Cost and clinical utility of repeated syphilis screening in the third trimester in a high-risk population

Identification of United States Counties at Elevated Risk for Congenital Syphilis Using Predictive Modeling and a Risk Scoring System, 2018

BACKGROUND

The persistence of congenital syphilis (CS) remains an important concern in the United States. We use the 2018 data to refine a previous predictive model that identifies US counties at elevated risk for CS in 2018.

METHODS

Using county-level socioeconomic and health-related data from various sources, we developed a logistic regression predictive model to identify county-level factors associated with a county having had 1 or more CS case reported to the National Notifiable Diseases Surveillance System in 2018. We developed a risk scoring algorithm, identified the optimal risk score cutpoint to identify counties at elevated risk, and calculated the live birth to CS case ratio for counties by predicted risk level to compare counties at elevated risk with counties not at elevated risk.

RESULTS

We identified several county-level factors associated with a county having 1 or more CS case in 2018 (area under the curve, 88.6%; Bayesian information criterion, 1551.1). Using a risk score cutoff of 8 or higher (sensitivity, 83.2%; specificity, 79.4%), this model captured 94.7% (n = 1,253) of CS cases born in 2018 and identified 850 (27%) counties as being at elevated risk for CS. The live birth to CS case ratio was lower in counties identified as at elevated risk (2,482) compared with counties categorized as not at elevated risk (10,621).

CONCLUSIONS

Identifying which counties are at highest risk for CS can help target prevention efforts and interventions. The relatively low live birth to CS case ratio in elevated risk counties suggests that implementing routine 28-week screening among pregnant women in these counties may be an efficient way to target CS prevention efforts.

Repeat screening for syphilis in pregnancy as an alternative screening strategy in the UK: a cost-effectiveness analysis

OBJECTIVES

To assess the cost-effectiveness of universal repeat screening for syphilis in late pregnancy, compared with the current strategy of single screening in early pregnancy with repeat screening offered only to high-risk women.

DESIGN

A decision tree model was developed to assess the incremental costs and health benefits of the two screening strategies. The base case analysis considered short-term costs during the pregnancy and the initial weeks after delivery. Deterministic and probabilistic sensitivity analyses and scenario analyses were conducted to assess the robustness of the results.

SETTING

UK antenatal screening programme.

POPULATION

Hypothetical cohort of pregnant women who access antenatal care and receive a syphilis screen in 1 year.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the cost to avoid one case of congenital syphilis (CS). Secondary outcomes were the cost to avoid one case of intrauterine fetal demise (IUFD) or neonatal death and the number of women needing to be screened/treated to avoid one case of CS, IUFD or neonatal death. The cost per quality-adjusted life year gained was assessed in scenario analyses.

RESULTS

Base case results indicated that for pregnant women in the UK (n=725 891), the repeat screening strategy would result in 5.5 fewer cases of CS (from 8.8 to 3.3), 0.1 fewer cases of neonatal death and 0.3 fewer cases of IUFD annually compared with the single screening strategy. This equates to an additional £1.8 million per case of CS prevented. When lifetime horizon was considered, the incremental cost-effectiveness ratio for the repeat screening strategy was £120 494.

CONCLUSIONS

Universal repeat screening for syphilis in pregnancy is unlikely to be cost-effective in the current UK setting where syphilis prevalence is low. Repeat screening may be cost-effective in countries with a higher syphilis incidence in pregnancy, particularly if the cost per screen is low.

Congenital syphilis: A contemporary update on an ancient disease

Congenital syphilis (CS) rates reached a 20-year high in the United States in 2018. Unlike previous years, most babies diagnosed with CS were born to mothers who received prenatal care, indicative of the need for better provider education and guideline adherence. Current rates suggest that screening for syphilis should be performed at the first prenatal care visit and twice during the third trimester. There are two diagnostic algorithms available for use in the United States (traditional and reverse) and providers must understand how to perform each algorithm. Treatment should be administered according to stage of syphilis per Centers for Disease Control recommendations with best neonatal outcomes seen when treatment is initiated >30 days before delivery. Benzathine Penicillin G remains the only recommended treatment of syphilis during pregnancy. In viable pregnancies, a pretreatment ultrasound is recommended to identify sonographic evidence of fetal infection and treatment should be initiated with continuous fetal monitoring to evaluate for the Jarisch-Herxheimer reaction which can cause preterm labor and fetal distress. After adequate syphilotherapy, a fourfold decline in maternal nontreponemal titers may not be observed by delivery and does not correlate with rates of CS.

Syphilis in Pregnancy

Importance

Since 2013, the United States has seen a rise in cases of congenital syphilis, culminating in a relative increase of 153% from 2013 to 2017 and 918 reported cases in 2017. In all, 50% to 80% of pregnant women with syphilis experience an adverse pregnancy outcome including stillbirth or spontaneous abortion.

Objective

This article aims to review the current evidence and recommendations for management of syphilis in pregnancy.

Evidence Acquisition

Original research articles, review articles, and guidelines on syphilis were reviewed.

Results

In pregnancy, routine screening for syphilis is recommended on initiation of prenatal care. In high-risk populations, repeat testing is recommended in the early third trimester and at delivery. Penicillin remains the recommended treatment in pregnancy. After treatment, nontreponemal titers should be repeated at minimum during the early third trimester and at delivery to assess for serologic response. In high-risk populations, titers should be repeated monthly.

Conclusion and Relevance

Routine screening in pregnancy is essential for identification of syphilis infection and prevention of congenital syphilis. Subsequent adequate treatment with penicillin therapy more than 30 days before delivery and at the correct dosages depending on the stage of infection should be incorporated into clinical practice.

Congenital Syphilis Misdiagnosed as Suspected Nonaccidental Trauma

Congenital syphilis (CS) is a preventable infection, yet the incidence has surged to the highest rates in 20 years. Because 50% of live-born infants with CS are asymptomatic at birth, there is an increasing likelihood that pediatric providers will encounter older infants whose diagnoses were missed at birth, emphasizing the importance of timely prenatal screening and treatment. We present one such case of an infant admitted twice at 3 and 4 months of age with long bone fractures and suspected nonaccidental trauma. On her second presentation, several additional symptoms prompted evaluation for and eventual diagnosis of CS. In this case, it is demonstrated that an isolated long bone fracture can be a first presentation of CS, with other classic findings possibly appearing later. Pediatric providers should be familiar with the varied presentations of CS in older children, including the radiographic findings that we describe. The rising rates of CS reveal deficiencies in our current strategy to prevent CS and, thus, we recommend reconsideration of universal syphilis screening in the third trimester and at delivery, with timely treatment to prevent CS during pregnancy.

Congenital Syphilis Prevention: Strategies, Evidence, and Future Directions

BACKGROUND

Congenital syphilis (CS)-the preventable transmission of Treponema pallidum from infected mother to fetus-remains a significant problem worldwide.

METHODS

From July through November 2017, 239 articles relevant to CS prevention were identified via keyword searches in PubMed and Google Scholar, ancestry searches, and expert recommendation. Articles were then assessed for (1) measurement of a specified CS or adverse pregnancy outcomes (APOs) and (2) geographic setting in high/upper middle income countries according to United Nations criteria. In total, 119 articles met inclusion criteria. These were then vetted for 1 of 3 arms of CS prevention, after which additional ancestral searches were conducted within each arm to arrive at the final collection of articles per CS prevention strategy-maternal prenatal treatment (n = 33), prenatal screening (n = 24), and public health interventions that support screening and treatment (n = 15).

RESULTS

Of the 7 studies that evaluated treatment with benzathine penicillin G (BPG) use within the context of a modern health care system, all showed BPG to be highly effective in CS prevention; 3 additional studies demonstrated BPG effectiveness in preventing APOs. Ten studies revealed early disease detection through prenatal screening significantly reduces CS and APOs when paired with BPG. There was limited literature evaluating public health interventions, such as partner notification, surveillance, and prenatal screening laws.

CONCLUSIONS

Congenital syphilis is a preventable disease, effectively avoided with appropriate prenatal screening and BPG therapy. Increasing syphilis rates among all adults, accompanied by gaps in the provision of prenatal care to women at high risk of infection, are major contributors to CS persistence.

Repeat Screening for Syphilis in the Third Trimester of Pregnancy: A Cost-Effectiveness Analysis

OBJECTIVE

To estimate the cost-effectiveness of screening all women during the first and third trimesters compared with screening just once during pregnancy.

METHODS

We used a theoretical cohort of 3.9 million women in the United States to model syphilis screening approaches in pregnancy, particularly comparing one-time screening with repeat third-trimester screening. Outcomes of syphilis infection included in the model were congenital syphilis, intrauterine fetal demise, neonatal death, and total quality-adjusted life-years (QALYs). Probabilities, utilities, and costs were obtained from the literature, and a cost-effectiveness threshold was set at $100,000 per QALY. A societal perspective was assumed.

RESULTS

Our model demonstrated that repeat screening in the third trimester for syphilis in pregnancy will result in fewer maternal and neonatal adverse outcomes and higher QALYs when compared with screening once in the first trimester. Specifically, we demonstrated that repeat screening results in 41 fewer neonates with evidence of congenital syphilis, 73 fewer cases of intrauterine fetal demise, 27 fewer neonatal and infant deaths, in addition to a cost savings of $52 million and 4,000 additional QALYs.

CONCLUSION

Using our baseline assumptions, our data support that in pregnancy, repeat screening for syphilis is superior to single screening during the first trimester and is both cost-effective and results in improvement in maternal and neonatal outcomes. When screening policies are being created for pregnant women, the cost-effectiveness of repeat screening for syphilis should be considered.

Effectiveness of Prenatal Screening and Treatment to Prevent Congenital Syphilis, Louisiana and Florida, 2013-2014

BACKGROUND

From 2012 to 2014, rates of congenital syphilis increased in Louisiana and Florida. We evaluated the effectiveness of early (first or second) and third trimester syphilis screening for the prevention of congenital syphilis in these high-morbidity states.

METHODS

Reported syphilis cases among pregnant women in Louisiana and Florida during January 1, 2013, to December 31, 2014, were reviewed for documented screening for syphilis in the first 2 trimesters and third trimester. Pregnant women with syphilis were linked to congenital syphilis records and stratified by whether the pregnancy led to a reported congenital syphilis case.

RESULTS

Seven hundred ten pregnant women with syphilis in Louisiana and Florida were linked to 155 congenital syphilis cases. Three hundred seventy (52%) pregnant women with syphilis were staged as early syphilis (n = 270) or high-titer late or unknown duration-latent syphilis (n = 100), and 109 (70% of the total) were linked to congenital syphilis cases. Screening in the first 2 trimesters identified 513 pregnant women who tested positive for syphilis, and 470 (92%) potential congenital syphilis were averted. One hundred nine pregnant women tested positive for syphilis in the third trimester, and 85 (78%) had babies without congenital syphilis. During their pregnancy, 85 (12%) women tested negative at least once, and 55 (65%) had babies with congenital syphilis. Thirty-nine women had no reported syphilis screening 30 days or longer before delivery.

CONCLUSIONS

Screening for syphilis both early and in the third trimester prevented many pregnant women with syphilis from having a baby with congenital syphilis. Preventing all congenital syphilis would likely require preventing all syphilis among women.

Syphilis during pregnancy: a preventable threat to maternal-fetal health

Syphilis remains the most common congenital infection worldwide and has tremendous consequences for the mother and her developing fetus if left untreated. Recently, there has been an increase in the number of congenital syphilis cases in the United States. Thus, recognition and appropriate treatment of reproductive-age women must be a priority. Testing should be performed at initiation of prenatal care and twice during the third trimester in high-risk patients. There are 2 diagnostic algorithms available and physicians should be aware of which algorithm is utilized by their testing laboratory. Women testing positive for syphilis should undergo a history and physical exam as well as testing for other sexually transmitted infections, including HIV. Serofast syphilis can occur in patients with previous adequate treatment but persistent low nontreponemal titers (<1:8). Syphilis can infect the fetus in all stages of the disease regardless of trimester and can sometimes be detected with ultrasound >20 weeks. The most common findings include hepatomegaly and placentomegaly, but also elevated peak systolic velocity in the middle cerebral artery (indicative of fetal anemia), ascites, and hydrops fetalis. Pregnancies with ultrasound abnormalities are at higher risk of compromise during syphilotherapy as well as fetal treatment failure. Thus, we recommend a pretreatment ultrasound in viable pregnancies when feasible. The only recommended treatment during pregnancy is benzathine penicillin G and it should be administered according to maternal stage of infection per Centers for Disease Control and Prevention guidelines. Women with a penicillin allergy should be desensitized and then treated with penicillin appropriate for their stage of syphilis. The Jarisch-Herxheimer reaction occurs in up to 44% of gravidas and can cause contractions, fetal heart rate abnormalities, and even stillbirth in the most severely affected pregnancies. We recommend all viable pregnancies receive the first dose of benzathine penicillin G in a labor and delivery department under continuous fetal monitoring for at least 24 hours. Thereafter, the remaining benzathine penicillin G doses can be given in an outpatient setting. The rate of maternal titer decline is not tied to pregnancy outcomes. Therefore, after adequate syphilotherapy, maternal titers should be checked monthly to ensure they are not increasing four-fold, as this may indicate reinfection or treatment failure.

Evaluation of the management of pregnancies and infants at risk for congenital syphilis: La Réunion, 2008 to 2014

OBJECTIVE

To evaluate the maternal-fetal management and follow-up of infants at risk for congenital syphilis.

STUDY DESIGN

Monocentric retrospective cohort study at the Félix Guyon Hospital, Saint-Denis, La Réunion between January 2008 and December 2014. Management of 38 pregnancies (35 women, 39 fetuses) with a positive syphilis serology was evaluated according to the Centers for Disease Control and Prevention (CDC) guidelines.

RESULTS

A total of 68% (n=26) of pregnancies were screened before 16 weeks of gestation, and 26% (n=10) had appropriate treatment. Adverse outcomes were noted in 45% of pregnancies. Neonatal serology was not performed in 7 live-born neonates (19%) and 33 infants were classifiable according to the four CDC scenarios. In the infants, adequate complementary evaluation and appropriate treatment were noted in 42% (n=13) and 55% (n=17) of cases, respectively. Rate of infant follow-up was 76% (n=16). No treatment failure was observed in infants.

CONCLUSION

Reinforcement of public health policies and a better sensitization, training and collaboration among perinatal caregivers are warranted given the gaps revealed in our study.