Prevalence of Chlamydia trachomatis infection in rural Samoan women aged 18-29 and assessment of associated factors: a population based study

Abstract

Background: Genital Chlamydia trachomatis infections are the most common bacterial sexually transmitted diseases in the world and place a huge burden on healthcare resources. Knowledge on the epidemiology of Chlamydia trachomatis infections and reproductive health of women in Samoa and the Pacific in general is very limited. The current knowledge is limited to a small number of antenatal surveys and routine antenatal screening. No study has attempted to assess the population prevalence of Chlamydia trachomatis infection, and associated risk factors for infection.

Objectives: Use a cross-sectional survey to describe the prevalence of Chlamydia trachomatis infection and associated factors for infection amongst a sub-population of rural Samoan women aged 18 to 29 years.

Methods: This study on Chlamydia trachomatis infection and associated factors for infection was nested within a larger population-based cross-sectional study assessing infertility associated with Chlamydia trachomatis infection in Samoan women. The larger study utilised a random cluster sample design and aimed to recruit 800 females aged 18 to 29 years. Participants completed a questionnaire and provided a blood and urine sample to be tested for current and past Chlamydia trachomatis infection. Due to time constraints, data for inclusion within this thesis was only able to be collected from rural villages.

Results: One hundred and eighty (180) women aged 18-29 living in rural villages of Samoa were recruited into the study of risk factors associated to Chlamydia trachomatis infection. The overall prevalence of Chlamydia trachomatis infection within the study population was 36.7% (95% CI: 29.6 to 43.8) with the highest prevalence observed within the 18-24 year age group (39.2%, 95% CI: 29.3 to 49.0). Factors linked to infection within multivariate analysis, although not reaching statistical significance, were being single (OR 1.80; 95% CI, 0.92 to 3.53), having greater than two or more lifetime sexual partners (OR 2.12; 95% CI, 0.64 to 7.07), having greater than two or more sexual partners in the previous 12 months (OR 1.41; 95% CI, 0.69 to 2.89), and consumption of alcohol at least once per week (OR 2.04; 95% CI, 0.81 to 5.14). Participants reporting a past pregnancy were identified as being statistically significantly less likely to have a current Chlamydia trachomatis infection (OR 0.42; 95% CI, 0.21 to 0.84).

Discussion: The prevalence of Chlamydia trachomatis infection among Samoan women aged 18 to 29 living in rural Samoa is possibly at epidemic levels considering their potential for being a low risk group. The prevalence within this study is similar to that previously reported within opportunistic antenatal studies. The prevalence of Chlamydia trachomatis infection may potentially be higher than that reported here if urban villages were included within the study population. The inclusion criteria for the study required participants to not be using contraceptives or condoms, thus its ability to report on the true population prevalence is limited. However, the high prevalence reported here and within other data sources in Samoa has highlighted the need for interventions to address the high prevalence of Chlamydia trachomatis infection in Samoa due to the long-term reproductive sequelae associated with infection.