Prevalence of Anal Human Papillomavirus Infection Among HIV-Infected Women From India

To the Editors: INTRODUCTION High-risk human papillomavirus (HR-HPV), the primary cause of cervical cancer, is also associated with the development of anal cancers.1 HR-HPV has been detected in 99% of cervical cancers and 80%–90% of anal cancers.2,3 HIV-infected women have at least 7 times greater risk of developing anal carcinoma or carcinoma in situ compared with their HIV-negative counterparts.4 Prevalence of anal HPV varying from 16% to 84% has been reported among women living with HIV (WLHIV).1,5–9 A high prevalence of Pap smear abnormalities and cervical HPV (33%–47%) has been documented among Indian WLHIV.10,11 With such high rates of cervical HPV infection, rates of HPV infection in the anatomically contiguous anal region may also be expected to be higher. As HIV-infected women live longer with highly active antiretroviral treatment, they will continue to be at risk of HPV-associated diseases including dysplasia and cancer of the cervix, vulva, and anus.12 An estimated 0.816 million women were living with HIV in India by end of 2012.13 However, despite the considerable data on cervical neoplasia and HPV infection in HIV-infected women in India, there are limited data on anal neoplasia and HPV infection. Increased incidence of anorectal malignancies reported recently,14 prompted this study to assess prevalence of and factors associated with anal HPV infection among Indian WLHIV. METHODS This exploratory cross-sectional study was conducted between December 2012 and October 2013 with a planned sample size of 100. HIV-infected women older than 18 years, attending the HIV care and research clinics run by National AIDS Research Institute (NARI), Pune, India, were assessed for eligibility. Women were recruited regardless of CD4+ counts and antiretroviral therapy (ART) status. Women who were pregnant, had conditions that could preclude pelvic and/or anal examination, had a hysterectomy or history of screening/treatment for anal neoplasia, and history of HPV vaccination were excluded. Detailed demographic, sexual, and medical history, including genital cleansing practices, sexually transmitted diseases, cigarette smoking, drug, and alcohol use, were collected using a standardized questionnaire. Participants underwent general and genital examination by trained clinicians. Samples were collected for cervical and anal HPV detection and Pap smear examination using standard methods.11 Additionally, women received a symptom-directed physical examination followed by care and treatment as indicated. Women not on ART and qualifying for ART as per national guidelines were referred to the Government ART center. HPV detection was done using the PCR-based amplification of target DNA using the Linear Array HPV genotyping assay (Roche Molecular Systems Pleasanton, CA). The pool of L1 consensus PGMY09/11 primers used in this assay are designed to amplify HPV-DNA from 37 genotypes. The genotypes were classified as “carcinogenic”/high risk (HR), “possibly carcinogenic,” and “noncarcinogenic/unknown carcinogenicity” as per WHO/IARC.11 Data were analyzed using SPSS (15.0) software. Logistic regression was used for risk factor associations using demographic, sexual, and clinical data. RESULTS Of 178 women attending the NARI clinics during the study period, 124 were found eligible and offered informed consent. Of these, 24 (19.3%) women refused participation. Twelve women had “no time for participation,” one “felt unwell,” and 11 were “afraid of” or “unwilling for” anal sample collection. The median age of the women was 35 years (Q1, Q3: 30, 38), and 80% were literate with a median 9 (Q1, Q3: 7, 10) years of education. They were primarily monogamous (86%), and only 2 women had more than 3 partners in their lifetime. Sixty-nine percent of the women were currently working, with a median monthly income of Indian rupees 3550 (Q1, Q3: 2000, 5000). CD4 cell counts were available for 86 women. Median CD4 cell count among 23 women who were ART naive was 420 cells per cubic millimeter (Q1, Q3: 364, 623) and 63 women on ART was 488 cells per cubic millimeter (Q1, Q3: 365, 617) (P = 0.62). In all, 65% were on ART, for a median 2 years (Q1, Q3: 1, 4). Prevalence of anal HPV infection (any genotype) was 14/98 (14.3%), whereas multiple (≥2) HPV genotypes were present in 50% women. DNA could not be extracted in 2 samples. Carcinogenic genotypes were present in 9.2% women and possibly carcinogenic in 1%, whereas non/unknown carcinogenic types were detected in 4.1% women. Of the 37 HPV genotypes, identifiable by the Linear Array assay, 22 were detected in our participants. The HR-HPV types in declining order of prevalence included HPV-16, HPV-52, HPV-58, HPV-18, HPV-31, HPV-33, HPV-39, HPV-51, HPV-56, and HPV-59 in the anal region. Prevalence of cervical HPV infection (any genotype) was 21.2%, whereas multiple (≥2) HPV genotypes were present in 33.3% women. HR-HPV genotypes were present in 17.2% women and possibly carcinogenic in 2%, whereas non/unknown carcinogenic types were detected in 2% women. The cervical HR-HPV in declining order of prevalence included HPV-16, HPV-33, HPV-45, HPV-52, HPV-56, HPV-58, HPV-18, HPV-31, HPV-39, HPV-51, and HPV-59. Sixty-four percent of all HPV detected from the anal region, and 81% from the cervix were HR-HPV genotypes. Five women had concurrent anal and cervical infection of which 4 belonged to HR-HPV genotype. Table 1 shows the various characteristics that were studied for association with anal HPV prevalence. Although all covariates were not significant in the univariate logistic regression model, we introduced them in multivariate logistic regression because we thought them important in the context of the study. Anal sex was the only factor associated with anal HPV (adjusted odds ratio: 15.1; 95% confidence interval: 1.3 to 174.4; P = 0.03). We explored the behavioral characteristics of women who reported anal intercourse. Overall 5% of the women reported ever having had anal intercourse; none of them were currently married, whereas all except one of them were monogamous.TABLE 1: Characteristics of HIV-Infected Women and Their Association With HPV StatusDISCUSSION In this first report of anal HPV infection among WLHIV from India, we identified 14.3% overall anal HPV prevalence and 9.2% HR-HPV prevalence, which is not insignificant. The fact that this prevalence is higher than the reported 7.9% prevalence of cervical HPV among Indian women in general population with normal cytology,15 contextualizes the significance of anal HPV infection among WLHIV in our study. However, the anal HPV prevalence noted in our study was much lower than that reported from other countries.1,5–9 HPV-16, the commonest genotype reported in association with anal cancer, was also the commonest genotype detected in our study.2,11 The prevalence of concomitant cervical and anal HPV infections in our study was a little over 5% and could suggest the potential utility of screening HIV-infected women with cervical HPV or cervical cytological abnormalities for anal HPV infection. This would especially be important in light of the fact that cervical cancer diagnosis increases the risk of anorectal cancer in women.16 Receptive anal intercourse reported in our study was 5%, which again is lower than rates ranging from 6% to 33% reported in the western literature,1,5–7,17 in part explaining the cause for lower rates of anal HPV infection in our population. The sparse Indian data on heterosexual anal sex are available primarily from female sex workers with rates ranging from 11.9% in a multicentric study across 4 Indian states18 to 27% in Andhra Pradesh and Karnataka.19 In concordance with western reports, our study finds an association of HPV infection with receptive anal intercourse. In the context of India's heterosexual HIV epidemic, receptive anal intercourse among women is a relatively ignored area of research and intervention, although this can carry risks for both HIV and HPV infection.18 Higher reported rates of receptive anal intercourse among female sex workers could portend higher rates of anal HPV prevalence in this population.18,19 Based on previous evidence from Pune, and the fact that currently married women did not report it, there is a likelihood of underreporting on anal sex in our population, although care was taken to provide adequate privacy for interviews and to train the counselors who administered the questionnaire. It is possible that other methods of data collection like audio computer-assisted self-interview (ACASI) (used in the US National Survey of Family Growth)17 or polling booth method that confer more privacy to women might have yielded better reporting. We postulate that the prevailing traditions of using water for anogenital hygiene may have a protective effect against autoinoculation, although local mucosal immune mechanisms could equally play a role. Our study thus raises possibilities for research focused toward understanding the mechanisms surrounding autoinoculation. Ours was a small exploratory study conducted in HIV care clinic–based settings in one Indian city and may not be easily generalizable to the whole country. However, it remains the only evidence from India for designing larger multicentric studies. In conclusion, we provide preliminary evidence of anal HPV infection among HIV-infected women in India with prevalence that is difficult to ignore. Counseling for PLHIV in ART access clinics is typically focused on drug adherence. Including an additional behavioral component of sexual history taking and appropriate referrals during routine ART visits may help in targeting screening interventions for women. As HIV-infected women live longer due to improved ART access, considerations of public health programs for anogenital HPV testing and anal cytological screening among WLHIV in India could be approached in a multicenter operations research mode combining screening with more evidence generation.