Open Access Highly Accessed Research article

A population-based cross-sectional study of age-specific risk factors for high risk human papillomavirus prevalence in rural Nigeria

Megan A Clarke1*, Julia C Gage1, Kayode O Ajenifuja2, Nicolas A Wentzensen1, Akinfolarin C Adepiti2, Sholom Wacholder1, Robert D Burk3 and Mark Schiffman1

Author Affiliations

1 Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, DHHS, Bethesda, MD, USA

2 Department of Obstetrics, Gynaecology & Perinatology, Obafemi Awolowo University, Ile-Ife, Nigeria

3 Departments of Microbiology and Immunology, Pediatrics, Obstetrics, Gynecology, and Women's Health, and Epidemiology and Population Health, Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, New York, USA

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Infectious Agents and Cancer 2011, 6:12  doi:10.1186/1750-9378-6-12

Published: 29 July 2011

Abstract

Background

Cervical cancer, caused by persistent infection with carcinogenic human papillomavirus (HR-HPV), is particularly prevalent in Sub-Saharan Africa and is associated with a high mortality rate. Some studies in West Africa, including our own, have found unusually high HR-HPV across all ages with a slight peak in older women. This increased prevalence at older ages may complicate screen-and-treat programs, which are implemented in regions where HPV prevalence declines with age and typically target women between 30-49 years. A better understanding of the determinants of high HR-HPV prevalence at older ages is needed. The goal of this study is to explore risk factors for HR-HPV prevalence by age among women in our population-based study in Irun, a rural town in southwestern Nigeria.

Methods

1,420 women were administered a clinic-based questionnaire regarding sexual and reproductive behavior, marital status (including co-wives), and malaria exposure. Logistic regression compared questionnaire responses and PCR positivity for a set of 13 carcinogenic HR-HPV types. Results were stratified by age (15-29, 30-45, 46-55, and 56+ years).

Results

Birth control use and age at first pregnancy were associated with HR-HPV (p-value = 0.03 and 0.05, respectively). Early age at sexual debut and multiple sex partners were risks for HR-HPV, but did not reach significance (p-value = 0.1 and 0.07, respectively). Neither self-reported malaria nor presence of co-wives in the household was associated with HR-HPV (p-value = 0.85 and 0.24, respectively). In age sub-categories, early age at sexual debut was a significant risk factor for HR-HPV among women 35-45 years (p-value = 0.02). Early age at first pregnancy remained a significant risk factor for women aged 56+ years (p-value = 0.04). Greater than 2 sex partners and use of birth control were associated (though not significantly) with HR-HPV in women aged 30-45 (p-value = 0.08, respectively).

Conclusions

In this high-risk region with elevated HR-HPV prevalence at older ages, we confirmed previously described, behavioral determinants of HR-HPV. There was no association with self-reported malaria or co-wives, which we had hypothesized might correlate with HR-HPV at older ages.