This study demonstrates the importance of HPV infection among sexually active Inuit women living in northern Quebec. Age and previous exposure measured by number of lifetime sexual partners were strong predictors of HR-HPV infection. These analyses have to be interpreted taking into account the limitations of our study. Although participants were not selected randomly, they represented 58% of women in the target age group living in the 4 primary study communities and we believe that our conclusions are generalizable to the female Inuit population of Nunavik. In addition, selection bias was assessed by comparing participants to the general female population of Nunavik, which showed comparable educational attainment, participation in the workforce, marital status, and smoking habits.15,16 The most striking difference was a lower frequency of Pap screening amongst study subjects than in the general population, except amongst participants aged 45 years and older, who were screened slightly more often.16 This suggests that the study population may in fact exhibit less health-seeking behavior than the general population and thus may be at higher risk for HPV infection and cofactors that influence its natural history.
The overall prevalence of HPV (28.9%) and HR-HPV (20.4%) in this Quebec Inuit population compares to other “high-risk” Canadian populations including Montreal University students and attendees of a Winnipeg inner-city clinic.17,18 Age-specific prevalence followed a U-shaped curve, with increasing overall HPV and HR-HPV prevalence in women aged 50 years and older, a pattern which has been reported elsewhere.14,19 Determinants of HR-HPV infection in this population of Quebec Inuit women are consistent with the literature which, across many studies, identifies age and markers of sexual activity as the most consistent risk factors for overall and HR-HPV infection.14,18,20–25 In general, less is known about predictors of infection with the α-3 and α-15 species, which represent low-risk HPV types. In our study, past exposure to HPV as measured by the lifetime number of sexual partners was not predictive of α-3/15 infection, in contrast with α-7 and α-9 species. This may reflect a high level of transmission and prevalence of α-3/15 species in this population or may be related to the collection of cervical rather than vulvar or vaginal specimens.26,27 Alpha-3/15 may more frequently infect vulvar or vaginal rather than cervical epithelium; therefore, self-obtained samples may be more appropriate to study determinants of α-3/15 infection.
The burden of HPV infection in this female Inuit population did not differ markedly from other “high-risk” populations studied in Canada17,18; yet, cervical cancer rates are clearly elevated amongst Inuit women. Although genetic host susceptibility factors28–32 represent a plausible explanation for these differences, this hypothesis is yet to be verified. Thus, this population may benefit most from improved case detection through Pap screening or HPV testing-augmented programs that specifically target peri- and postmenopausal women. In addition, although HPV vaccination is taking place in Quebec, screening will continue to play an important role in cervical cancer prevention amongst all age groups of this high-risk population.
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