Héctor Posso

Prevalence and determinants of HPV infection among Colombian women with normal cytology

Human papillomavirus is the principal risk factor associated with cervical cancer, the most common malignancy among women in Colombia. We conducted a survey, aiming to report type specific prevalence and determinants of human papillomavirus infection in women with normal cytology. A total of 1859 women from Bogota, Colombia were interviewed and tested for human papillomavirus using a general primer GP5+/GP6+ mediated PCR–EIA. The overall HPV DNA prevalence was 14.8%; 9% of the women were infected by high risk types, 3.1% by low risk types, 2.3% by both high risk/low risk types and 0.4% by uncharacterized types (human papillomavirus X). Thirty-two different human papillomavirus types were detected, being human papillomavirus 16, 58, 56, 81(CP8304) and 18 the most common types. The human papillomavirus prevalence was 26.1% among women younger than 20 years, 2.3% in women aged 45–54 years, and 13.2% in women aged 55 years or more. For low risk types the highest peak of prevalence was observed in women aged 55 years or more. Compared to women aged 35–44 years, women aged less than 20 years had a 10-fold increased risk of having multiple infections. Besides age, there was a positive association between the risk of human papillomavirus infection and number of regular sexual partners and oral contraceptive use. In women aged below 25 years, high educational level and having had casual sexual partners predicted infection risk. In conclusion, there was a broad diversity of human papillomavirus infections with high risk types being the most common types detected. In this population multiplicity of sexual partners and, among young women, high educational level and casual sexual partners seem to determine risk.

The Natural Course of Chlamydia trachomatis Infection in Asymptomatic Colombian Women: A 5-Year Follow-Up Study

The natural course of Chlamydia trachomatis infection and its risk factors were studied in Colombian women with normal cytological results, during a 5-year period. Eighty-two women who were found to be positive for C. trachomatis at the start of the study were studied at 6-month intervals. At each visit, a cervical scrape sample was obtained for detection of C. trachomatis by use of C. trachomatis endogenous-plasmid polymerase chain reaction (PCR)-enzyme immunoassay and VD2-PCR-reverse line blot assay. Of the women studied, 67% had a single-serovar infection, 10% had a mixed-serovar infection, and 23% had an infection with an unidentified type. An inversed rate of clearance of C. trachomatis infection was observed with oral contraceptive use (hazard ratio [HR], 1.7 [95% confidence interval {CI}, 1.1-2.7]) and first sexual intercourse at >/=20 years of age (HR, 4.3 [95% CI, 2.3-8.0]). Serovars of group B (B, D, and E) and C (H, I, J, and K) had a decreased rate of clearance (rate ratio, 0.4 [95% CI, 0.1-0.9]), compared with that for serovars of the intermediate group (F and G). At 4 years of follow-up, 94% of the women had cleared their infections.

Smoking and human papillomavirus infection: pooled analysis of the International Agency for Research on Cancer HPV Prevalence Surveys

BACKGROUND Smoking increases the risk of squamous-cell carcinoma of the cervix, but it is not clear whether smoking increases the risk of acquisition or persistence of human papillomavirus (HPV) infection. METHODS Information on smoking was collected from 10 areas in four continents among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was performed using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) of being HPV-positive by smoking habits, adjusted for age and lifetime number of sexual partners. RESULTS Ten thousand five hundred and seventy-seven women (mean age 41.4 years) were included. Among current smokers, the risk of being HPV-positive increased with smoking intensity, after allowing for lifetime number of sexual partners: ORs for <5, 5-14 and >/=15 cigarettes per day were 1.21 (95% CI 0.95-1.54), 1.39 (95% CI 1.04-1.87) and 2.01 (95% CI 1.32-3.08), respectively, as compared with never-smokers. The risk among former smokers (OR = 0.95, 95% CI 0.73-1.23) was similar to that among never-smokers. Analyses stratified by lifetime number of sexual partners showed a significant trend in risk only for women with one lifetime sexual partner. CONCLUSIONS Our study suggests that current, though not former, smoking is associated with an increased prevalence of HPV, after allowance for sexual covariates. Among current smokers, HPV prevalence increased with smoking intensity, but a clear dose-response relationship was exclusively seen among women who declared one lifetime sexual partner.

Cervical Coinfection with Human Papillomavirus (HPV) Types and Possible Implications for the Prevention of Cervical Cancer by HPV Vaccines

Coinfection with multiple types of human papillomavirus (HPV) and its implications for the development of efficacious HPV vaccines is a subject of great interest. To describe the occurrence of concurrent infection with multiple HPV types and to determine whether genital HPV infection modifies the risk of acquiring a new HPV infection with another HPV type, 1610 subjects were monitored for an average of 4.1 years in Bogota, Colombia. Information on risk factors for HPV infection and cervical cells was collected for detection of HPV DNA of 36 types at study entry and at 6 consecutive 6-month follow-up visits. Clustering or the concurrent acquisition of multiple types occurred more often than would be expected by chance. Subjects with incident HPV-16 or -18 infection had 5-7 times higher odds of acquiring a subsequent HPV-58 infection than subjects not infected with HPV-16 or -18. This might affect the protection conferred by effective HPV vaccines.

Reproductive Factors, Oral Contraceptive Use, and Human Papillomavirus Infection: Pooled Analysis of the IARC HPV Prevalence Surveys

High parity, early age at first full-term pregnancy (FTP), and long-term oral contraceptive (OC) use increase cervical cancer risk, but it is unclear whether these variables are also associated with increased risk of acquisition and persistence of human papillomavirus (HPV) infection, the main cause of cervical cancer. Information on reproductive and menstrual characteristics and OC use were collected from 14 areas worldwide, among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was done using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate the odds ratios (OR) of being HPV-positive according to reproductive and menstrual factors and corresponding 95% confidence intervals (CI). When more than two groups were compared, floating CIs (FCI) were estimated. A total of 15,145 women (mean age, 40.9 years) were analyzed. Women with ≥5 FTPs (OR, 0.90; 95% FCI, 0.76-1.06) showed a similar risk of being HPV-positive compared with women with only one FTP (OR, 1.00; 95% FCI, 0.86-1.16). However, nulliparous women showed an OR of 1.40 (95% CI, 1.16-1.69) compared with parous women. Early age at first FTP was not significantly related to HPV positivity. HPV positivity was similar for women who reported ≥10 years of use of OCs (OR, 1.16; 95% FCI, 0.85-1.58) and never users of OCs (OR, 1.00; 95% FCI, 0.90-1.12). Our study suggests, therefore, that high parity, early age at first FTP, and long-term OC use are not associated with HPV prevalence, but rather these factors might be involved in the transition from HPV infection to neoplastic cervical lesions. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2148–53)

Persistence of HPV infection and risk of high-grade cervical intraepithelial neoplasia in a cohort of Colombian women

Little is known about the dynamics of human papillomavirus (HPV) infection and subsequent development of high-grade cervical intraepithelial neoplasia (CIN2/3), particularly in women >30 years of age. This information is needed to assess the impact of HPV vaccines and consider new screening strategies. A cohort of 1728 women 15–85 years old with normal cytology at baseline was followed every 6 months for an average of 9 years. Women with squamous intraepithelial lesions were referred for biopsy and treatment. The Kaplan–Meier method was used to estimate the median duration of infection and Cox regression analysis was undertaken to assess determinants of clearance and risk of CIN2/3 associated with HPV persistence. No difference in the likelihood of clearance was observed by HPV type or womans age, with the exception of lower clearance for HPV16 infection in women under 30 years of age. Viral load was inversely associated with clearance. In conclusion, viral load is the main determinant of persistence, and persistence of HPV16 infections carry a higher risk of CIN2/3.

Cervical Infection With Chlamydia trachomatis and Neisseria gonorrhoeae in Women From Ten Areas in Four Continents A Cross-Sectional Study

Objectives: Better information on the prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection is needed in many world areas. Study Design: Cross-sectional study of population-based samples of nonpregnant women aged 15 to 44 years in Nigeria, Colombia, Argentina, Vietnam (2 areas), China, Thailand (2 areas), Korea, and Spain. 5,328 consenting women aged 15 to 44 years participated. Exfoliated cervical cells were collected and testing for CT and NG and human papillomavirus (HPV) was done using PCR-based assays. Results: Age-standardized CT prevalence ranged between 0.2% (95% confidence interval, CI: 0.0–0.7%) in Spain and 5.6% (95% CI: 3.4–7.8%) in Nigeria. NG ranged between 0% (with broad CIs) in several areas and 2.6% (95% CI: 1.0–4.2%) in Nigeria. Prevalence of CT in all areas combined was greater in women aged 15 to 24 (4.5; 95% CI: 3.4–5.8%) than 25 to 44 (2.6; 95% CI: 2.1–3.1%), whereas NG prevalence was similar in the 2 age groups (0.3%). The only significant risk factors were NG infection (for CT), CT infection (for NG) and infection with high-risk HPV types (for both). Conclusions: The prevalence of CT and, most notably, NG was relatively low in a variety of countries. Our findings, however, do not apply to subsets of high-risk women who are likely to be underrepresented in our population-based samples.

Low grade squamous intra-epithelial lesions and human papillomavirus infection in Colombian women

Low grade squamous intra-epithelial lesions could be considered as a manifestation of human papillomavirus exposition, however the discrepancy between rates of infection with human papillomavirus and development of low grade squamous intra-epithelial lesions is notable. Here we report a cross-sectional three-armed case–control study in the Colombian population, to compare the risk factors of women with low grade squamous intra-epithelial lesions with that of human papillomavirus DNA-negative and positive women with normal cytology.