary and secondary syphilis are two to six times higher among Hispanic and Black sexually active heterosexual women, compared with White women (Fig. 1).^12,13 The rates of congenital syphilis follow a similar distribution.¹

Lack of awareness among patients, clinicians, and the public is another key barrier to universal testing for and treatment of syphilis among pregnant women. Of the 2,335 women who attended at least one prenatal care visit in 2022 and who gave birth to a child with congenital syphilis, 17.8% had no or nontimely testing performed.¹ Further, among the 1,734 pregnant women who received timely testing and who tested positive, one in five (20%) did not receive treatment.¹ Such missed opportunities are likely driven by complex, interconnected barriers that include lack of familiarity with diagnostic algorithms and treatment regimens on the part of clinicians, and barriers to returning to care for treatment of a positive result for patients. Systemic racism likely underpins many disparities in the testing for and treatment of sexually transmitted infections among minoritized communities.^14,15 Such a cascade may begin with structural factors of residential segregation, concentrated poverty, interpersonal discrimination, increased exposure to violence, and psychosocial stress driving lower social support and higher risk behaviors for acquiring sexually transmitted infections.^14,15 Structural racism also gives rise to environments that increase the risk of using illicit substances, which is associated with an increased risk for the acquisition of syphilis,¹⁶ as well as with heighted stigma limiting care seeking.¹⁷ Stigma towards mothers of newborns with congenital syphilis,^18,19 particularly those who experience stillbirth,^20,21 may further limit the number of women presenting to care.

Finally, although benzathine penicillin G is highly efficacious and cost effective, the United States is currently facing a national shortage. In June 2023, Pfizer, the only manufacturer of benzathine penicillin G in the United States, warned it would soon run out of the medication.²² On January 10, 2024 the U.S. Food and Drug Administration (FDA) approved the temporary importation of benzathine benzylpenicillin injection from France to offset that shortage²³; however, the cost per dose may be as high as $500. Consequently, numerous health centers soon may be unable to offer treatment to pregnant women diagnosed with syphilis. Lack of financial incentives for medication production and limited demand for use in other contexts will increasingly cause pregnant women diagnosed with syphilis to go untreated.

The tools for addressing this highly morbid and rapidly worsening condition are available, and have even been used to effectively eliminate the disease in settings with far fewer resources than the United States.² What is lacking is the leadership to mobilize those tools. Thus, the dramatic and continued rise in cases of congenital syphilis should be considered a failure of our public health system to protect those most vulnerable.

Under section 319 of the Public Health Service Act, the U.S. Secretary of Health has the power to declare a public health emergency when a significant outbreak exists. Similar declarations were made during the SARS-CoV-2 pandemic²⁴ and the 2022 Mpox outbreak.²⁵ There are no established criteria, however, for defining a “significant outbreak.” We argue that a 1,000% increase in the incidence of a disease that can have lasting effects on entire communities for generations constitutes a significant outbreak. Further, we argue that such a declaration could improve access to care, increase health care clinician and patient awareness, and directly combat the national shortage of benzathine penicillin G.

During a public health emergency, under section 1135 of the Social Security Act, the Secretary of Health may waive or modify Medicaid insurance requirements, thereby closing the “coverage gap” for thousands of pregnant women. Further, allocation of reserve funds could facilitate deployment of FDA-cleared rapid point-of-care diagnostic tests to augment case finding in areas that lack adequate health care services for pregnant women, including in maternity care deserts, jails, and substance use disorder treatment programs. Such point-of-care tests have demonstrated robust performance for diagnosing syphilis²⁶ but are limited in that they cannot distinguish between prior and active infection. Commercial IgM-based assays used in other countries have shown promise for diagnosing congenital syphilis,²⁷ and during a public health emergency, expedited FDA review and emergency use authorization could make such tests widely available to clinicians in the United States. Additional benefits would include the possible expedited authorization of novel diagnostic tests and testing strategies to further improve access to care, such as contact tracing and at home testing and treatment for sex partners of infected women to reduce the spread of infection.

Declaring a public health emergency would also increase awareness and provide a vehicle through which interventions to decrease stigma could operate. Additionally, that declaration would drive the formation of groups to specifically address other barriers to universal testing and treatment. Finally, a declaration that congenital syphilis constitutes a public health emergency could facilitate increased treatment options, either by way of emergency use authorization of alternative medications for pregnant women or through the Defense Production Act, which could increase the supply of injectable benzathine penicillin G.

Importantly, assurance of equitable resource allocation will be essential. During the SARS-CoV-2 public health emergency, a growing body of literature highlighted the inconsistent distribution of medical devices, supplies, and treatments.²⁸ Congenital syphilis disproportionately affects those with the fewest resources and those with the most barriers to accessing care. Therefore, clear, concise, and standardized prioritization structures must be established at the outset, to ensure those with the greatest need receive equitable care.

Some argue that there exists public health emergency “fatigue” in the wake of those declared for the coronavirus disease 2019 (COVID-19) pandemic and the 2022 Mpox outbreak. That may be true, but it does not justify neglecting thousands of pregnant women and their unborn children. We need our political leadership to permit mobilization of the necessary resources to counteract the rising rates of congenital syphilis now, before countless families and communities are further affected.

Supplemental Digital Content

• AOG_1_2_2024_06_10_TPRALLANBLITZ_24-24_SDC1.pdf; [PDF] (640 KB)