Prevalence and risk factors for Chlamydia trachomatis infection in low-income rural and suburban populations of Mexico.

ABSTRACT

BACKGROUND AND OBJECTIVES: In rural and suburban populations in developing countries, there is a lack of knowledge about the occurrence of Chlamydia trachomatis infection and the risk factors involved. Knowledge of the prevalence of infection is necessary to develop screening policies. GOALS To estimate the prevalence of C. trachomatis infection in a rural and a suburban area of Oaxaca, Mexico, and to identify behavioral and demographic risk factors, as well as clinical findings, that may be related to this disease. STUDY DESIGN: A cross-sectional survey was conducted among 559 women attending the Rural Hospital of Tlacolula, Oaxaca in 1994. Genitourinary signs and symptoms were recorded using a structured questionnaire and a speculum examination of the cervix. Endocervical specimens were obtained for the direct immunofluorescent diagnosis of chlamydial infection. RESULTS: Results for 41 women (7.3%) were positive for chlamydia. The prevalence was the same in rural and suburban women. In a multiple logistic regression analysis, chlamydial infection was correlated highly with young age (OR, 2.3; 95% CI, 1.2 to 4.6), oral contraceptives (OR, 2.2; 95% CI, 0.7 to 6.9), number of sex partners, and genitourinary signs or symptoms. The simultaneous presence of mucopurulent cervical discharge, cervix friability, inflammatory signs of the cervix, and urinary symptoms had the highest specificity (99.6%) and positive predictive value (86.7%) for chlamydial infection detection. CONCLUSION: C. trachomatis infection is a common sexually transmitted disease in rural and suburban women in Mexico. Nearly 1 of 8 women 15 to 25 years of age may be infected. A risk factor-based screening program should be implemented in rural and urban populations in Mexico. In rural settings, women with mucopurulent cervical discharge should be treated for chlamydial infection, even without a laboratory diagnosis.