Abstract

Introduction: The human papillomavirus (HPV) is necessary to cause a woman developing cervical cancer. The aim of the study was to estimate the prevalence of cervical HPV infection and HPV type-specific distribution among women who have not performed an adequate cytological screening for cervical cancer in the Autonomous Community of La Rioja (Spain).
Material and methods: The results of the HPV analysis have been evaluated in the samples of women with inadequate screening for cervical cancer (CC). The study includes a total of 1000 samples of cervical smears, collected in the period between November 2014 and November 2015 in the gynecological consultations of the San Pedro Hospital (HSP). Patients who attended the consultations of the "Healthy Woman" program (CCC consultations) of the Rioja Health Service, as well as those derived from Primary Care, were included as long as they fulfilled the conditions of entry into the study: to be older than 35 years and under 65 and without previous cytology for 3 or more years (inadequate screening of CC).Liquid-based cervical samples were collected and analyzed for cytology, HPV detection and genotyping. HPV genotyping was determined using CLART 2 (Genomics).
Results: 1000 samples were analyzed and 130 of them resulted positive for HPV, corresponding to a prevalence of 13% in the female population. According to their oncogenic capacity, they were subclassified into high-risk oncogenic viruses (HPV-AR), intermediate-risk viruses (HPV-IR) and low-risk oncogenic viruses (HPV-BR).Of these 130 positive samples, 102 were positive for HPV-AR, 49 for HPV-BR and 11 for HPV-IR. Regarding the study by genotypes of HPV, the most frequent type of HPV was the16 followed by 33, 6, 45, 18, 35, 39, 52, 58, 11, 53, 68, 31, 66, 56 , 83, 51, 84, 42, 61, 70, 72, 59, 44, 64, 89, 40, 62, 71, 81, 85, 82. Stratifying the sample by risk genotypes, 16, 33, 45 and 18 were the genotypes that were most frequently amplified. HPVs associated with a high risk of cell transformation were found in greater proportion than those of intermediate-low risk. The prevalence was inversely related to the age of the women in the screening. The presence of multiple HPV infections was demonstrated in two thirds of the women who carry HPV. 62.30% of the patients presented infection by multiple genotypes of HPV while the remaining 37.7% had infections by a single genotype. The average of genotypes in patients with multiple infection was 1.95 genotypes. The 95.06% of patients with multiple infection were infections with predominance of the HPV-HR genotype.
Conclusions: Our data are the first obtained in Spanish in patients with inadequate screening for cervical cancer found within the scope of implementation of a structured population screening. These results would serve as a reference for future prevalence studies and to evaluate the future impact of HPV vaccination campaigns.