Over reporting of congenital syphilis in Guangzhou, China

New screening approach to detecting congenital syphilis in China: a retrospective cohort study

BACKGROUND

Diagnosis of congenital syphilis (CS) is not straightforward and can be challenging. This study aimed to evaluate the validity of an algorithm using timing of maternal antisyphilis treatment and titres of non-treponemal antibody as predictors of CS.

METHODS

Confirmed CS cases and those where CS was excluded were obtained from the Guangzhou Prevention of Mother-to-Child Transmission of syphilis programme between 2011 and 2019. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) using receiver operating characteristics (ROC) in two situations: (1) receiving antisyphilis treatment or no-treatment during pregnancy and (2) initiating treatment before 28 gestational weeks (GWs), initiating after 28 GWs or receiving no treatment for syphilis seropositive women.

RESULTS

Among 1558 syphilis-exposed children, 39 had confirmed CS. Area under the curve, sensitivity and specificity of maternal non-treponemal titres before treatment and treatment during pregnancy were 0.80, 76.9%, 78.7% and 0.79, 69.2%, 88.7%, respectively, for children with CS. For the algorithm, ROC results showed that PPV and NPV for predicting CS were 37.3% and 96.4% (non-treponemal titres cut-off value 1:8 and no antisyphilis treatment), 9.4% and 100% (non-treponemal titres cut-off value 1:16 and treatment after 28 GWs), 4.2% and 99.5% (non-treponemal titres cut-off value 1:32 and treatment before 28 GWs), respectively.

CONCLUSIONS

An algorithm using maternal non-treponemal titres and timing of treatment during pregnancy could be an effective strategy to diagnose or rule out CS, especially when the rate of loss to follow-up is high or there are no straightforward diagnostic tools.

Syphilis-attributable adverse pregnancy outcomes in China: a retrospective cohort analysis of 1187 pregnant women with different syphilis treatment

Background

Syphilis is responsible for a substantial burden of preventable adverse outcomes in pregnancy. The purpose of this study was to compare the frequency of adverse pregnancy outcomes among syphilis-seropositive women who received different treatment regimens at different times in Guangzhou, China.

Methods

Pregnant women with syphilis infection who received prenatal and delivery services in Guangzhou between January 2014 and December 2016 were included. Association between treatment status and the composite adverse outcomes (preterm birth, infant smaller than gestational age, stillbirth, and spontaneous abortion) was estimated.

Results

Of 1187 syphilis-seropositive pregnant women included in the analysis, 900 (75.8%) syphilis-seropositive pregnant women received treatment, and 287(24.2%) did not receive treatment. Adverse pregnancy outcomes were observed among 16.3% (147/900) of women with treatment and 33.8% (97/287) of women without treatment. Syphilis-seropositive pregnant women treated with one or two courses of penicillin had a similar risk of adverse pregnancy outcomes (adjusted RR = 1.36, 95% CI: 0.94–1.96). Adverse outcomes were more common among women whose non-treponemal serum test titer was >1:8 and received treatment after 28 weeks compared to before 28 weeks (adjusted RR = 2.34, 95% CI: 1.22–4.48).

Conclusions

Women who received one course of penicillin and women who received two courses of penicillin had a similar risk of adverse pregnancy outcomes. Syphilis treatment before 28 weeks of pregnancy is critical. Strategies to promote high-quality prenatal services are needed.

Syphilis: a fresh look at an old foe

Syphilis remains a pressing public health problem globally across different populations including men who have sex with men and pregnant women. It is timely to review what international surveillance data tell us and the evidence behind public health interventions aimed at controlling syphilis. A reinvigorated response to the re-emergence of syphilis is required.