Introduction High-risk Human Papillomavirus (HR-HPV) infection is the causal agent of anal cancer in men who have sex with men (MSM). Herein, the prevalence of HR-HPV was evaluated by molecular biology in MSM living in Bangui, the capital of the Central African Republic (CAR).

Methods Forty-two MSM attending the Centre National de Référence des Infections Sexuellement Transmissibles et de la Thérapie Antirétrovirale (CNRISTTAR) were prospectively enrolled and tested for HPV. Genomic DNA was extracted using the DNeasy Blood and Tissue kit (Qiagen, CA, USA). Human beta-globin DNA was detected by PCR. Anyplex II HPV28 (H28) HPV Genotyping Test (Seegene, Seoul, South Korea) was used for HPV genotype distribution in human beta-globin DNA positive samples.

Results Among the 42 anal specimens, 29 (69% [95% CI: 55.0%–83.0%]) were positive for HPV DNA. Multiple genotypes infections were frequent in 86.2% (25/29; 95% CI: 73.6%–98.7%) of positive anal samples and 88% of them were infected by an average of 2.5 HR-HPV (range, 1 to 8 genotypes per anal specimen). 13.8% of anal samples were infected with a single type of HPV and all of them were high-risk types. HPV 31 was found in 65% of single HPV infection. HR-HPV type 35 was the most prevalent genotype (27.5%), followed by HPV 42 and HPV 53 (24.1%), HPV 58 and 59 (20.7%) and HPV 31 and 61 (17.2%). Interestingly, HR-HPV type 16 and 18 were poorly represented in 13.8% (4/29) and 10.3% (3/29), respectively. Only one sample was simultaneously infected by HPV 16 and HPV 18. Low-risk (LR) HPV 6 and HPV 11 were observed in 2 and 3 anal samples, respectively.

Discussion HR-HPV 35, LR-HPV 42 and LR-HPV 53 were the most prevalent genotypes in anal samples. These findings suggest unusual and unique distribution of HVP genotypes in the MSM population of Bangui, and implies that the currently available 9-valent HPV vaccine would be poorly effective in this at-risk population.