Risk factors for syphilis infection among pregnant women: results of a case-control study in Shenzhen, China.
BACKGROUND
China has been experiencing a rapidly growing syphilis epidemic since the early 1990s, with the reported incidence of congenital syphilis increasing from 0.01 cases per 100,000 live births in 1991 to 19.7 cases per 100,000 live births in 2005. Detailed studies of risk factors for syphilis in pregnant women are needed to inform new preventive interventions.


OBJECTIVE
To investigate factors associated with recent syphilis infection among pregnant women and recommend strategies for improved preventive interventions in the community.


METHODS
A case-control study was conducted among women attending antenatal clinics in Shenzhen City, South China. Cases were antenatal clinic women testing positive for early syphilis, based on laboratory results, with those testing negative being controls. All participants completed the same anonymous questionnaire covering demographics, lifestyle, sexual behaviour, and sexual partnerships.


RESULTS
129 cases and 345 controls were recruited. Syphilis was significantly associated with unmarried status, less education, multiple sex partners, travel of sex partner in the past 12 months, a history of induced abortion, and previous sexually transmitted infections. Overall, there were no differences between syphilis-positive and negative women in household registration status (hukou), living district and duration in Shenzhen, monthly income, and age at first sex.


CONCLUSIONS
Many demographic and behavioural risk factors are associated with syphilis among pregnant women. In the government congenital syphilis control programme, comprehensive preventive interventions should be provided in all clinical settings in addition to the current procedures for syphilis screening among antenatal women.
Institute of Dermatology, Shenzhen Chronic Disease Hospital, Shenzhen, China.
Hua
H
Zhou
Xiang-Sheng
XS
Chen
Fu-Chang
FC
Hong
Peng
P
Pan
Fan
F
Yang
Yu-Mao
YM
Cai
Yue-Ping
YP
Yin
Rosanna W
RW
Peeling
David
D
Mabey
D000328:Adult; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D036861:Delivery, Obstetric / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008427:Maternal Health Services / Q000706:statistics & numerical data; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors; D013587:Syphilis / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control