Chlamydial and gonococcal cervicitis in HIV-seropositive and HIV-seronegative pregnant women in Bangkok: prevalence risk factors and relation to perinatal HIV transmission.

Numerous studies have suggested that Chlamydia trachomatis and Neisseria gonorrhoeae facilitate heterosexual HIV transmission; the impact of these sexually transmitted diseases (STDs) on perinatal HIV transmission is unknown however due to the expense of routine screening for STDs during pregnancy in developing countries. As part of a multicenter perinatal HIV transmission study 222 HIV-positive and 219 HIV-negative women presenting for prenatal care at 2 hospitals in Bangkok Thailand during 1993-94 were enrolled. At mid-pregnancy endocervical swabs were obtained and tested for the presence of C. trachomatis and N. gonorrhoeae by DNA hybridization probe. There were 36 cases (16.2%) of C. trachomatis infection among HIV-positive women and 20 cases (9.1%) among HIV-negative women. There were 6 cases (2.7%) of N. gonorrhoeae among HIV-positive women and 3 cases (1.4%) among HIV-negative women. Based on an estimated antenatal HIV seroprevalence of 2% these findings imply a general antenatal prevalence of 9.2% for C. trachomatis and 1.4% for N. gonorrhoeae. Women with gonococcal infection were more likely (relative risk 5.2) to be positive for C. trachomatis as well. C. trachomatis infection among HIV-infected pregnant women was associated with age under 21 years and primigravidity. The overall perinatal HIV transmission rate was 24.2% with no significant difference according to STD infection status. However since all women diagnosed with STDs received treatment by the mid-third trimester of pregnancy it remains possible that untreated STDs facilitate perinatal HIV transmission. The high prevalence of C. trachomatis detected in this study through use of a test not readily available in Thailand emphasizes the need for inexpensive reliable methods to screen for STDs among pregnant women in developing countries.