Distribution of High Risk Human Papillomavirus Types in Western Kazakhstan - Retrospective Analysis of PCR Data

Background: Virtually all cases of cervical cancer are caused by persistent infections with a restricted set of human papillomaviruses (HPV). Cancer of the cervix is the third or even the second most common cancer in women worldwide, more than 85% of the cases occurring in developing countries, such as China and India, including the Republic of Kazakhstan. The purpose was to determine the HPV type distribution to evaluate efficacy of vaccination and adjust cancer prevention strategy in Western Kazakhstan in the future. Materials and Methods: A retrospective analysis was conducted of data obtained from PCR laboratories in 4 regional centers for the time period covering 12 months, 2013-2014, using AmpliSens Real-Time PCR kits for HPV testing of 12 genotypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59). Results: A total of 1,661 persons were HPV tested within 2013-14, but a proprotion examined for 16 and 18 genotypes only (563) was not been included for statistic analysis of distribution and ratio of the most common genotypes. Males accounted for only a small number (N=90 in total). Conclusions: Total number of the HPV-positive appeared to be 26.0%, or 286 of N=1098. Types distribution was as follows: type 16 (10.7%), 39 (5.83%), 51 (5.27%), 31 (4.85%), 56 (4.58%), 18 (3.61%), 59 (2.64%), 58 (2.22%), 35 (1.94%), 33 (1.25%). Overall the HPV infection was highest in 16-29 years old (62.4%) and decreased with age. Total prevalence of the HR-HPVs amongst male population was 21.4% with top five types 16, 18, 39, 51, 31. Trends forcorrelations between Aktau site and type 33 (Cramer's V 0.2029), between Caucasian ethnicity and type 33 (Cramer's V .1716), and between European ethnicities in Uralsk and type 45 (Cramer's V .1752) were found. Of N 563 tested separately for 16 or 18 types, 13.6% were positive. As a whole, the distribution of 16/18 types had a ratio of 3.53:1. Given the vaccine-targeted type 16 is widely spread amongst this regional population, HPV immunization program of adolescent girls 10-13 years should be implemented appropriately.