High-risk HPV infection after five years in a population-based cohort of Chilean women

Background

The need to review cervical cancer prevention strategies has been triggered by the availability of new prevention tools linked to human papillomavirus (HPV): vaccines and screening tests. To consider these innovations, information on HPV type distribution and natural history is necessary. This is a five-year follow-up study of gynecological high-risk (HR) HPV infection among a Chilean population-based cohort of women.

Findings

A population-based random sample of 969 women from Santiago, Chile aged 17 years or older was enrolled in 2001 and revisited in 2006. At both visits they answered a survey on demographics and sexual history and provided a cervical sample for HPV DNA detection (GP5+/6+ primer-mediated PCR and Reverse line blot genotyping). Follow-up was completed by 576 (59.4%) women; 45 (4.6%) refused participation; most losses to follow-up were women who were unreachable, no longer eligible or had missing samples. HR-HPV prevalence increased by 43%. Incidence was highest in women < 20 years of age (19.4%) and lowest in women > 70 (0%); it was three times higher among women HR-HPV positive versus HPV negative at baseline (25.5% and 8.3%; OR 3.8, 95% CI 1.8-8.0). Type-specific persistence was 35.3%; it increased with age, from 0% in women < 30 years of age to 100% in women > 70. An enrollment Pap result ASCUS or worse was the only risk factor for being HR-HPV positive at both visits.

Conclusions

HR-HPV prevalence increased in the study population. All HR-HPV infections in women < 30 years old cleared, supporting the current recommendation of HR-HPV screening for women > 30 years.

[Risk factors associated with abnormal cervical cytology among Chilean women: a case control study]

BACKGROUND

Cervical cancer is the third cause of cancer death among Chilean women, affecting mainly women from low socioeconomic status.

AIM

To determine main risk factors (RF) including human papiloma virus (HPV) types associated with abnormal cervical cytology (Atypical Squamous Cells of Undetermined Significance or ASCUS) among Chilean women from low socioeconomic status in Santiago, Chile.

MATERIAL AND METHODS

A random population based sample of 616 women from La Pintana (a low-income district in Santiago) participated in 2001 in a HPV prevalence study and were re-evaluated in 2006 through a risk factors questionnaire, Papanicolaou test and DNA detection for HPV. The Papanicolaou test was analyzed in Santiago and HPV analysis (PCR_GP5+/GP6+) was conducted in Vrije University, Amsterdam. Cases included 42 women with cervical lesions and controls included 574 women with normal cytology during the period 2001-2006. Logistic regression with uni and multivariate analysis was performed to identify RF for cervical lesions.

RESULTS

During the study period, there was a significant increase in the proportion of single women, from 8.3 to 14.8% (p < 0.05), of women with 3 or more sexual partners from 8.9 to 13.3 and of women high risk HPV, from 9.1 to 14.3%. The proportion of abnormal Papanicolaou tests remained stable (3.08 and 3.9% > ASCUS). High risk HPV was the most significant factor associated with cervical lesions (odds ratio (OR) = 9.695% > confidence intervals (CI) = 4.4-21.1) followed by oral contraceptive use (OR = 2.58 95% > CI = 1.2-5.7). Among women infected by high risk HPV, the use of oral contraceptives was a risk factor while compliance with screening was protective for cervical lesions.

CONCLUSIONS

From 2001 to 2006, there was an increase in the proportion of women with high-risk HPV infections.

[Predictive factors for smoking initiation and quitting among a cohort of Chilean women followed for 5.5 years]

BACKGROUND

Chilean women have one of the highest smoking prevalence in the world.

AIM

To estimate the main factors associated with smoking initiation and quitting among a cohort of adult women living in a low socioeconomic status area of Santiago, Chile.

MATERIAL AND METHODS

A random population-based sample of 1,100 women, 18 years and older, were selected from a community located in the South East area of Santiago. Sociodemographic, as well as smoking, beliefs, behaviors, stages of change and nicotine addiction level were recorded during a personal interview. After an average follow-up period of 5.5 years, women were re-evaluated.

RESULTS

Seventy-three percent of women completed the study. At baseline, 39% of women were smokers. At the end of the study, there was an absolute smoking rate reduction of 7.1% (p<0.001). The main variables associated with smoking initiation were younger age (Odds ratio (OR): 1.08, 95% confidence intervals (CI): 1.05–1.12), higher education level (OR: 1.2, 95% CI: 1.07–1.35), and having fewer children (OR: 1.3 95% CI: 1.01–1.66). Factors related with quitting were younger age of onset (OR: 1.06 95% CI: 1.02–1.1), higher level of nicotine dependence (OR: 4.22, 95% CI: 1.74–10.27), and higher perception of smoking addiction (OR: 4.34, 95% CI: 2–9.09). Stage of change was associated with smoking cessation but its effect was diluted after adjusting for the level of nicotine addiction.

CONCLUSIONS

Sociodemographic and family factors were the main variables related with initiation, whereas age of onset, belief of addiction, and nicotine dependence were the main factors related with cessation. Women with a high motivation for quitting should be evaluated for nicotine addiction level to define the best strategy for intervention (Rev Méd Chile 2009; 137: 1001–9).