Pattern of sexually transmitted diseases among pregnant women in Burkina Faso, west Africa: potential for a clinical management based on simple approaches.

OBJECTIVES

(1) To determine the prevalence of sexually transmitted diseases (STDs) in pregnant women in Burkina Faso. (2) To evaluate the potential of clinical management of STDs based on screening with clinical data and urine leucocyte esterase test (LET).

METHODS

Cross sectional study among antenatal clinic attendees was conducted in 1994 in Ouagadougou and Bobo-Dioulasso, the two largest urban centres in Burkina Faso, where more than 94% of the pregnant women benefit from antenatal care at least twice during their pregnancy. Each woman selected underwent an interview, general and gynaecological examination. Genital samples were collected to confirm the presence of STD pathogens. Logistic regression analysis was done to identify models that predict (a) gonorrhoea and/or chlamydia, (b) trichomoniasis and/or bacterial vaginosis, (c) candidiasis. Sensitivity, specificity and positive and negative predictive values of these models were assessed using standard methods.

RESULTS

All 645 consecutive pregnant women were enrolled in the two sites. Among these women 32.4% presented at least one STD. The major STDs were: trichomoniasis (14%), bacterial vaginosis (13%), recent syphilis (3.6%), chlamydial infection (3.1%), genital warts (3%), gonococcal infection (1.6%) and genital ulcer (0.8%). Prevalence of vaginal candidiasis was 14%. The use of a risk marker (length of relationship with regular sexual partner < 3 years), and the positivity +3 of the urine LET provided a sensitivity of 80% and a positive predictive value of 7% for the screening of gonococcal and/or chlamydial infection. If clinical signs and positivity of the urine LET were taken into account sensitivity and positive predictive value of trichomoniasis and/or bacterial vaginosis screening were 77% and 37%, respectively. Clinical signs and positivity of the urine LET showed a low sensitivity (23%) for screening vaginal candidiasis.

CONCLUSIONS

The prevalence of STDs in pregnant women is high in urban Burkina Faso. Systematic screening combined with effective treatment should be included in antenatal care in the future. Urine LET, if associated with interview and clinical examination offers a simple, rapid and affordable tool for systematic screening of STDs in pregnant women. However, the proportion of overtreatments with proposed strategies will be high. Further studies are needed to develop and validate better algorithms with probably cheap laboratory tests.