A road map for the global elimination of congenital syphilis

Untreated maternal syphilis and adverse outcomes of pregnancy: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis of reported estimates of adverse pregnancy outcomes among untreated women with syphilis and women without syphilis.

METHODS

PubMed, EMBASE and Cochrane Libraries were searched for literature assessing adverse pregnancy outcomes among untreated women with seroreactivity for Treponema pallidum infection and non-seroreactive women. Adverse pregnancy outcomes were fetal loss or stillbirth, neonatal death, prematurity or low birth weight, clinical evidence of syphilis and infant death. Random-effects meta-analyses were used to calculate pooled estimates of adverse pregnancy outcomes and, where appropriate, heterogeneity was explored in group-specific analyses.

FINDINGS

Of the 3258 citations identified, only six, all case-control studies, were included in the analysis. Pooled estimates showed that among untreated pregnant women with syphilis, fetal loss and stillbirth were 21% more frequent, neonatal deaths were 9.3% more frequent and prematurity or low birth weight were 5.8% more frequent than among women without syphilis. Of the infants of mothers with untreated syphilis, 15% had clinical evidence of congenital syphilis. The single study that estimated infant death showed a 10% higher frequency among infants of mothers with syphilis. Substantial heterogeneity was found across studies in the estimates of all adverse outcomes for both women with syphilis (66.5% [95% confidence interval, CI: 58.0-74.1]; I(2) = 91.8%; P < 0.001) and women without syphilis (14.3% [95% CI: 11.8-17.2]; I(2) = 95.9%; P < 0.001).

CONCLUSION

Untreated maternal syphilis is associated with adverse pregnancy outcomes. These findings can inform policy decisions on resource allocation for the detection of syphilis and its timely treatment in pregnant women.

Early antenatal care: does it make a difference to outcomes of pregnancy associated with syphilis? A systematic review and meta-analysis

OBJECTIVE

Despite an increase in the proportion of women who access antenatal care, mother-to-child transmission of syphilis continues to be a consequence of undiagnosed, untreated, or inadequately treated maternal syphilis. We reviewed evidence on the optimal timing of antenatal interventions to prevent mother-to-child transmission of syphilis and its associated adverse outcomes.

DESIGN

Systematic review and meta-analysis of published literature. English-language articles were included if they (1) reported the gestational age at which the mother was screened or tested for syphilis; (2) reported on pregnancy outcome. No publication date limits were set.

RESULTS

We identified a total of 1,199 publications, of which 84 were selected for further review and five were included. All showed a lower prevalence of any adverse outcome among women who received an intervention (to include screening and treatment) in the first and second trimesters of pregnancy compared to the third trimester. The overall odds ratio for any adverse outcome was 2.24 (95% CI 1.28, 3.93). All sub-analyses by type of outcome presented important heterogeneity between studies, except for those studies reporting an infected infant (odds ratio 2.92, 95% CI 0.66, 12.87; I(2) = 48.2%, p = 0.165).

CONCLUSIONS

Our review has shown that the timing of antenatal care interventions makes a significant difference in the risk of having an adverse outcome due to syphilis. Women who sought care in the first two trimesters of their pregnancy, and received the appropriate intervention, were more likely to have a healthy infant, compared to women screened and treated in the third trimester. Encouraging ALL pregnant women to seek care in the first two trimesters of their pregnancy should be a priority for health programmes. For interventions to be effective within these health programmes, health systems and community engagement programmes need to be strengthened to enable pregnant women to seek antenatal care early.

Safety of benzathine penicillin for preventing congenital syphilis: a systematic review

OBJECTIVE

To estimate the risk of serious adverse reactions to benzathine penicillin in pregnant women for preventing congenital syphilis.

METHODS

We searched for clinical trials or cohorts that assessed the incidence of serious adverse reactions to benzathine penicillin in pregnant women and the general population (indirect evidence). MEDLINE, EMBASE, Scopus and other databases were searched up to December 2012. The GRADE approach was used to assess quality of evidence. Absolute risks of each study were calculated along with their 95% confidence intervals (95% CI). We employed the DerSimonian and Laird random effects model in the meta-analyses.

RESULTS

From 2,765 retrieved studies we included 13, representing 3,466,780 patients. The studies that included pregnant women were conducted to demonstrate the effectiveness of benzathine penicillin: no serious adverse reactions were reported among the 1,244 pregnant women included. In the general population, among 2,028,982 patients treated, 4 died from an adverse reaction. The pooled risk of death was virtually zero. Fifty-four cases of anaphylaxis were reported (pooled absolute risk = 0.002%; 95% CI: 0%-0.003% I(2) = 12%). From that estimate, penicillin treatment would be expected to result in an incidence of 0 to 3 cases of anaphylaxis per 100,000 treated. Any adverse reactions were reported in 6,377 patients among 3,465,322 treated with penicillin (pooled absolute risk = 0.169%; 95% CI: 0.073%-0.265% I(2) = 97%). The quality of evidence was very low.

CONCLUSION

Studies that assessed the risk of serious adverse events due to benzathine penicillin treatment in pregnant women were scarce, but no reports of adverse reactions were found. The incidence of severe adverse outcomes was very low in the general population. The risk of treating pregnant women with benzathine penicillin to prevent congenital syphilis appears very low and does not outweigh its benefits. Further research is needed to improve the quality of evidence.

Global estimates of syphilis in pregnancy and associated adverse outcomes: analysis of multinational antenatal surveillance data

BACKGROUND

The World Health Organization initiative to eliminate mother-to-child transmission of syphilis aims for ≥ 90% of pregnant women to be tested for syphilis and ≥ 90% to receive treatment by 2015. We calculated global and regional estimates of syphilis in pregnancy and associated adverse outcomes for 2008, as well as antenatal care (ANC) coverage for women with syphilis.

METHODS AND FINDINGS

Estimates were based upon a health service delivery model. National syphilis seropositivity data from 97 of 193 countries and ANC coverage from 147 countries were obtained from World Health Organization databases. Proportions of adverse outcomes and effectiveness of screening and treatment were from published literature. Regional estimates of ANC syphilis testing and treatment were examined through sensitivity analysis. In 2008, approximately 1.36 million (range: 1.16 to 1.56 million) pregnant women globally were estimated to have probable active syphilis; of these, 80% had attended ANC. Globally, 520,905 (best case: 425,847; worst case: 615,963) adverse outcomes were estimated to be caused by maternal syphilis, including approximately 212,327 (174,938; 249,716) stillbirths (>28 wk) or early fetal deaths (22 to 28 wk), 91,764 (76,141; 107,397) neonatal deaths, 65,267 (56,929; 73,605) preterm or low birth weight infants, and 151,547 (117,848; 185,245) infected newborns. Approximately 66% of adverse outcomes occurred in ANC attendees who were not tested or were not treated for syphilis. In 2008, based on the middle case scenario, clinical services likely averted 26% of all adverse outcomes. Limitations include missing syphilis seropositivity data for many countries in Europe, the Mediterranean, and North America, and use of estimates for the proportion of syphilis that was "probable active," and for testing and treatment coverage.

CONCLUSIONS

Syphilis continues to affect large numbers of pregnant women, causing substantial perinatal morbidity and mortality that could be prevented by early testing and treatment. In this analysis, most adverse outcomes occurred among women who attended ANC but were not tested or treated for syphilis, highlighting the need to improve the quality of ANC as well as ANC coverage. In addition, improved ANC data on syphilis testing coverage, positivity, and treatment are needed. Please see later in the article for the Editors' Summary.

Clinical and socioeconomic determinants of congenital syphilis in Posadas, Argentina

OBJECTIVES

To explore clinical and socioeconomic factors related to congenital syphilis in Posadas, Argentina.

METHODS

Data were collected from 102 mothers who had given birth to an infant with congenital syphilis at Dr. Ramón Madariaga Central Hospital (2005-2007) and 306 control mothers. Clinical and demographic information were collected from clinical records, and socioeconomic details were obtained by interview. Multivariable logistic regression was used to explore the relationships between congenital syphilis and clinical and socioeconomic factors.

RESULTS

Receiving the recommended number of prenatal health checks had a clear protective effect on congenital syphilis in the univariate analysis (odds ratio (OR) 0.52, 95% confidence interval (CI) 0.31-0.86), as did being in a stable relationship (OR 0.23, 95% CI 0.14-0.38). Furthermore, women with secondary education or above were over four-times less likely to have a child with congenital syphilis compared to women who had not completed primary school education, even after controlling for the number of prenatal health checks and other factors (adjusted OR 0.24, 95% CI 0.08-0.72). In addition, women with previous stillborn births were over three-times more likely to have a baby with congenital syphilis after controlling for education and prenatal care (adjusted OR 3.37, 95% CI 1.24-9.16).

CONCLUSIONS

There is a clear opportunity for reducing the burden of congenital syphilis by promoting syphilis screening and treatment in women with previous stillborn births. In addition, the potential impact of more general policies addressing social determinants of health, such as those improving education, must not be overlooked.

Syphilis test availability and uptake at medical facilities in southern China

OBJECTIVE

To examine syphilis testing capacity, screening coverage rates and types of syphilis tests used in medical facilities in southern China.

METHODS

Eleven of the 14 municipalities in Guangdong province participated. Data on syphilis testing capacity, screening coverage and types of syphilis tests used were collected from all types of public medical facilities offering prenatal care (n = 109). A total of 494 680 women who delivered during 2004-2008 were studied.

FINDINGS

In 2008, 54 196 pregnant women (43.1%) were not screened for syphilis. Among such women, 32 863 (60.6%) attended clinics without any syphilis testing capacity and 21 333 (39.4%) attended clinics that performed testing but were not screened. The likelihood of not having syphilis test capacity was much higher for hygiene stations (odds ratio, OR: 10; 95% confidence interval, CI: 4-25), services at the township level (OR: 33; 95% CI: 10-100) and services with ≤ 1000 deliveries per year (OR: 1.002; 95% CI: 1.001-1.003). These same service characteristics correlated with lower screening coverage rates (P < 0.01). Only one antenatal clinic had the capacity to conduct both treponemal and non-treponemal tests for diagnosing syphilis.

CONCLUSION

Syphilis screening is available in very few of the basic medical facilities offering prenatal care where most neonates in southern China are delivered. In light of this and of the increasing incidence of syphilis in the area, expanding point-of-care rapid syphilis testing is a priority.