Carlos Hernández-Girón

High-Risk Human Papillomavirus Detection and Related Risk Factors Among Pregnant and Nonpregnant Women in Mexico

Background: Significant differences in human papillomavirus (HPV) prevalence between pregnant and nonpregnant women have been reported. Some studies suggest that physiological processes during pregnancy modify the host–immune response, increasing detectability of high-risk HPV infection as a result of viral reactivation. It remains uncertain, however, whether pregnancy has an effect on HPV DNA positivity as a result of a general lack of data and based on contradictory results found in previous epidemiologic studies. We conducted an epidemiologic study to identify differences in the prevalence of HPV infection between pregnant and nonpregnant women in Mexico. We also investigated the relationship of HPV DNA positivity with socioeconomic, gynecologic, and obstetric risk factors. Methodology: We screened pregnant and age-matched nonpregnant women for high-risk HPV infection. The study population was clients of the family medicine healthcare services of the Mexican Institute of Social Security in Cuernavaca, Morelos, Mexico. A total of 274 pregnant and 1060 nonpregnant study participants were screened for the presence of high-risk HPV DNA in self-collected specimens by the Hybrid Capture 2 test (HC2; Digene Corp., Gaithersburg, MD). Results: High-risk HPV DNA was detected in 37.2% (95% confidence interval [CI], 31–43%) of pregnant women and in 14.2% (95% CI, 12–16%) of nonpregnant women. Combining both groups for the multivariate analysis, pregnancy was associated with an increased risk for HPV infection (odds ratio, 3.5; CI, 2.7–4.9). Conclusions: Our results are consistent with other studies reporting increased high-risk HPV detection rates among pregnant women. HPV-positive status in pregnant and nonpregnant women appears to be influenced by age. The decrease in HPV positivity by number of pregnancies in both currently pregnant and nonpregnant women is consistent with a possible effect of immune protection as a result of earlier HPV infections. Despite lack of information about a woman’s history of sexual behavior, these data support the hypothesis that an alteration of immunologic responses during pregnancy may be associated with an increased risk of HPV acquisition or reactivation.

Breast cancer in Mexican women: an epidemiological study with cervical cancer control

INTRODUCTION In Mexico, breast cancer (BC) is one of the main causes of cancer deaths in women, with increasing incidence and mortality in recent years. Therefore, the aim of the study is identify possible risk factors related to BC. METHODS An epidemiological study of hospital cases of BC and controls with cervical uterine cancer (CUCA) was carried out at eight third level concentration hospitals in Mexico City. The total of 353 incident cases of BC and 630 controls with CUCA were identified among women younger than 75 years who had been residents of the metropolitan area of Mexico City for at least one year. Diagnosis was confirmed histologically in both groups. Variables were analyzed according to biological and statistical plausibility criteria. Univariate, bivariate and multivariate analyses were carried out. Cases and controls were stratified according to the menopausal hormonal status (pre and post menopause). RESULTS The factors associated with BC were: higher socioeconomic level (OR= 2.77; 95%CI = 1.77 - 4.35); early menarche (OR= 1.32; 95%CI= 0.88 - 2.00); old age at first pregnancy (>31 years: OR= 5.49; 95%CI= 2.16 - 13.98) and a family history of BC (OR= 4.76; 95% CI= 2.10 - 10.79). In contrast, an increase in the duration of the breastfeeding period was a protective factor (>25 months: OR= 0.38; 95%CI= 0.20 - 0.70). CONCLUSIONS This study contributes to the identification of risk factors for BC described in the international literature, in the population of Mexican women. Breastfeeding appears to play an important role in protecting women from BC. Because of changes in womens lifestyles, lactation is decreasing in Mexico, and young women tend not to breastfeed or to shorten the duration of lactation.

Epidemiologic Panorama of Stomach Cancer Mortality in Mexico

BACKGROUND Annually, there are more than 6 million deaths from a type of malignant neoplasia worldwide. In developing countries, the highest rates of incidence of malignant neoplasias are uterine cervical cancer, stomach, lung, esophagus, pharynx, and liver cancers. Recent estimates on the incidence of cancer worldwide show that, in 1990, stomach cancer (SC) was the second most frequent type of cancer (900,000 new cases annually). Rates of incidence have decreased consistently in nearly all areas of the world. In Mexico, however, rates of incidence and mortality have increased gradually between 1980 and 1997; in 1995, 4,685 people died of SC in Mexico. This report presents a descriptive analysis of SC mortality in Mexico. METHODS A mortality database edited from the electronic files of the National Institute of Informatics, Statistics and Geography (INEGI) in Mexico was used; population denominators were edited by the Mexican National Population Council (Conapo). Adjusted mortality rates, taking as standard of reference the population of Mexico City by sex, year, and 10-year age groups were calculated as well as the sex ratio for the 1980-1997 period. To evaluate the magnitude of risks by state, the standardized mortality ratio (SMR) was calculated; prematurity was evaluated through the potential lost-life years index (PLLYI). The analysis was carried out using the Excel and Stata 5.0 software programs. RESULTS During the years from 1980 to 1997, in Mexico the total number of deaths from SC was 76,315. The male:female ratio was 1.2:1.0. SMR by state showed that the states of Yucatán, Sonora, Zacatecas, Michoacán, and Chiapas had higher mortality rates. The PLLYI was higher for males in the states of Chiapas, Sonora, Chihuahua, Zacatecas, and Southern Baja California, and higher for females in Chiapas, Oaxaca, Yucatán, Puebla, and Campeche. CONCLUSIONS World statistics on mortality caused by SC suggest a decreasing trend. Findings for this study show an increase in the adjusted mortality rates by SC during the 1980-1997 period in Mexico. However, when analyzing the different indicators that reveal risks, magnitude, and prematurity of mortality, there is a differential trend in mortality by sex that includes regional patterns probably related to different socioeconomic levels.

Características de comportamiento sexual en hombres de la Ciudad de México

Objetivo. Determinar las principales caracteristicas de comportamiento sexual en hombres de la Ciudad de Mexico, incluyendo numero de parejas sexuales, antecedentes de enfermedades de transmision sexual (ETS) y creencias acerca del sindrome de inmunodeficiencia adquirida (SIDA). Material y metodos. Durante 1995 se realizo un estudio epidemiologico transversal, basado en un muestreo multietapico por conglomerados; se entrevisto a 1 377 hombres de 15 a 49 anos de edad, a quienes se les aplico un cuestionario estructurado. Para el analisis estadistico de los datos se realizaron pruebas de significancia como t de Student y ji². Resultados. Entre los entrevistados la media de edad fue de 34.5 anos (DE= 7.5 anos), y la media de inicio de relaciones sexuales de 17.7 anos (DE= 2.8 anos). La proporcion global de uso de condon durante la ultima relacion sexual fue de 24.6%; de acuerdo con el tipo de pareja sexual femenina en el ultimo ano, 18.8% lo usaron con parejas regulares y 62.5% con multiples parejas. El 2% refirio sintomas sugestivos de uretritis gonococica. Finalmente 97.5% refirio saber que significaba la palabra SIDA y conocer ciertas medidas protectoras contra la infeccion. Conclusiones. En este estudio se identificaron caracteristicas de comportamiento sexual riesgoso para adquirir y transmitir alguna ETS, como tener multiples parejas sexuales, no usar el condon y presentar antecedentes de ETS.

Factors associated with condom use in the male population of Mexico City

Sexually transmitted diseases (STDs) are an important public health problem, due to their medical, social and economic repercussions. Therefore, more knowledge is needed about the sexual behaviour that promotes their spread, in order to improve control and prevention strategies. Our aim was to determine the frequency of male condom use associated with sexual behaviour factors, a history of and knowledge about STDs in a sample of the male population in Mexico City. During 1994 a cross-sectional epidemiological study was carried out, using multi-stage sampling with conglomerates, in 1377 men from 15 to 49 years old. The mean age was 34.5 years (SD 7.5 years). Mean age at first sexual relations was 17.7 years (SD 2.8 years). The global proportion of condom use during the last sexual relation was 24.6%; use according to type of female sex partner in the last year was 18.8% with regular partners and 62.5% with occasional partners. The principal predictors of male condom use, identified through statistical modelling, were: younger age (<25 years), middle and high education level (>9 years), middle and high socioeconomic level and type of sexual partners (occasional and regular). This population has risk factors for acquiring and transmitting some STDs, such as occasional sexual partners and a history of STDs. Characteristics which are important in relation to male condom use were identified, such as age (younger than 35), education (complete junior high school or more) and type of sexual partners (occasional and regular).

Prevalencia de infección por virus de papiloma humano (VPH) de alto riesgo y factores asociados en embarazadas derechohabientes del IMSS en el estado de Morelos

Objective. Some studies suggest the possibility that the physiological process of pregnancy modifies certain characteristics of the mother, increasing the risk of both, infection and persistence of infection with HPV. This association, however, has not been firmly established. This study seeks to determine the prevalence of oncogenic HPV infecton in a sample of pregnant Mexican women and its possible risk factors. Material and Methods. A cross-sectional study was conducted using a sample of 274 pregnant women sought first level of care services during the year 2000 at the antenatal clinic of the Mexican Institute of Social Security (IMSS) in Cuernavaca, Morelos, Mexico. Samples of vaginal cells were obtained through self-collected specimens, for the high-risk HPV DNA test using the Hybrid Capture 2 test (HC2). A structured questionnaire was administered regarding sociodemographic, gynecologic, obstetric and sexual behavior characteristics. Results. The mean age was 25.7 years. The average time of pregnancy when the study was conducted was 6 months. The principal risk factors associated with high-risk HPV infection were: ages between 20 and 29 (OR= 2.82; CI95% 1.02‐7.76)), age 30 and over (OR= 6.85,CI95% 1.22-38.2); partners having sexual relatio

Prostate cancer mortality trends in Mexico, 1980–1995

In Mexico, prostate cancer (PC) is the second highest cause of mortality by cancer in men. In 1991, there were 2,473 deaths, with a crude rate of 5.66 cases per 100,000 men age 40 or over. For this same year, the ratio of proportional mortality to the total number of malignant tumors was 12.6%. Our objectives were to determine the trends and geographic distribution of mortality for PC in Mexico for 1980–1995.

Vitamin D receptor gene polymorphisms are associated with multiple sclerosis in Mexican adults

BACKGROUND Multiple sclerosis (MS) is the most prevalent autoimmune inflammatory demyelinating disease of the central nervous system (CNS) in young adults. More than 50 genomic regions have been associated with MS susceptibility. Due the important immune-modulating properties of Vitamin D, Vitamin D receptor (VDR) gene polymorphisms - which interfere with the actions of Vitamin D- could be related to increased risk of MS. METHODS We studied 120 patients fulfilling the McDonald criteria for MS (81 females and 39 males) and 180 healthy unrelated controls, nested in a case-Control study, and were recruited from the National Institute of Neurology and Neurosurgery, Manuel Velasco Suárez in Mexico City. Genotyping of VDR gene polymorphisms BsmI (rs1544410) and TaqI (rs731236) was performed using TaqMan SNP Genotyping Assay which consists of a predesigned mix of unlabeled polymerase chain reaction (PCR) primers and the TaqMan minor groove binding group (MGB) probe (FAM dye-labeled). RESULTS There was a statistically significant, positive association between MS and the T/T genotype of BsmI polymorphism (OR=4.15; 95%CI 1.83-9.39), showing also a significant positive trend across genotypes (p<0.01). This association was also present evaluating the recessive inheritance model of the polymorphism (OR=3.91; 95%CI 1.77-8.64). When evaluating the association by alleles, the statistically significant positive association seen by genotypes was confirmed in the T allele carriers, showing an OR of 1.83 (95%CI 1.27-2.65) for MS. CONCLUSIONS We found a positive association of the genetic VDR polymorphisms TaqI (rs731236) and BsmI (rs1544410), with the risk of MS in a sample of Mexican adults.

Uso de servicios de planificación familiar de la Secretaría de Salud, poder de decisión de la mujer y apoyo de la pareja

OBJETIVO: Identificar la influencia de las caracteristicas reproductivas y el empoderamiento femenino en el uso de servicios de planificacion familiar (PF). MATERIAL Y METODOS: Diseno de casos y no casos pareado por controles vecindarios (147 usuarias y 146 no usuarias de servicios de PF de la Secretaria de Salud durante 2003), en dos municipios del estado de Guanajuato, Mexico. Analisis logistico multivariado para identificar diferencias entre usuarias y no usuarias. RESULTADOS: El uso de servicios de PF se asocio positiva y significativamente con poder de decision de la mujer (alto: RM=3.2; IC95% 1.4-7.4); comunicacion con la pareja para el uso de metodos de PF (RM =3.5; IC95% 1.4-9.3), y numero de embarazos en su vida (> 6 hijos: RM =4.4; IC95% 1.4-13.8). CONCLUSIONES: El desarrollo de estrategias que involucren a los hombres y que, por otra parte, fomenten y fortalezcan el empoderamiento femenino, puede contribuir a una mayor utilizacion de servicios de PF.

Mortalidad materna en Guatemala: diferencias entre muerte hospitalaria y no hospitalaria

Objective: To estimate the association between obstetric and socio-demographic characteristics and risk factors related to intra- and extra-hospital maternal mortality in Guatemala during the year 2000. Materials and Methods: A cross-sectional epidemiologic study was carried out in 649 maternal mortality (MM) cases that occurred in Guatemala during 2000, comparing characteristics of intra- and extrahospital maternal deaths. Multivariate statistical analysis was conducted using Stata 7.0 software. Results: Out of 649 registered MM cases, 270 (41.6%) were classified as intrahospital MM and 379 (58.4%) as extra-hospital MM. A larger proportion of deaths occurred in women over 35 years of age (29.28%), those of indigenous ethnicity (65.49%), married or cohabiting (87.83%), who had unpaid employment (94.78%), and without formal education (66.56%). Compared with intra-hospital MM cases, the risk of extra-hospital MM was greater among indigenous women (OR 3.4; CI95% 2.8-5.3), those who had unpaid employment (OR 8.95; CI95% 1.7-46.4), a low level of formal education (OR 1.96; CI95% 1.0-3.8) and hemorrhaging as the immediate cause of death (OR 4.28; CI95% 2.3-7.9).Conclusions: Although some characteristics of intra- and extra-hospital MM cases are similar, a greater proportion of deaths were extra-hospital. This could be related to the high percentage of the population that lives in rural or marginalized areas, which in addition to certain cultural aspects (related to the fact that most of the population is indigenous) may impede access to health services. The results of this study can be useful for determining intervention strategies to prevent maternal mortality in intra- and extra-hospital contexts in Guatemala.