Epidemiological Profile of Human Papillomavirus in a Healthcare Center in Portugal: Implications for Public Health Policies

TL;DR

This study examines the prevalence and patterns of high-risk human papillomavirus (HPV) infections in Portugal, highlighting differences in age groups and potential impacts of vaccination.

Contribution

The study provides new insights into regional HPV infection patterns and their possible evolution due to vaccination and other factors.

Findings

The infection rate was 18.85%, with HPV type 31 being the most common.

Younger age groups (25-34) had a significantly higher infection rate compared to older groups.

Coinfections were common (34.1%) and varied by age and parity.

Abstract

Introduction

Human papillomavirus (HPV) infection, a prevalent sexually transmitted disease, affects the majority of sexually active individuals at least once in their lifetime. Cervical cancer stands as a significant contributor to mortality among women. Cervical cancer screening (CCS) and HPV vaccination are recent, with few studies about their impact on the prevalence of HPV types. The emergence of novel predominant pathogen strains can be driven by vaccine-induced pathogen strain replacement, thereby enhancing and altering selection.

Objective

The aim of the study was to characterize the high-risk (HR) HPV infection in two Portuguese primary care units (PCUs).

Materials and methods

In this observational, cross-sectional, and descriptive study, we included women aged 25-64 years and registered in two PCUs, who were screened by SiiMA Rastreios (population-based screening management application), and were HR-HPV positive, between August 2015 and May 2018. The results of cervical cancer screening (CCS) can be accessed through the SiiMA Rastreios information system. For data treatment, we used MS Excel (Microsoft Corporation, Redmond, Washington, USA), IBM SPSS Statistics for Windows, Version 20 (Released 2011; IBM Corp., Armonk, New York, USA), and non-parametric tests.

Results

In our study, we included 4,614 women aged between 25 and 64 years old. CCS was performed on 24.47%, of whom 39.95% were tested for HR-HPV. The infection rate was 18.85%, and all 14 types of infection were identified. The most common HPV type was 31, followed by 16 and 68. We found HPV other than 16/18 in 84.43%. We found coinfections in 34.1%, with no statistically significant difference by age group. In the 25-34 age group, the incidence of infection was 33.7% vs. 17.54% in the 35-54 age group and 4.55% in the 55-64 age group. HPV16 was the most common infection in the 25-34 age group. In nulliparous women, the most common was HPV31. The relationship between smoking habits and HR-HPV infection was statistically significant, but economic insufficiency was not.

Conclusion

The infection incidence in this study was slightly higher than in the 2011 national study. Statistically, the infection rate was significantly higher in the younger age groups. The most frequent type varied from the national and international study results. This may be due to regional differences in HPV infection, changes in the pattern of incidence, or the effect of vaccination. The HPV pattern may be changing, so the scientific community must keep updated to develop increasingly efficient screening and vaccination programs.