[Anogenital lesions produced by Human Papillomavirus. Prevalence study in children and adolescent not vaccinated].

UNLABELLED: In Chilean children and adolescents, human papillomavirus (HPV) infection prevalence is unknown. In 2014, the HPV vaccine was incorporated into the National Immunization Program for girls, and since 2019 for boys.

OBJECTIVE: To determine the prevalence, genotypes, and characteristics of HPV infection in children and adolescents with anogenital lesions not vaccinated against HPV.

PATIENTS AND METHOD: Children and adolescents with anogenital lesions who consulted at the Luis Calvo Mackenna Children's Hospital between 2013 and 2017 were studied. The reason for consultation, age, sex, family history of HPV lesions, history of sexual abuse, and consensual sexual activity were recorded. HPV was detected by PCR and typification by reverse hybridization of the L1 gene. The samples were analyzed in the Oncogenic Virus Section of the Institute of Public Health.

RESULTS: 110 patients were studied; 44.5% were children. HPV was detected in 34 cases (30.9% [CI95% 22.4- 40.4]), 22 (44.9%) were children and 12 (19.7%) adolescents. Eleven (91.7%) adolescents had a history of sexual con tact (p < 0.005); 4 (18.2%) children disclosed sexual abuse. HPV was found in 25% of patients with genital lesions and 50% with perianal lesions (p < 0.015). The most frequent genotypes were 59, 58, 16, 18, 6, and 11. Only low-risk genotypes were detected in children and high-risk genotypes were detected in 11/12 (91.7%) of HPV (+) adolescents.

CONCLUSION: The prevalence of HPV infection was 30%. In adolescents, the infection was related to sexual contact and high-risk HPV. In children, it was associated with low-risk genotypes. Perianal lesions are more frequently associated with HPV infec tion than genital lesions in children and adolescents. The visual inspection does not allow to specify the etiology of the genital lesions, so it is necessary to perform a PCR test for HPV.