Cervical cancer prevention by vaccination: review.

Abstract: Routine use of human papillomavirus (HPV) vaccines is recommended in adolescents under 15 years of age worldwide. Still, effective programs remain suboptimal for several factors, making the WHO strategy to eradicate cervical cancer public health with an uncertain future. Objective: To review the literature on the effectiveness, long-term protection, and safety of HPV vaccination programs and vaccination as adjuvant management. This review aims to describe the current state of vaccination programs and demonstrate the long-term protection and safety of vaccines implemented worldwide targeting adolescent girls, with the most recent published evidence of the three prophylactic HPV vaccines - bivalent (bHPV), quadrivalent (qHPV), and nonavalent (nHPV)-. We mainly focus on publications evaluating efficacy, dosing schemes, and HPV vaccination, as well as studies contributing to the mounting evidence for the real-life effectiveness of prophylactic HPV vaccines from several countries. Findings: Human Papillomavirus vaccination programs have made remarkable strides in preventing HPV-related diseases; countries with robust vaccination efforts have witnessed substantial reductions in HPV-related diseases with a decline in high-grade cervical abnormalities and genital warts (54%-83%). However, global coverage remains uneven, with disparities between high-income (HICs) and low-income countries (LMICs). The long-term efficacy of the available human papillomavirus (HPV) goes up to 9.4 years and continues to be immunogenic and well tolerated with an excellent safety profile. Conclusions and relevance: As these are crucial topics in HPV vaccination, it is essential to establish systems for continued monitoring of vaccine immunogenicity, efficacy, and safety over time.

Espacios cardioprotegidos en México: acciones para prevenir la muerte súbita cardiaca. Una postura de profesionales de la salud.

La muerte súbita cardiaca es un problema de salud pública a nivel mundial. Aunque su incidencia no es conocida, se estima que causa hasta 50% de la mortalidad de origen cardíaco y hasta 20% de la mortalidad total en los adultos. En México, estimaciones previas sugieren que causa en promedio 33 000 muertes al año; sin embargo, los datos no son precisos. La  mitad de los eventos por muerte súbita cardiaca se deben a un paro cardiaco súbito extrahospitalario que, de no ser atendido oportunamente, deriva en una muerte súbita cardiaca. Por tanto, la capacidad de responder pronta y adecuadamente a estos eventos con las maniobras y equipos necesarios mejora la sobrevida de las víctimas. Para atender este problema, en algunos estados del país se han creado espacios cardioprotegidos que permiten realizar maniobras de reanimación cardiopulmonar y desfibrilación cardiaca de acceso público oportunamente. Como objetivo, los profesionales de la salud establecen la importancia de implementar espacios cardioprotegidos y crear políticas públicas al respecto en todo el país.

Cervical cancer prevention program in Mexico disrupted due to COVID-19 pandemic: Challenges and opportunities.

Introduction: The COVID-19 pandemic disrupted the preventive services for cervical cancer (CC) control programs in Mexico, which will result in increased mortality. This study aims to assess the impact of the pandemic on the interruption of three preventive actions in the CC prevention program in Mexico. Methods: This study is a retrospective time series analysis based on administrative records for the uninsured population served by the Mexican Ministry of Health. Patient data were retrieved from the outpatient service information system and the hospital discharge database for the period 2017-2021. Data were aggregated by month, distinguishing a pre-pandemic and a pandemic period, considering April 2020 as the start date of the pandemic. A Poisson time series analysis was used to model seasonal and secular trends. Five process indicators were selected to assess the disruption of the CC program, these were analyzed as monthly data (N=39 pre-pandemic, N=21 during the pandemic). HPV vaccination indicators (number of doses and coverage) and diagnostic characteristics of CC cases were analyzed descriptively. The time elapsed between diagnosis and treatment initiation in CC cases was modeled using restricted cubic splines from robust regression. Results: Annual HPV vaccination coverage declined dramatically after 2019 and was almost null in 2021. The number of positive Papanicolaou smears decreased by 67.8% (90%CI: -72.3, -61.7) in April-December 2020, compared to their expected values without the pandemic. The immediate pandemic shock (April 2020) in the number of first-time and recurrent colposcopies was -80.5% (95%CI:-83.5, -77.0) and -77.9% (95%CI: -81.0, -74.4), respectively. An increasing trend was observed in the proportion of advanced stage and metastatic CC cases. The fraction of CC cases that did not receive medical treatment or surgery increased, as well as CC cases that received late treatment after diagnosis. Conclusions: Our analyses show significant impact of the COVID-19 pandemic with declines at all levels of CC prevention and increasing inequalities. The restarting of the preventive programs against CC in Mexico offers an opportunity to put in place actions to reduce the disparities in the burden of disease between socioeconomic levels.

Differential Antibody Response against Conformational and Linear Epitopes of the L1 Proteins from Human Papillomavirus Types 16/18 Is Observed in Vaccinated Women or with Uterine Cervical Lesions.

Antibodies against the Human Papillomavirus (HPV) L1 protein are associated with past infections and related to the evolution of the disease, whereas antibodies against L1 Virus-Like Particles (VLPs) are used to follow the neutralizing antibody response in vaccinated women. In this study, serum antibodies against conformational (VLPs) and linear epitopes of HPV16/18 L1 protein were assessed to distinguish HPV-vaccinated women from those naturally infected or those with uterine cervical lesions. The VLPs-16/18 were generated in baculovirus, and L1 proteins were obtained from denatured VLPs. Serum antibodies against VLPs and L1 proteins were evaluated by ELISA. The ELISA-VLPs and ELISA-L1 16/18 assays were validated with a vaccinated women group by ROC analysis and the regression analysis to distinguish the different populations of female patients. The anti-VLPs-16/18 and anti-L1-16/18 antibodies effectively detect vaccinated women (AUC = 1.0/0.79, and 0.94/0.84, respectively). The regression analysis showed that anti-VLPs-16/18 and anti-L1-16/18 antibodies were associated with the vaccinated group (OR = 2.11 × 108/16.50 and 536.0/49.2, respectively). However, only the anti-L1-16 antibodies were associated with the high-grade lesions and cervical cancer (CIN3/CC) group (OR = 12.18). In conclusion, our results suggest that anti-VLPs-16/18 antibodies are effective and type-specific to detect HPV-vaccinated women, but anti-L1-16 antibodies better differentiate the CIN3/CC group. However, a larger population study is needed to validate these results.

MOLECULAR MARKERS FOR THE DIAGNOSIS OF HIGH-RISK HUMAN PAPILLOMAVIRUS INFECTION AND TRIAGE OF HUMAN PAPILLOMAVIRUS-POSITIVE WOMEN.

Infection with high-risk human papillomavirus (HPV) increases the likelihood of developing cervical cancer (CC). A plethora of cellular processes is required to produce pre-malignant lesions, which in turn may become malignant if left untreated. Those changes are induced by viral oncoproteins, which represent an ideal target to identify the viral presence, or by some particularities of the host that ultimately promote the establishment of CC. This article describes the different methods used for HPV detection and quantification, as well as the current trend of secondary screening approaches to detect premalignant lesions and CC. In addition, we analyzed validated biomarkers and those under clinical investigation for the classification (triage) of women at risk of developing CC after an initial positive HPV test and that could be used as prognostic biomarkers for CC. The use of molecular biomarkers, together with the detection of HPV DNA sequences, provides a high impact diagnostic and prognostic tool in the detection of patients at increased risk of developing CC and also may guide their clinical management. In addition, some of those biomarkers could represent pharmacological targets for the future design of therapeutic approaches to CC treatment.

Molecular markers for the diagnosis of high-risk human papillomavirus infection and triage of human papillomavirus-positive women

ABSTRACT Infection with high-risk human papillomavirus (HPV) increases the likelihood of developing cervical cancer (CC). A plethora of cellular processes is required to produce pre-malignant lesions, which in turn may become malignant if left untreated. Those changes are induced by viral oncoproteins, which represent an ideal target to identify the viral presence, or by some particularities of the host that ultimately promote the establishment of CC. This article describes the different methods used for HPV detection and quantification, as well as the current trend of secondary screening approaches to detect premalignant lesions and CC. In addition, we analyzed validated biomarkers and those under clinical investigation for the classification (triage) of women at risk of developing CC after an initial positive HPV test and that could be used as prognostic biomarkers for CC. The use of molecular biomarkers, together with the detection of HPV DNA sequences, provides a high impact diagnostic and prognostic tool in the detection of patients at increased risk of developing CC and also may guide their clinical management. In addition, some of those biomarkers could represent pharmacological targets for the future design of therapeutic approaches to CC treatment.

Persistence of Immunity When Using Different Human Papillomavirus Vaccination Schedules and Booster-Dose Effects 5 Years After Primary Vaccination.

Background: There are limited data regarding the duration of immunity induced by different human papillomavirus (HPV) vaccination schedules and the immunogenicity of a booster dose of both bivalent HPV vaccine (bHPV) or quadrivalent HPV vaccine (qHPV). Methods: Follow-up of a nonrandomized clinical trial to evaluate the 5-year antibody persistence of the bHPV in girls (age, 9-10 years) and women (age, 18-24 years). Noninferiority of the 2-dose versus 3-dose schedule among girls was evaluated at months 54 (n = 639) and 64 (n = 990). Girls vaccinated with a 2-dose schedule of bHPV or qHPV received a booster dose of either vaccine at month 61. Immunogenicity was measured using a virus-like particle-based enzyme-linked immunosorbent assay. Geometric mean titers (GMTs) for HPV16/18 were estimated after stratification by vaccination schedule and age group. Results: At months 54 and 64, the 2-dose schedule remained noninferior to the 3-dose schedule. GMTs remained above natural infection levels across all age groups up to 64 months. After the booster, anti-HPV16/18 GMTs increased exponentially with the same pattern, regardless of vaccine administered. No safety concerns were identified with the booster dose. Conclusions: A 2-dose schedule is highly immunogenic in girls, suggesting a high immune memory. Thus, a booster dose is likely to be unprofitable, considering the low global immunization coverage. Clinical Trials Registration: NCT01717118.

The effect of a booster dose of HPV tetravalent vaccine after 51 months: implications for extended vaccination schedules / El efecto de un refuerzo de la vacuna tetravalente de VPH después de 51 meses: implicaciones para un esquema de vacunación extendido

Abstract: Objective: To asses the non-inferiority between two different vaccination schedules one month after the administration of the third dose. Materials and methods: We evaluated the anti-HPV 16/18 antibody titers induced by quadrivalent HPV vaccine administered using two different schedules in girls 9 to 10-year-old girls: a traditional (0-2-6) and an alternative (0-6-50). Blood samples were collected at month 7, 21 and 51. Results: The antibody geometric mean titer ratios one month after the application of the third dose -month 51 for the alternative and month 7 for the traditional- were 1.55 for HPV16 (95%CI, 1.15-2.08) and 1.53 for HPV18 (95%CI, 1.12-2.09). The seropositive rate was above 99% in both groups. Conclusions: The application of an alternative 3-dose schedule in 9 to 10-year-old girls induces a non-inferior immune response compared to the standard one month after the last dose. Further research is needed to understand the minimal number of doses and their timing to provide the best coverage for HPV infection.

Resumen: Objetivo: Evaluar la no inferioridad entre dos diferentes esquemas de vacunación un mes después de la administración de la tercera dosis. Material y métodos: Se evaluaron los títulos de anticuerpos anti-VPH 16/18 inducidos por la vacuna contra VPH tetravalente administrada en niñas de 9 a 10 años utilizando dos esquemas diferentes: tradicional (0-2-6) y alternativo (0-6-50). Se recolectaron muestras en los meses 7, 21 y 51. Resultados: La media geométrica de títulos de anticuerpos un mes después de la aplicación de la tercera dosis -mes 51 para la alternativa y mes 7 para el tradicional- fueron 1.55 para HPV16 (95% IC 1.15-2.08) y 1.53 para HPV18 (95% IC 1.12-2.09). La tasa de seropositividad fue superior a 99% en ambos grupos. Conclusiones: la aplicación de un esquema alternativo de tres dosis (0-6-50 meses) en niñas parece inducir una respuesta inmune no inferior al esquema tradicional un mes después de la última dosis. Se necesitan más estudios para determinar las dosis mínimas e intervalos óptimos para obtener la mejor cobertura para la infección por VPH.

MF59-adjuvanted influenza vaccine (FLUAD®) elicits higher immune responses than a non-adjuvanted influenza vaccine (Fluzone®): A randomized, multicenter, Phase III pediatric trial in Mexico.

The poor immune response elicited by trivalent influenza vaccines (TIVs) in children can be enhanced by the addition of adjuvants. This observer-blind, randomized Phase III trial assessed the immunogenicity and safety of the MF59-adjuvanted trivalent influenza vaccine FLUAD® (aTIV) and a non-adjuvanted TIV, in healthy children (aged 6 to <72 months) from 3 centers in Mexico, during the 2014-2015 season. The primary objectives were to assess the non-inferiority of aTIV to TIV, measured by geometric mean titers (GMTs), and the safety of aTIV and TIV. Seroconversion was one of several secondary objectives. In total, 287 children were enrolled. The non-inferiority criteria for GMTs and seroconversion were met for aTIV for all 3 vaccine strains. Lower bounds of the 95% confidence intervals for all 3 aTIV:TIV vaccine ratios were >2, showing that the immunogenicity of aTIV was superior to that of TIV for all 3 strains. Solicited adverse events (AEs) were experienced more frequently with aTIV than TIV by younger children (aged 6 to <36 months), but were more frequent with TIV than aTIV in older children (aged 36 to <72 months) who had been vaccinated previously. More unsolicited AEs were associated with aTIV than the TIV. All AEs were of mild or moderate severity. No deaths, serious AEs, or AEs leading to premature withdrawal were reported. Overall, aTIV was highly immunogenic and was well tolerated in healthy children 6 to <72 months of age. These results indicate that aTIV may be a beneficial addition to national pediatric vaccination programs.

The effect of a booster dose of HPV tetravalent vaccine after 51 months: implications for extended vaccination schedules.

OBJECTIVE: To asses the non-inferiority between two differ- ent vaccination schedules one month after the administration of the third dose. MATERIALS AND METHODS: We evaluated the anti-HPV 16/18 antibody titers induced by quadrivalent HPV vaccine administered using two different schedules in girls 9 to 10-year-old girls: a traditional (0-2-6) and an alterna- tive (0-6-50). Blood samples were collected at month 7, 21 and 51. RESULTS: The antibody geometric mean titer ratios one month after the application of the third dose -month 51 for the alternative and month 7 for the traditional- were 1.55 for HPV16 (95%CI, 1.15-2.08) and 1.53 for HPV18 (95%CI, 1.12-2.09). The seropositive rate was above 99% in both groups. CONCLUSIONS: The application of an alternative 3-dose schedule in 9 to 10-year-old girls induces a non-inferior immune response compared to the standard one month after the last dose. Further research is needed to understand the minimal number of doses and their timing to provide the best coverage for HPV infection.

OBJETIVO: Evaluar la no inferioridad entre dos diferentes esquemas de vacunación un mes después de la administración de la tercera dosis. MATERIAL Y MÉTODOS: Se evaluaron los títulos de anticuerpos anti-VPH 16/18 inducidos por la vacuna contra VPH tetravalente administrada en niñas de 9 a 10 años utilizando dos esquemas diferentes: tradicional (0-2-6) y alternativo (0-6-50). Se recolectaron muestras en los meses 7, 21 y 51. RESULTADOS: La media geométrica de títulos de anticuerpos un mes después de la aplicación de la tercera dosis ­mes 51 para la alternativa y mes 7 para el tradicional­ fueron 1.55 para HPV16 (95% IC 1.15-2.08) y 1.53 para HPV18 (95% IC 1.12-2.09). La tasa de seropositividad fue superior a 99% en ambos grupos. CONCLUSIONES: la aplicación de un esquema alternativo de tres dosis (0-6-50 meses) en niñas parece inducir una respuesta inmune no inferior al esquema tradicional un mes después de la última dosis. Se necesitan más estudios para determinar las dosis mínimas e intervalos óptimos para obtener la mejor cobertura para la infección por VPH.

Evaluation of the immunogenicity of the quadrivalent HPV vaccine using 2 versus 3 doses at month 21: An epidemiological surveillance mechanism for alternate vaccination schemes.

The cost of HPV vaccines and the need for 3 doses remains a barrier for their inclusion in routine vaccination schedules for girls in low and middle income countries. In a non-inferiority study, we aimed to compare the immunogenicity of a standard 3 doses and a 2 doses schedule. We enrolled 450 participants in an open-label non-randomized clinical trial to evaluate the immunogenicity induced at different ages by the licensed HPV6/11/16/18 quadrivalent vaccine in a 2 doses schedule (0-6 months, n = 150 girls aged 9-10 y) and 3 doses schedule (0, 2, and 6 months; n = 150 girls aged 9-10 y and n=150 women aged 18 to 24 years). To assess the antibody response, blood samples were obtained at Month 7 and 21 after the first vaccination from participants in all study groups. cLIA testing was performed at Merck Research Laboratories. Antibody levels were expressed as milli-Merck units (mMU) per ml. Primary outcome was non-inferiority (95% CI, lower bound >0.5) of the geometric mean titers (GMT) ratios for HPV6, HPV11, HPV16 and HPV18 antibodies 7 and 21 months after the first dose among girls receiving 2 doses compared with young women and girls receiving 3 doses. All vaccinees were seropositive for both HPV16 and HPV18 antibodies at month 7. At month 21, 98.5 and 56.6% of women 18-24 y old were seropositive for HPV16 and 18, respectively. For girls in the three doses group, seropositivity rates were 99.3 and 86.3% for HPV16 and 18, respectively. For girls in the two doses group rates were 99.3 and 70.2% for HPV16 and 18, respectively. The two doses schedule was non-inferior compared to the 3 doses schedule in same-age girls and to the group of adult women after 21 months of the first vaccine dose. Our results are in agreement with similar trials evaluating the immune response of a 2 doses schedule of both HPV vaccines, supporting the recent WHO recommendation as well as the Mexican policy to incorporate the 2 doses schedule for girls aged 9-11 y.

[The burden of cervical cancer in patients with limited access to health services]. / Repercusión del cáncer cervicouterino en pacientes con limitaciones de acceso a los servicios de salud.

BACKGROUND: Cervical cancer is caused by high-risk HPV, a sexually transmitted virus. In Mexico, this disease represents a public health problem. San Luis Potosi is located within ten states with the highest rates in the country. Indigenous women of Mexico will likely to develop cervical cancer due to inequality in access to health services and their determinants. Epidemiological studies can be supported by investigations of diverse geographical nature to undertake the identification and analysis of spatial patterns of disease. OBJECTIVE: To locate by geographical distribution of Huasteca Potosina women high-risk HPV positive to observe the burden of disease in patients with limited access to health services and propose specific primary prevention activities was made with a sample of 605 women. Cervico-vaginal specimens were taken. High-risk HPV infection was determined by hybrid capture. Age and date of the last Papanicolaou were obtained through a structured poll. It was use descriptive statistics and georeference was made in a map using the software ILWIS 3.3. RESULTS: Countyes with the highest and lowest percentages of infection were found. The prevalence of infection with high-risk HPV was 9.9% and age groups with the highest percentages of infection were in 51-60 and 41-50 years. Most women had been made the Papanicolaou at time of the present study. CONCLUSIONS: Georeferenceas like epidemiological tool for generating risk profiles allowed suggest strategies for improve prevention, early detection and control of the cervical cancer.

Conocimientos sobre virus del papiloma humano (VPH) y aceptación de auto-toma vaginal en mujeres mexicanas / Knowledge of human papilloma virus (HPV) and acceptance of vaginal self-sampling among Mexican woman

Objetivo Analizar la asociación del grado de conocimiento sobre Papillomavirus Humano y la aceptación de la auto-toma vaginal como prueba diagnóstica para la detección de cáncer cervical en mujeres mexicanas que ya han tenido la experiencia de una auto-toma vaginal en casa. Métodos Cuestionario estructurado de 22 preguntas a 690 mujeres del estado de Morelos que se realizaron la auto-toma vaginal en casa para explorar el nivel de conocimientos sobre transmisión del Papillomavirus Humano, identificación del virus como causa necesaria para cáncer cervicouterino, manifestaciones clínicas de la infección y tratamiento. Se construyó un índice de conocimientos identificando su asociación con la aceptación de la auto-toma y la confianza que las mujeres tienen en ella. El análisis estadístico incluyó regresión logística con estimación de medidas de asociación y sus respectivos intervalos de confianza al 95%. Resultados El nivel de conocimientos sobre Papillomavirus Humano presentó una asociación positiva con el grado de aceptación de la auto-toma vaginal (OR 2.9 IC 95% 1.0-5.01) y con el nivel de confianza de las mujeres (OR 2.9 IC 95% 1.8-4.67). El nivel de conocimientos se incrementa con el grado de escolaridad y es mayor en las mujeres más jóvenes. Conclusiones Para lograr una participación continuada de las mujeres con mayor riesgo de cáncer cervicouterino en la auto-toma vaginal es necesario informarlas ampliamente sobre los aspectos generales del virus, en especial a aquellas mujeres de edad avanzada, de nivel escolar y socioeconómico bajos.(AU)

Objective To analyze the relationship between the level of knowledge about human papilloma virus and the acceptance of vaginal self-sampling as a cervical cancer diagnostic test among Mexican women who have already experienced vaginal self-sampling at home. Methods A structured questionnaire consisting of 22 questions was applied to 690 women in the state of Morelos who had taken a vaginal self-sample at home. The aspects explored were the level of knowledge about transmission of the human papilloma virus, identification of the virus as a necessary cause of cervical cancer, and clinical manifestations of infection and treatment. A knowledge index was constructed, identifying the relationship between the index and the women's acceptance of self-sampling, and their degree of trust in the procedure. The statistical analysis included a logistic regression with estimates of measures of association and their respective 95% confidence intervals. Results The level of knowledge about human papillomavirus showed a positive association with the degree of acceptance of vaginal self-sampling (OR 2.9; 95% CI 1.0-5.01) and the women's level of confidence (OR 2.9; 95% CI 1.8-4.67). The level of knowledge increased with level of education and was higher in younger women. Conclusions In order for women with an increased risk of cervical cancer to continue participating in vaginal self-sampling, they must be well informed about the virus. This is especially true for older women, those with lower levels of education, and those in lower socioeconomic levels.(AU)

Overcoming barriers to HPV vaccination: non-inferiority of antibody response to human papillomavirus 16/18 vaccine in adolescents vaccinated with a two-dose vs. a three-dose schedule at 21 months.

For middle and low-income countries, the cost of HPV vaccines remains challenging. We conducted an open-label nonrandomized clinical trial evaluating immune response to the HPV-16/18 AS04-adjuvanted vaccine administered on a standard (months (M) 0-1-6) versus extended schedule (M 0-6-60) at 7, 21, 60, 72 and 120 months post-vaccination. Participants were females recruited in Morelos, Mexico: 474 girls aged 9-10 years and 500 women aged 18-24 years receiving a standard schedule, and 1026 girls aged 9-10 years receiving an extended schedule (currently the girls in the extended schedule had received only the first 2 doses). This report presents the interim analysis results for non-inferiority between the regimes conducted with the current available data at 21 months after the first dose, with serum antibodies assessed by ELISA. A pre-stated margin of non-inferiority was defined by post-vaccination geometric mean titer (GMT) ratio (upper 95% confidence interval [CI]≤2.0) between the standard and the two-dose schedule in girls at month 21. Immune response to the vaccine was strongest in adolescent girls and in the 3-dose group. Statistical non-inferiority of the two-dose versus three-dose groups was demonstrated. At 21 months, comparing the adolescent 2-dose versus 3-dose groups, the GMT ratio and 95% CI were 1.66 (1.55-1.81) and 1.67 (1.51-1.86) for HPV16 and 18, respectively. The two-dose regimen was non-inferior when compared to the three-dose response in same-age girls and with women aged 18-24 years after 21 months of follow-up. The reduction in the number of doses from the current three-dose schedule may lower overall costs associated with the vaccination and increase accessibility and compliance with the recommended dosing of the HPV vaccine.

[Knowledge of human papilloma virus (HPV) and acceptance of vaginal self-sampling among Mexican woman]. / Conocimientos sobre virus del papiloma humano (VPH) y aceptación de auto-toma vaginal en mujeres mexicanas.

OBJECTIVE: To analyze the relationship between the level of knowledge about human papilloma virus and the acceptance of vaginal self-sampling as a cervical cancer diagnostic test among Mexican women who have already experienced vaginal self-sampling at home. METHODS: A structured questionnaire consisting of 22 questions was applied to 690 women in the state of Morelos who had taken a vaginal self-sample at home. The aspects explored were the level of knowledge about transmission of the human papilloma virus, identification of the virus as a necessary cause of cervical cancer, and clinical manifestations of infection and treatment. A knowledge index was constructed, identifying the relationship between the index and the women's acceptance of self-sampling, and their degree of trust in the procedure. The statistical analysis included a logistic regression with estimates of measures of association and their respective 95% confidence intervals. RESULTS: The level of knowledge about human papillomavirus showed a positive association with the degree of acceptance of vaginal self-sampling (OR 2.9; 95% CI 1.0-5.01) and the women's level of confidence (OR 2.9; 95% CI 1.8-4.67). The level of knowledge increased with level of education and was higher in younger women. CONCLUSIONS: In order for women with an increased risk of cervical cancer to continue participating in vaginal self-sampling, they must be well informed about the virus. This is especially true for older women, those with lower levels of education, and those in lower socioeconomic levels.

Self-collection of vaginal specimens for human papillomavirus testing in cervical cancer prevention (MARCH): a community-based randomised controlled trial.

BACKGROUND: Vaginal self-sampling for human papillomavirus (HPV) DNA testing could increase rates of screening participation. In clinic-based settings, vaginal HPV testing is at least as sensitive as cytology for detecting cervical intraepithelial neoplasia (CIN) grade 2 or worse; however, effectiveness in home settings is unknown. We aimed to establish the relative sensitivity and positive predictive value for HPV screening of vaginal samples self-collected at home as compared with clinic-based cervical cytology. METHODS: We did a community-based, randomised equivalence trial in Mexican women of low socioeconomic status aged 25-65 years. Participants came from 540 medically underserved, predominantly rural communities in Morelos, Guerrero, and the state of Mexico. Our primary endpoint was CIN 2 or worse, detected by colposcopy. We used a computer-generated randomisation sequence to randomly allocate patients to HPV screening or cervical cytology. Eight community nurses who were masked to patient allocation received daily lists of the women's names and addresses, and did the assigned home visits. We referred women with positive results in either test to colposcopy. We did per-protocol and intention-to-screen analyses. This trial was registered with the Instituto Nacional de Salud Pública, Mexico, INSP number 590. FINDINGS: 12,330 women were randomly allocated to HPV screening and 12,731 to cervical cytology; 9202 women in the HPV screening group adhered to the protocol, as did 11,054 in the cervical cytology group. HPV prevalence was 9·8% (95% CI 9·1-10·4) and abnormal cytology rate was 0·38% (0·23-0·45). HPV testing identified 117·4 women with CIN 2 or worse per 10,000 (95·2-139·5) compared with 34·4 women with CIN 2 or worse per 10,000 (23·4-45·3) identified by cytology; the relative sensitivity of HPV testing was 3·4 times greater (2·4-4·9). Similarly, HPV testing detected 4·2 times (1·9-9·2) more invasive cancers than did cytology (30·4 per 10,000 [19·1-41·7] vs 7·2 per 10,000 [2·2-12·3]). The positive predictive value of HPV testing for CIN 2 or worse was 12·2% (9·9-14·5) compared with 90·5% (61·7-100) for cytology. INTERPRETATION: Despite the much lower positive predictive value for HPV testing of self-collected vaginal specimens compared with cytology, such testing might be preferred for detecting CIN 2 or worse in low-resource settings where restricted infrastructure reduces the effectiveness of cytology screening programmes. Because women at these sites will be screened only a few times in their lives, the high sensitivity of a HPV screen is of paramount importance. FUNDING: Instituto Nacional de Salud Pública, the Health Ministry of Mexico, QiAGEN Corp.

Impact of a quadrivalent HPV6/11/16/18 vaccine in Mexican women: public health implications for the region.

BACKGROUND AND AIMS: Recognition of human papillomavirus (HPV) as a necessary cause of cervical cancer (CC) led to new perspectives for its control and the demonstration of an effective primary prevention strategy through vaccination. We undertook this study to evaluate the safety, efficacy and immunogenicity of a quadrivalent HPV6/11/16/18 vaccine in Mexican women. METHODS: A total of 679 Mexican women between 18 and 23 years old participated in two Phase III double-blind, randomized, placebo-controlled clinical trials of a quadrivalent HPV 6/11/16/18 vaccine. Women were enrolled who tested negative for pregnancy and reported having four or less sexual partners during their lifetime. Vaccine or placebo was administered at day 1, month 2 and month 6. RESULTS: Among Mexican women who were naïve to the respective vaccine type at enrollment, the quadrivalent vaccine was highly efficacious, preventing 100% of HPV6/11/16/18-related cervical intraepithelial neoplasia grade 2/3, adenocarcinoma in situ, condyloma and vaginal intraepithelial neoplasia. Statistical significance was not reached for every endpoint due to the limited sample size. Vaccination was generally well tolerated and immunogenic. DISCUSSION: To widely administer the vaccine, collaborative efforts should be coordinated among public, private and local community sectors. In light of the scarce knowledge of many health professionals with respect to the primary prevention of CC, it will be necessary to educate health providers on the advantages and specific recommendations of HPV vaccines and secondary prevention. Decision making should be based on scientific evidence, allowing health professionals to provide an organized social response that supports the universal right to health.

Screen time and adiposity in adolescents in Mexico.

OBJECTIVE: To assess the association of time spent viewing television, videos and video games with measures of fat mass (BMI) and distribution (triceps and subscapular skinfold thicknesses (TSF, SSF)). DESIGN: Cross-sectional validated survey, self-administered to students to assess screen time (television, videos and video games) and lifestyle variables. Trained personnel obtained anthropometry. The association of screen time with fat mass and distribution, stratified by sex, was modelled with multivariable linear regression analysis, adjusting for potential confounders and correlation of observations within schools. SETTING: State of Morelos, Mexico. SUBJECTS: Males (n 3519) and females (n 5613) aged 11 to 18 years attending urban and rural schools in Morelos. RESULTS: In males, screen time of >5 h/d compared with <2 h/d was significantly associated with a 0.13 (95% CI 0.04, 0.23) higher BMI Z-score, 0.73 mm (95% CI 0.24, 1.22) higher SSF and 1.08 mm (95% CI 0.36, 1.81) higher TSF. The positive association of screen time with SSF was strongest in males aged 11-12 years. Sexual maturity appeared to modify the association in females; a positive association between screen time and SSF was observed in those who had not undergone menarche (P for trend = 0.04) but not among sexually mature females (P for trend = 0.75). CONCLUSION: Screen time is associated with fat mass and distribution among adolescent males in Mexico. Maturational tempo appears to affect the relationship of screen time with adiposity in boys and girls. Findings suggest that obesity preventive interventions in the Mexican context should explore strategies to reduce screen time among youths in early adolescence.

El peso, el porcentaje de grasa y la densidad mineral ósea materna son determinantes de la densidad mineral ósea en mujeres adolescentes y adultas jóvenes / Weight, fat percentage and maternal bone mineral density are determinants of bone mineral density in adolescent and young adult females

Introducción. La osteoporosis es un problema de salud pública. Es importante caracterizar los factores predisponentes a una densidad mineral ósea (DMO) baja desde la adolescencia. Material y métodos. Se estudiaron 28 binomios madre-hija. Se midió la DMO por absorciometría dual de rayos-X en diversos sitios anatómicos, obteniéndose medidas antropométricas. Se estimaron correlaciones de Pearson y modelos de regresión lineal múltiple. Resultados. El peso fue el factor más correlacionado con la DMO en todos los sitios anatómicos. En análisis múltiples, la DMO materna fue el factor más determinante de la DMO en columna (β=0.363, P =0.01); el peso (β =0.018, P < 0.01) y porcentaje de grasa (β =-0.013, P =0.02) lo fueron en cadera. Conclusiones. La herencia es el factor más determinante de la DMO en columna vertebral; el tamaño y composición corporal lo son en cadera. Controlando por peso y talla, un mayor porcentaje de grasa corporal se asocia con menor DMO en mujeres jóvenes.

Introduction. Osteoporosis is a public health problem. It is important to characterize the factors which predispose to a low bone mineral density (BMD) since adolescence. Material and methods. Twenty eight mother-daughter pairs were studied. BMD was measured by dual X-ray absorptiometry in several anatomic sites, anthropometric measures were obtained. Pearson's córrelations and multiple linear regression models were fitted. Results. Weight was the factor most correlated with BMD in all anatomic sites. In multiple analysis, maternal BMD was the most determinant factor of spinal BMD (β =0.363, P =0.01); weight (β =0.018, P < 0.01) and fat percentage (β =-0.013, P =0.02) were in the hip. Conclusions. Heredity is the most determinant factor of spinal BMD; body size and composition are in the hip. Controlling for weight and height, a greater body fat percentage is associated with a lower BMD in young women.