Prevalence of Syphilis among Pregnant Women in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

Objective

Syphilis is one of the most imperative STIs, caused by the spirochete Treponema pallidum. During pregnancy it is associated with disastrous health outcomes in the newborn. In sub-Saharan Africa, study findings on the prevalence of syphilis among pregnant women are highly dispersed and inconsistent. The aim of the current review is to conduct a systematic review and meta-analysis of syphilis in sub-Saharan Africa among pregnant women.

Design

Systematic review and meta-analysis.

Data Sources

Databases including MEDLINE, PubMed, Cochrane Library, Google Scholar, and HINARI and reference lists of previous prevalence studies were systematically searched for relevant literature from January 1999 to November 2018. Results were presented in forest plot, tables, and figures. Random-effects model was used for the meta-analysis. For the purpose of this review, a case of syphilis was defined as positive treponemal or nontreponemal tests among pregnant women.

Data Extraction

Our search gave a total of 262 citations from all searched databases. Of these, 44 studies fulfilling the inclusion criteria and comprising 175,546 subjects were finally included.

Results

The pooled prevalence of syphilis among pregnant women in sub-Saharan Africa was 2.9% (95%CI: 2.4%-3.4%). East and Southern African regions had a higher syphilis prevalence among pregnant women (3.2%, 95% CI: 2.3%-4.2% and 3.6%, 95%CI: 2.0%-5.1%, respectively) than the sub-Saharan African pooled prevalence. The prevalence of syphilis among pregnant women in most parts of the region seemed to have decreased over the past 20 years except for the East African region. However, prevalence did not significantly differ by region and time period.

Conclusion

This review showed a high prevalence of syphilis in sub-Saharan Africa among pregnant women. The evidence suggests strengthening the screening program during pregnancy as part of the care package during antenatal care visits. Programs focusing on primary prevention of syphilis in women should also be strengthened.

Correlates of syphilis seroreactivity among pregnant women: the HIVNET 024 Trial in Malawi, Tanzania, and Zambia

OBJECTIVES

The objectives of this cross-sectional study were to determine correlates of syphilis seroprevalence among HIV-infected and -uninfected antenatal attendees in an African multisite clinical trial, and to improve strategies for maternal syphilis prevention.

RESULTS

A total of 2,270 (86%) women were HIV-infected and 366 (14%) were HIV-uninfected. One hundred seventy-five (6.6%) were syphilis-seropositive (7.3% among HIV-infected and 2.6% HIV-uninfected women). Statistically significant correlates included geographic site (odds ratio [OR] = 4.5, Blantyre; OR = 3.2, Lilongwe; OR = 9.0, Lusaka vs. Dar es Salaam referent); HIV infection (OR = 3.3); age 20 to 24 years (OR = 2.5); being divorced, widowed, or separated (OR = 2.9); genital ulcer treatment in the last year (OR = 2.9); history of stillbirth (OR = 2.8, one stillbirth; OR = 4.3, 2-5 stillbirths); and history of preterm delivery (OR = 2.7, one preterm delivery).

CONCLUSION

Many women without identified risk factors were syphilis-seropositive. Younger HIV-infected women were at highest risk. Universal integrated antenatal HIV and syphilis screening and treatment is essential in sub-Saharan African settings.

Syphilis and HIV: a dangerous combination

HIV and syphilis affect similar patient groups and co-infection is common. All patients presenting with syphilis should be offered HIV testing and all HIV-positive patients should be regularly screened for syphilis. Syphilis agent may enhance the transmission of the other, probably through increased incidence of genital ulcers. Detection and treatment of syphilis can, therefore, help to reduce HIV transmission. Syphilis may present with non-typical features in the HIV-positive patient: there is a higher rate of symptomless primary syphilis and proportionately more HIV-positive patients present with secondary disease. Secondary infection may be more aggressive and there is an increased rate of early neurological and ophthalmic involvement. Diagnosis is generally made with serology but the clinician should be aware of the potential for false-negative serology in both primary and, less commonly, in secondary syphilis. All HIV-positive patients should be treated with a penicillin-based regimen that is adequate for the treatment of neurosyphilis. Relapse of infection is more likely in the HIV-positive patient and careful follow-up is required.