Human papilloma virus genotype distribution and risk factor analysis amongst reproductive-age women in urban Gambia.

Abstract

Cervical cancer is the most frequently diagnosed female cancer in The Gambia, representing approximately 30 % of cases. In 2014, the quadrivalent human papilloma virus (HPV) vaccine was introduced, which offers protection against HPV genotypes 6, 11, 16 and 18. To evaluate the potential effectiveness of this vaccine, genotype distribution and risk factor analysis were assessed. Endocervical samples (n=232) were collected from women aged 20-49 years residing in urban Gambia. A questionnaire was administered to capture socio-demographic and cervical cancer risk factors. HPV detection and genotyping was performed by PCR amplification of the L1 major capsid gene and analysis of sequenced PCR products.Results/Key findings. The prevalence of HPV was 12 % (28/232), and the high-risk (HR) genotype HPV 52 (5/28) was the most prevalent genotype. HR-HPV sequences had high identity (≥90 %) to isolates which originated from America, Europe and Asia but not from Africa. Half (14/28) of participants were co-infected with Ureaplasma urealyticum/parvum, which increases the risk of progression to cervical cancer. Female genital mutilation and the use of hormone contraception for >5 years were identified as potential risk factors for HPV infection. Ethnicity-associated differences were also noted; participants of the Fula ethnic group had a higher prevalence of HR-HPV infection (31.3 %) compared to the Mandinka (18.8 %) and Wollof (12.5 %) groups. These data may have a significant public health impact as the HPV quadrivalent vaccine may be of limited value if the circulating non-HPV 16/18 HR-genotypes are responsible for cytological abnormalities of the cervix.