Genotype distribution of human papillomavirus in women from the state of Bahia, Brazil

Abstract

The aim of this study was to evaluate the human papillomavirus genotypes and the frequency of multiple human papillomavirus infections, as well as to assess the association between human papillomavirus genotype, cyto-histopathological abnormalities and age range. A retrospective cross-sectional study was carried out between June 2010 and October 2013 in Salvador, Bahia, Brazil. We analyzed 351 results of positive human papillomavirus genotyping performed using the PapilloCheck(r) test, designed to detect 24 human papillomavirus types. The cyto-histopathological abnormalities were classified as negative (negative cytology and histopathology), low-grade lesions (cytologic low-grade squamous intraepithelial lesion diagnosis or histopathologic cervical intraepithelial neoplasia 1 or vaginal intraepithelial neoplasia 1 diagnosis) and high-grade lesions (cytologic high-grade squamous intraepithelial lesion diagnosis or histopathologic cervical intraepithelial neoplasia 2+ or vaginal intraepithelial neoplasia 2+ diagnosis). The most frequently detected high risk human papillomavirus genotype was HPBV 16, with 18.5%, 95% confidence interval (95%CI) 14.6-23.0, followed by HPV 56 (14%; 95%CI 10.5-18.0) and HPV 39 (13.4%; 95%CI 9.5-16.8). HPV 18 (5.4%; 95%CI 3.3-8.3) was among the least frequent types. Among the low risk types, HPV 42 (15.7%; 95%CI 12.0-20.0), HPV 6 (11.4%; 95%CI 8.3-15.2) and HPV 44/55 (11.1%; 95%CI 8.0-14.9) were the most frequent, while HPV 11 (2.8%; 95%CI 1.4-5.2) was the least common. The proportion of HPV 16-positive women increased with severity of cyto-histopathological abnormalities: 13.8% (12/87) in low-grade lesion and 42.4% (14/33) in high-grade lesion. There was association between low- or high-grade cyto-histopathological lesion and the high risk genotypes, HPV16, HPV 52, HPV 73 and HPV 82, and the low risk type, HPV 43. Women under 30 years showed a significantly higher frequency of HPV 16 (22.2 versus 12.9%, p =0.01), HPV 42 (19.7 versus 10.9%, p=0.01) and HPV 45 (6.6 versus 1.4%, p=0.01), and multiple human papillomavirus infections (58.1 versus 47.4%, p=0.04). We observed variability of human papillomavirus genotype distribution in women from the state of Bahia. HPV 16 was the most frequently detected high risk human papillomavirus, as also reported for other geographic areas of Brazil and for the world in general. HPV 56 and HPV 39 were the second and the third most common genotypes, whereas HPV 18 was among the least frequent types. HPV 42, 6 and 44/55 were the most frequently detected low risk human papillomavirus, and HPV 11 was the least common.