Syphilis is a disease that has been around for a long time and that continues to challenge clinicians, including obstetricians.1 Maternal syphilis has a severe impact on pregnancy outcome, primarily as spontaneous abortion, still birth and congenital syphilis.2 Screening of asymptomatic antenatal women is recommended to prevent perinatal complications.3 In developing countries such as India, screening for syphilis during pregnancy is carried out by Veneral Disease Research Laboratory (VDRL) tests. We undertook this retrospective study to analyse trends in syphilis prevalence among antenatal women in a tertiary care hospital of north India.
Laboratory log books of antenatal syphilis testing from 1996–2005 were reviewed. A total of 40511 serum samples were obtained from pregnant women attending (during the period January 1996 to December 2005) the antenatal clinic of Nehru Hospital, which is attached to the Postgraduate Institute of Medical Education and Research, Chandigarh, north India. All samples were subjected to VDRL testing, which was carried out using standard methods, and quantitative VDRL testing was performed for positive samples.4 Thus, a positive VDRL was considered to indicate syphilis. Treponema pallidum particulate agglutination (TPPA; Fujibero, Japan) testing was done on some positive VDRL sera due to the unavailability of kits at certain times and the inability of some women to afford the cost of the test. Age for antenatal women was recorded.
Of 40511 samples obtained during the 10‐year period, 738 (1.82%) samples were VDRL reactive. Overall, syphilis prevalence among pregnant women decreased significantly (p < 0.01) from 3% in 1996 to 0.84% in 2005, with the highest decrease occurring in 1997 (from 3% to 2.48%) and in 2004 (from 1.4 to 1%) (table 11).). Chi square testing was used to study the trends over time. TPPA could be performed only on 252 of 738 VDRL‐reactive sera. Thus, almost 50% of the reactive VDRL sera were also TPPA positive. If this figure is assessed for other VDRL‐reactive sera not subjected to TPPA testing, a total of 371 TPPA‐reactive sera may be obtained, giving a VDRL and TPPA reactivity of 0.9%. The mean age of women with a positive VDRL test was 26.5 years. The majority of women were screened between 15 and 22 weeks of gestation.
The overall VDRL positivity of 1.8% in the present study is comparable to another study carried out in Nigeria in which a prevalence of 1.3% has been reported.5 However, a limited number of studies carried out in India have shown prevalence ranging from 2.5% to 3.4%.6,7 A decline in seroreactivity for syphilis has also been reported in developing countries such as Nigeria,5 in which a decline from 3.9% to 1.3% was seen in 6 years. The downward trend in the prevalence of syphilis among pregnant women in northern India could be due to greater awareness and better education of women about the features and complications of syphilis—by both doctors and nursing staff during antenatal visits. Moreover, in India the management of sexually transmitted infections is now being monitored, which could be one of the factors for the decline. The decline could also be due to the over‐the‐counter availability of antibiotics in India, which has led to their more widespread use.
Although the prevalence rate of syphilis was low in 2005, continued screening of pregnant women should be carried out as this will reduce the adverse effects of undiagnosed and untreated syphilis. Furthermore, we recommend the treatment of all women who are VDRL reactive, irrespective of TPPA status, as reagents of TPPA are not always available in developing countries (partly due to cost). Moreover, testing of both husbands and wives is of utmost importance in the diagnosis, treatment and prevention of syphilis in newborns.