Prevalence and risk factors of HPV infection among women from various provinces of the world

Objective We set to estimate the genotype-speciWc prevalence of human papilloma virus (HPV) and its associated risk factors responsible among women with normal and abnormal cytology by systematic literature survey. Methods Reports on HPV prevalence published between 2000 and 2011 were retrieved. To be included, studies required information on cervical cytology, plus detailed descriptions of study populations, methods used to collect cervical samples, and assays used for HPV DNA detection and typing. Final analyses included 280 studies of which 120 were included in the Wnal analysis. The OR, 95% CI and P value were calculated using SPSS 16.0. Results Overall HPV prevalence in 576,281 women was estimated to be 32.1% (95% CI 32.098, 32.102). Corresponding estimates by region showed Eastern Asia (China) with the highest prevalence of about 57.7% of the HPV infection followed by South Central Asia (Indian subcontinent). The HPV prevalence was higher in less developed countries (42.2%) than in more developed regions (22.6%). The type-speciWc HPV prevalence study showed HPV 16 (9.5%) and 18 (6.2%) to be the prevalent type irrespective of the region of study. First coitus at a younger (15) age, increased number of pregnancies, increased number of sexual partners, use of contraceptives, smoking and chewing habit and early age at marriage were recognized as the signiWcant risk factors for HPV infection. The phylogenetic analysis of HPV-16 showed the clustering of Indian sequence with the European and American sequences suggesting a similarity between HPV types. Even though the oncogenic proteins of HPV-16 detected in more developed and less developed regions clustered, the prevalence and the severity of the diseases among the less developed regions could be well explained as the exposure of the population to the possible associated risk factors concerning to the living conditions and nature of the life style adopted by the population.