Prevalence and incidence of genital warts and cervical Human Papillomavirus infections in Nigerian women.

BACKGROUND: Genital warts are important causes of morbidity and their prevalence and incidence can be used to evaluate the impact of HPV vaccination in a population. METHODS: We enrolled 1020 women in a prospective cohort study in Nigeria and followed them for a mean (SD) of 9 (4) months. Nurses conducted pelvic examinations and collected ectocervical samples for HPV testing. We used exact logistic regression models to identify risk factors for genital warts. RESULTS: The mean age of study participants was 38 years, 56% (535/962) were HIV-negative and 44% (427/962) were HIV-positive. Prevalence of genital warts at enrolment was 1% (4/535) among HIV-negative women, and 5% (23/427) among HIV-positive women. Of 614 women (307 HIV negative and 307 HIV positive women) for whom we could compute genital wart incidence, it was 515 (95% CI:13-2872) per 100,000 person-years in HIV-negative and 1370 (95% CI:283-4033) per 100,000 person-years in HIV-positive women. HIV was associated with higher risk of prevalent genital warts (OR:7.14, 95% CI:2.41-28.7, p < 0.001) while higher number of sex partners in the past year was associated with increased risk of incident genital warts (OR:2.86, 95% CI:1.04-6.47. p = 0.04). HPV11 was the only HPV associated with prevalent genital warts in this population (OR:8.21, 95% CI:2.47-27.3, p = 0.001). CONCLUSION: Genital warts are common in Nigeria and our results provide important parameters for monitoring the impact of future HPV vaccination programs in the country. HIV infection and number of sexual partners in past year were important risk factors for prevalent and incident genital warts respectively.

Secular trend in interobserver agreement of VIA diagnosis for cervical cancer screening in Nigeria.

OBJECTIVE: In low resource settings, visual inspection with acetic acid (VIA) by allied health workers, has been suggested as an alternative for cervical cancer screening. However, there are concerns about the objectivity and time to diagnostic concordance with specialists. We evaluated the secular trend in interobserver agreement between nurse providers and a gynecologist/colposcopist over a five-year period. METHODS: Nurses provided VIA screening with digital cervivography to 4,961 participants in five screening clinics from October 2010 to May 2014 in Nigeria in this observational study. Cervigraphs were reviewed at meetings where a gynaecologist/colposcopist made an assessment from the cervigraphs. We used weighted kappa statistics to calculate agreement in diagnosis between nurse providers and the gynecologist/colposcopist; linear regression models to examine overall trend and investigate potential clinic characteristics that may influence agreement; and time series models to characterize month to month variations. RESULTS: Mean age of participants was 37±8 years. Overall agreement was 0.89 at Site D, 0.78 and 0.73 at Sites A and C respectively, 0.50 for Site E and 0.34 for Site C. The number of trainings attended by nurse providers(ß = 0.47,95%CI:0.02-0.93, p = 0.04), high level of engagement by site gynecologists(ß = 0.11,95%CI:0.01-0.21,p = 0.04) were associated with increased agreement; while increasing distance from the coordinating site(ß = -0.47,95%CI:-0.92-0.02,p = 0.04) was associated with decreased agreement. There were no associations between number of years screening clinics were operational(ß = 0.01,95%CI: -0.01-0.03,p = 0.29), cumulative experience of nurse providers(ß = 0.04,95%CI:-0.03-0.12,p = 0.19) and agreement. There were no significant increases in weighted kappa statistics over time for all sites considered. Monthly variations were significant for only one of two sites considered in time series models (AR1 term = -0.40, 95%CI:-0.71-0.09,p = 0.01). CONCLUSION: Our results showed a lack of objectivity, persistent variation and lack of convergence of diagnostic capabilities of nurse led VIA cervical cancer screening with the diagnostic capabilities of a specialist in a cervical cancer screening program in Nigeria.

Age, HIV status, and research context determined attrition in a longitudinal cohort in Nigeria.

OBJECTIVES: We explored determinants of attrition in a longitudinal cohort study in Nigeria. STUDY DESIGN AND SETTING: We enrolled 1,020 women into a prospective study. Of these, 973 were eligible to return for follow-up. We investigated the determinants of attrition among eligible women using a sequential mixed methods design. We used logistic regression models to compare the baseline characteristics of responders and nonresponders. At the end of the parent study, we conducted four focus group discussions and eight key informant interviews with nonresponders. RESULTS: Of the 973 women included in the quantitative analysis, 26% were nonresponders. From quantitative analysis, older women were less likely to drop out than younger women (reference: women ≤30 years; OR 0.46; 95% confidence interval [CI] 0.30-0.70, P < 0.001 women 31-44 years; and OR 0.31; 95% CI 0.17-0.56, P < 0.001 women ≥45 years). HIV-positive women were also less likely to drop out of the study (OR 0.45; 95% CI 0.33-0.63, P < 0.001). From qualitative analysis, contextual factors that influenced attrition were high cost of participation, therapeutic misconceptions, inaccurate expectations, spousal disapproval, unpleasant side effects, challenges in maintaining contact with participants, and participant difficulties in locating the study clinic. CONCLUSION: Several participant-, research-, and environment-related factors influence attrition. Retention strategies that address these barriers are important to minimize attrition.