Objective: To identify the risk factors for gonorrhoea, syphilis, and trichomonas infections among low risk women in Nairobi, Kenya.
Method: In a cross-sectional study, 4,404 women attending two peri-urban family planning clinics between 1989 and 1991 were interviewed using a structured questionnaire and examined for signs of sexually transmitted disease (STD) infection. Cervical cultures for gonorrhoea, PAP smear (including microscopy for trichomonas), RPR and HIV testing were done.
Results: Positive cervical cultures for gonorrhoea were found in 3.2% of women, positive syphilis serology in 1.9%, and positive trichomonas microscopy in 5.2%. Genital ulcers were found in 1.9% of women. Although unmarried status and reporting more than one sex partner in the previous year were both significantly associated with each disease in the crude analysis, these associations were attenuated after controlling for each other and for other risk factors. The population attributable risks (PARs) for these factors were low (7-16%) owing to the high proportion of cases who were married and monogamous. The majority of women with microbiological evidence of infection had normal pelvic examinations. Clinical diagnostic algorithms for STDs in this population had a low sensitivity and positive predictive value. Nevertheless, a strong association between HIV seropositivity and STDs was observed.
Conclusion: The low population attributable risks found in this study suggest that behaviour change messages directed to women, particularly if they are married have a low potential for preventing STDs. The poor performance of clinical diagnostic algorithms illustrates the desirability of testing these algorithms in a variety of populations and reinforces the need for low-cost methods of microbiologic diagnosis if populations with relatively low prevalences of these infections are to be included in programmes to diagnose and treat STDs.
PIP: Between October 1989 and May 1991 in Kenya, clinicians interviewed and took cervical cultures from 4404 women attending 2 periurban family planning clinics in predominantly lower socioeconomic areas of Nairobi to determine risk factors for sexually transmitted diseases (STDs) among low-risk women. Most women were married and/or had only one sexual partner in the past year. The STD prevalence rates were 3.2% for gonorrhea, 1.9% for syphilis, 5.2% for trichomonas, and 4.9% for HIV infection. The crude analysis showed that unmarried status and at least 2 sexual partners in the last year were significantly correlated with each STD. When the researchers controlled for each disease and for other risk factors, however, neither unmarried status nor at least 2 sexual partners were associated with the STDs. The population attributable risks (PARs) for unmarried women were 9.7% for gonorrhea, 9.1% for syphilis, and 15.9% for trichomonas. The PARs for more than 1 sexual partner were 7.7%, 7.2%, and 7.4%, respectively. These PARs were relatively low due to the considerable proportion of married and monogamous women in the sample. HIV seropositivity was the most significant predictor of gonorrhea, syphilis, and trichomonas infections (odds ratio = 1.9-3.4). The pelvic examinations of most women who had microbiological evidence of an STD were normal. The clinical diagnostic algorithms for STDs in the study used the most readily accessible and significant risk factors and physical examination findings. They had a relatively high specificity (76 - 99%) but low sensitivity ( 1 - 38%). These findings showed that none of the risk factors or the physical examination could be sufficiently used to predict an STD diagnosis. They also indicate the need for inexpensive diagnostic tests to identify and treat women at a relatively low risk of STDs in family planning and other clinics.