Patterns of genotype distribution in multiple human papillomavirus infections.

The relationship between severe-grade cervical lesions and clusters of human papillomavirus (HPV) genotypes in a taxonomic classification was surveyed in 232 women with previous abnormal cytology. HPV co-infections were clustered according to phylogenetic criteria. Multiple infections were detected in 22.0% of the entire sample. Clade A10 (represented by HPV-6 and HPV-11) appeared more frequently in multiple infections than clade A9, which was represented by five of the most common high-risk types, including HPV-16. Although HPV-16 was the most frequent genotype, it was not more prevalent in multiple infections. Abortion and two or more sexual partners were risk-factors associated with HPV co-infections. Severe cervical dysplasia was associated with co-infections with oncogenic types from different clades, with the association being significant for the high-risk clades A7 and A9.

Human papillomavirus prevalence and predictors for cervical cancer among high-risk women from Rio de Janeiro, Brazil.

We assess the prevalence of human papillomavirus (HPV) and cofactors for cervical severe disease, as contribution for vaccine strategies at the right moment in which Brazilian health authorities have approved an anti-HPV vaccine. A case-control study was undertaken with 201 women who attended a public health service with previous abnormal cytology. The HPV status was ascertained by consensus primers My09/11 and typed by 6, 11, 16, 18, 31, 33, 35, and 58 specific primers. Patients diagnosed with high-grade squamous intraepithelial lesions (HSIL) and cervical cancer were referred as cases (n = 84). Patients with normal/inflammatory cervix or carrying benign cervical lesions were included in controls (n = 117). The overall prevalence of HPV infection was 75.6%, with 91.7% among cases. In spite of HPV 16 being the most frequent type (53.3%), 27.6% of infections were attributed to nonvaccine types. High-risk HPV were strongly associated to older women (OR = 6.7). Otherwise, age at the first intercourse (OR = 7.10), three or more parities (OR = 3.05), abortion episodes (OR = 4.80), and smoking (OR = 3.83) conferred a heavy effect in younger women. Among mediators affecting the progress from HSIL to cancer, age played the main role in easing the progression (OR = 1.09, P = 0.002) followed by education level (OR = 4.20, P = 0.066). White ethnia showed to be a protective factor (OR = 0.32, P = 0.055). Predictors from HPV exposure to malignant disease include demographic and behavioral factors. Public policies such as improvement of education and continued prevention campaigns might contribute to reduce this picture. This work also gives background, in identifying a target population, for implementing future vaccine strategies.