In this cross sectional study, we have documented the diverse distribution of HPV genotypes and their associations with rigorously confirmed cervical precancerous disease endpoints, and factors associated with HPV infection among HIV-infected women in India. Overall, the prevalence of any HPV genotypes was 52.5% and prevalence of any ‘carcinogenic’ HPV genotypes was 35.3% in this cohort of HIV-infected women. The global estimates of HPV prevalence among HIV-infected women have varied by region and the level of the HIV epidemic. 
Studies in HIV-infected women from countries with generalized HIV epidemics, particularly in Africa, have reported a high (45–90%) carcinogenic HPV prevalence 
while studies from concentrated or low-level HIV epidemics in Asia, including those from India 
, Latin America 
, Europe 
, and North America 
have reported lower (20–40%) carcinogenic HPV prevalence rates among HIV-infected women. The differences in HPV prevalence in different geographical locales may be attributed to differing behavioral and immunological status of the participants, as well as the differences in primers and sensitivity of the assays used for PCR.
HPV16 was the commonest genotype (carcinogenic or otherwise) in our study in this population. It has been hypothesized HPV16 has better evolutionary ability to escape the effects of immune surveillance, while non-HPV16 genotypes are often better controlled by immune response. 
Some studies, especially in those conducted in severely immunocompromised women and those not accessing ART 
have reported higher relative preponderance of non-HPV16 genotypes. This is likely reflective of the loss of immune control against non-HPV16 genotypes in the context of severe immune suppression, and thus a relative preponderance along with HPV16. 
Yet, in our study we did not observe an increase of non-HPV16 carcinogenic genotypes with worsening immune status; while HPV16 was higher in women with lower CD4 counts and those currently taking cART. In fact, other than HPV16, we did not see any differences by ART status in any carcinogenicity grouping (data not shown). However, we did not have data on duration of ART to further explore differences between immune-replete and immunocompetent women on ART.
The overall diversity of HPV genotypes (regardless of carcinogenic grouping) found in our study is a characteristic uniformly reported from HIV-infected populations worldwide. This is in contrast to the substantially less diversity noted among HIV-uninfected women. 
The etiologic significance of this diversity and multiplicity, particularly those of concurrent ‘non/unknown carcinogenic’ HPV genotypes, often detected in the context of HIV-related immunosuppression, is not well understood. 
That said, our results suggest that future broad spectrum (polyvalent) HPV vaccines may have better efficacy in preventing CIN in higher risk groups like HIV-infected women, than the currently available bivalent (HPV16/18) or quadrivalent (HPV6/11/16/18) vaccines. 
Over half of our participants with HPV infection (74/146, 50.7%) had prevalent detection of multiple (≥2) HPV genotypes. The prevalence of multiple genotypes has varied widely (between 12%–87%) in similar studies worldwide 
, and has been associated with decreased immune response leading to reactivation of latent HPV genotypes, or reflective of high-risk sexual behaviors of HIV-infected women or their partners. Both explanations appear likely in our study, given the increasing multiplicity of HPV genotypes in women with lower immune status and higher risk behavior (reflected by number of lifetime sexual partners). Since multiplicity of HPV infections confounds exact genotype-specific attribution in cervical lesions, we explored the risk of cervical high grade neoplastic lesions (CIN3 and CIN2+) at an individual genotype-specific level, by stratifying as single or multiple carcinogenic genotypes (). While often limited by the small samples size, we have provided a framework for analysis that can be replicated in larger studies (with more CIN3/ICC endpoints) to evaluate individual genotype-specific attributions and elucidate the etiologic role of multiple infections in cervical carcinogenesis. 
Relationship of prevalent carcinogenic HPV genotypes (present singly or concurrently with carcinogenic types) with risk of CIN2+ and CIN3 in HIV-infected women in Pune, India.
We found that ≥2 lifetime sexual partners are associated with presence of any HPV infection, carcinogenic HPV infection, presence of multiple carcinogenic HPV types, and non-HPV16 carcinogenic types, but not with presence of single carcinogenic types, and with HPV16. This might be explained by the fact that HPV16 (which was also the commonest carcinogenic type present singly) is highly transmittable in comparison with other carcinogenic types, thus its prevalent detection is regardless of the multiplicity of sexual partners. It was also noteworthy that other bio-behavioral factors (e.g., parity, tobacco use) which are significant HPV co-factors in cervical carcinogenesis were not significantly associated with HPV infection status. However, we lacked adequate power to study these associations with HPV among women with high-grade cervical disease status. Elucidation of the independent or combined role of such cofactors affecting risk of carcinogenic HPV and incident cervical precancer and cancer will only be studied in prospective study designs.
With the advantages of simultaneous detection of multiple genotypes, the LA-HPV assay also has certain limitations like cross-hybridization of the HPV52 probe with that of HPV33, HPV35, and HPV58 (although we only analyzed HPV52 without concurrent present of these other genotypes), lack of quantitation of HPV viral load, and chances of carry-over contamination. 
Yet, it remains the most widely used and comprehensive commercially available assay for detection of a wide range of HPV genotypes simultaneously.
India has a high case burden of HIV/AIDS (estimated 2.4 million persons, including 1 million women) as well as a high incidence of ICC (estimated 130,000 new cases and 74,000 deaths annually). 
HIV-infected women in India are now living longer due to improved access to affordable cART in recent years. In absence of effective cervical cancer prevention services, HIV-infected women are at increased risk of ICC. Our findings add to the national and global data of HPV genotypes among HIV-infected populations. This evidence could inform the projected effectiveness of prophylactic vaccination strategies, provide background data for cost effectiveness and decision analysis models, and inform the design of HPV-based genotyping assays and biomarkers as improved screening strategies. 
The high prevalence of carcinogenic HPV reinforces the importance of regular and vigilant screening for cervical cancer and anogenital tract pathologies in this population, especially among those with lower CD4+ counts. The results also emphasize the need for larger and prospective cohort studies to further elucidate the association between immunosuppression and HPV risk, and the etiologic significance of multiple HPV infections among HIV-infected women.