We conducted a review of the literature by searching PubMed using the terms “human papillomavirus” or “HPV”, “HIV” or “human immunodeficiency virus”, and “MSM” or “men who have sex with men” to find articles published from September, 1998 to August, 2012. Studies were included irrespective of testing methods used for HIV and HPV diagnosis. We excluded studies without HPV data from both HIV-infected and HIV-uninfected individuals. We also excluded studies that were not written in English, or opinion papers, commentaries, case reports, and subsamples from original papers. Additionally, we identified significant references in review papers and subsequently excluded the review paper itself.

Our search criteria identified 110 articles of which 20 were eliminated because they were reviews of published research (n = 9), were not research studies (n = 10), and not written in English (n = 1). Of the 90 remaining articles we eliminated 79 because they had no data on HIV (n=3), HIV prevalence was not assessed (n = 16), HPV prevalence was not assessed (n = 1), MSM were not the target population (n = 3), the effect of HIV on HPV incidence was assessed (opposite direction; n = 1), neither HPV nor HIV were assessed (n = 37) nor a correlation was made between HIV and HPV (n = 17), specimen obtained for HPV testing was not anorectal (n = 1). The remaining 11 articles met the inclusion criteria and were selected for content analysis (Figure 1). Three of the 11 studies included in this review had a cohort study design and the remaining 8 were cross-sectional studies. Furthermore, our selected articles provided both cross-sectional [4,8,10,11,13,15,16,17] and longitudinal data [3,9,18] comparing HPV and HIV. Four of the 11 studies were conducted in the US and the other 7 in Buenos Aires (n = 1), Lima Peru (n = 1), Vancouver, Canada (n = 1), China (n = 2), Germany (n = 1) and Netherlands (n = 1) (Table 1). MSM were defined as individuals who were gay, bisexual, reported same sex encounters, and engaged in either insertive or receptive anal sex. The prevalence of HIV infection in MSM across all 11 studies ranged from 1.17% [1], to 85% [5]. HIV information was collected by self-report, ELISA with Western Blot confirmation, non-specified test on dried blood spot specimens, immunofluorescence and PCR confirmation, and non-specified HIV antibody detection test. Anal HPV prevalence among MSM across all 11 studies ranged between 13.7% [14] and 98% [5]. High risk oncogenic genotypes were assessed in all 11 research studies and testing methods for HPV included PCR + restriction fragment length polymorphism, line blot assay, Tellgenplex HPV DNA test, Linear Array line blot, linear array probe, suspension bead array method, hybrid capture II, cytology, dot blot hybridization, and SPF LIPA HPV PCR. Specimens for HPV testing were derived from perianal swabs, anal swabs, punch biopsies, digital rectal examination, anorectal swabs, and rectal swabs. With respect to the role of HPV in HIV acquisition, only one [1] of the 11 selected studies assessed this relationship in HIV-uninfected MSM. Among MSM 57% were infected with HPV, 26% with high risk HPV and 26% with low risk HPV. Of 1409 participants who contributed 4375 person years of follow-up, 51 sero-converted, leading to an HIV acquisition rate of 1.17 per 100-person years. The authors reported an unadjusted hazard ratio (uHR) of 2.8 (95% Confidence Interval (CI) 1.04-7.4, p = 0.04) in the association between having one type of HPV and HIV sero-conversion. Similarly, an uHR of 3.6 (95% CI 1.5-8.4, p = 0.004) and adjusted hazard ratio (aHR) of 3.5 (95% CI 1.2-10.6, p = 0.02) were reported in the association between having 2 or more types of HPV and HIV sero-conversion. Other variables that showed a statistically significant relationship with HIV sero-conversion were unprotected receptive anal intercourse with HIV-unknown partners (adjusted HR of 7.1, 95% CI 2.8-18.2, p < 0.0001) and methamphetamine use (adjusted HR of 4.6, 95% CI 1.7-12.0, p = 0.002). The same authors also found some evidence that abnormal anal cytology (Atypical Squamous Cells of Unidentified Significance (ASCUS)) was associated with HIV sero-conversion (HR 2.9, 95% CI 1.1-7.5, p = 0.03).

We reviewed published research studies about the role of HPV in HIV-acquisition among MSM. Overall and across all relevant studies, the prevalence of HPV infection was significantly higher in MSM compared to demographically similar non-MSM. Moreover, the prevalence of HIV infection was higher in MSM compared to non-MSM and the prevalence of HPV infection was higher in HIV-infected MSM compared to HIV-uninfected MSM. These findings are consistent with a significant body of literature underscoring the vulnerability of MSM compared to the general population to disproportionately higher rates of STIs including HIV and HPV. Although the relationship between most common STIs and HIV infection is well established in the literature, few studies directly address the relationship between HPV infection and HIV incidence. In the published studies that addressed HIV incidence and HPV infection, there are limitations to the interpretation and generalizability of the findings due to potential confounders. One [1] of the 11 selected articles for review examined the direct association between HPV and HIV-acquisition in MSM. The study reported a 3.62% HIV incidence rate of 1.17 per 100-person years. The study also found that HPV was independently associated with HIV sero-conversion. Additionally, infection with one or more genotypes of HPV significantly increased the risk of acquiring HIV infection. The biological plausibility of increased HIV acquisition due to HPV infection as discussed by the authors suggest that HPV-related lesions facilitate the aggregation of HIV-susceptible cells (T-cells and macrophages) at the site of the lesion making them more accessible to HIV. The authors also noted that HPV lesions cause disruptions in the normal anorectal anatomical barrier [1].