Molecular Epidemiology of Human Papillomavirus Infection of the Cervix in Women in North Tongu District, Volta Region, Ghana.

Abstract

Background: Human papillomavirus (HPV) has been well established as the primary cause of cervical squamous intraepithelial lesion/cervical intraepithelial neoplasia and invasive cervical cancer. More than 100 genotypes of HPV have been identified and 40 types are sexually transmitted. Cervical cancer is the fourth most common cancer among women worldwide and about 85% of the cases occur in developing countries. In Ghana, cervical cancer ranks as the first most frequent cancer among women. Though cervical cancer is preventable, Ghana does not have an effective national cervical cancer screening programme for women to access. Prevalence and distribution of oncogenic HPV genotype varies greatly across inter and intra countries. In Ghana, few studies on the prevalence of HPV infection and pattern of risk factors have been conducted. There is also no knowledge of published data on the prevalence of HPV genotypes in general population. Therefore, this study sought to determine the prevalence and distribution of HPV genotypes in women in the North Tongu District. Method: Five hundred women aged 15 years or older attending gynaecological clinic at Battor hospital and from three selected villages in the district were interviewed and cervical samples obtained after they gave their consent. Papanicolau smear test was performed and HPV DNA extraction, detection and genotyping performed using nested multiplex PCR technique. Prevalence of HPV and associations between exposures were determined. Results: A total of 500 women with age range 15-70 years and a median age of 35 years were interviewed. The overall HPV prevalence among the women was 47.4% with 65% of these being infected with HR types only, 11.4% with LR types only and 23.6% with both HR/LR types. There was no age preference, HPV age-specific infection rate were young women (50%), middle aged women (49.6%) and old age (55%). Multiple HPV infection among the women was 51.9%. The five most common HR HPV types in either single or multiple infections were HPV-52 (13%), HPV-18 (11%), HPV-58 (8.6%), HPV-68 (7.2%) and HPV-51 (7.0%). HPV-43 (11.3) was the most common LR HPV type (58%). Cytology results were available for 453 (90.6%) women. Majority (98.9%) of the participants had normal Pap smears, with 0.4% presenting with high-grade squamous intraepithelial lesions, 0.2% ASCUS, 0.2% HPV infection and 0.2% squamous cell carcinoma. There was significant association between marital status and HPV positivity (χ2=3.9, p=0.05) and in an unconditional logistic model, singles were significantly more likely to be infected (OR=1.9, 95% CI 1.03-3.32). There was also significant association between age at first sexual intercourse and HPV positivity ((χ2=8.9, p=0.03) and in an unconditional logistic model, women aged 14-17 years were 3 times more at risk of acquiring HPV infection (OR=2.8, 95% CI 1.40-5.58). Conclusion: High HPV prevalence (47.3%) among women in North Tongu was detected. The five most frequent HR HPV types in the women were HPV-52, HPV-18, HPV-58, HPV-68 and HPV-51 in descending order. HPV-16 was detected in the only squamous cell carcinoma found. HPV-43 was the most frequent LR HPV and HPV-6/11 the least. Multiple HPV infection was seen in about 52% of the HPV positive women. Marital status and age at first sexual intercourse were significantly associated with HPV infection. It is recommended that, Ghana Health Service should implement a national cervical cancer screening and prevention programme to reduce the incidence of cervical cancer in the country. Xvi, 112p: ill