A cross-sectional study to estimate high-risk human papillomavirus prevalence and type distribution in Italian women aged 18–26 years
1 Communicable Disease Epidemiology Unit, National Centre for Epidemiology, Surveillance and Health Promotion; Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
2 Analytical Cytology and Biomolecular Unit, Cancer Research and Prevention Institute, Via Cosimo il Vecchio 2, 50139 Florence, Italy
3 Medical Direction, Bambino Gesù Children’s Hospital, Piazza S. Onofrio 4, 00165 Rome, Italy
4 Unit of cancer epidemiology, Center for Cancer Prevention, S. Francesco da Paola 31, 10123 Turin, Italy
5 Hygiene and Public Health Unit, LHU Torino4, Via Aldisio 2, Ivrea, 10015 Turin, Italy
6 Department of Prevention, LHU Viterbo, via Enrico Fermi 15, 01100 Viterbo, Italy
7 Public Health Department, LHU Bologna, Via del Seminario 1, San Lazzaro di Savena, 40068, Bologna, Italy
8 Department of Prevention, LHU Avezzano-Sulmona-L’Aquila, Via Monte Velino 18, 67051 Avezzano, L’Aquila, Italy
9 San Liberatore Hospital, LHU Teramo, Viale Risorgimento, 64032 Atri, Teramo, Italy
10 Community Medicine Unit, LHU Pescara, Via Paolini 45, 65124 Pescara, Italy
11 Oncologic Screening Center, LHU Imola, viale Amendola 8, 40026 Imola, Bologna, Italy
12 Mother and Child Department, LHU Napoli 2 Nord, Corso Italia 129, 80010 Quarto, Napoli, Italy
13 Center for Experimental Research and Medical Science, University of Turin, Via Santena 7, 10126 Turin, Italy
14 S. Rinaldi Hospital, Via Serafino Rinaldi 63, 67057 Pescina, L’Aquila, Italy
15 Maggiore Hospital, LHU Bologna, Largo B. Nigrisoli 2, 40133 Bologna, Italy
BMC Infectious Diseases 2013, 13:74 doi:10.1186/1471-2334-13-74Published: 7 February 2013
Pre-vaccination information on HPV type-specific prevalence in target populations is essential for designing and monitoring immunization strategies for cervical cancer (CC) prevention. Data on HPV prevalence in Italy are available for women over the age of 24 years, target of the population-based CC screening programmes; while data of HPV prevalence in younger ages are very limited. The present study enrolled Italian women aged 18–26 years in order to assess the prevalence and distribution of high-risk (HR) HPV types. Risk-factors correlated with HR-HPV positivity were also described.
A sample of 2,289 women was randomly selected from the resident population lists of ten Local Health Units (LHUs) located in six Italian Regions scattered across the country; both rural and urban LHUs were involved. Women aged between 18 and 26 years and living in the selected LHUs were included in the study; pregnant women and women who did not speak Italian were excluded. A total of 1,102 women met the inclusion criteria and agreed to participate. Participants were offered pap test and Hybrid-Capture 2 (HC2) test for HR-HPV types and genotyping was performed on positive smears.
Out of 1,094 valid samples, 205 (18.7%) were HR-HPV positive. Women with 2–4 (ORadj = 4.15, 95%CI: 2.56-6.72) and ≥5 lifetime partners (ORadj = 10.63, 95%CI: 6.16-18.36) and women who have used any contraceptive in the last six months (ORadj = 1.67, 95%CI: 1.09-2.54) had a higher risk to be infected; women living with their partner had a lower risk (ORadj = 0.56, 95%CI: 0.34-0.92) to acquire infection than women living with parents/friends/alone. Among HC2 positive women, HPV16 was the most prevalent type (30.9%), followed by 31 (19.6%), 66 (12.9%), 51 (11.3%), 18 (8.8%), 56 (8.8%). Co-infections of HR-HC2 targeted types were found in 20.4% of positive samples. The HR-HPV prevalence in women with abnormal cytology (52.4%) was significantly higher than in women with normal cytology (14.6%); however 33.0% of HR-HPV infected women had an abnormal cytology.
HR-HPV prevalence in Italian women aged 18–26 years was 19%, higher than what detected for older women, by other studies using the same molecular method and laboratory network; this result supports the choice of electing girls before the sexual debut as the primary target of HPV vaccination. The HPV type distribution found in this study may represent a baseline picture; an accurate post-vaccine surveillance is necessary to early detect a possible genotype replacement. The high prevalence of viral types other than vaccine-HPV types supports the necessity to guarantee the progression of CC screening programmes in vaccinated women.