Factores de riesgo asociados a mortalidad por COVID-19 en México / Risk factors associated with COVID-19 mortality in Mexico

Resumen Antecedentes: El 31 de diciembre de 2019, se inició una de las pandemias más graves de los últimos tiempos. Se ha descrito que ciertas condiciones de salud, como la obesidad y la diabetes mellitus, están relacionadas con desenlaces desfavorables por COVID-19. Objetivo: Identificar factores asociados a mortalidad en pacientes con COVID-19. Material y métodos: Cohorte retrospectiva de 998 639 pacientes. Se analizaron las características sociodemográficas y clínicas de los pacientes, y se compararon supervivientes con fallecidos. Se utilizó el modelo de riesgos proporcionales de Cox para la identificación de variables predictivas de defunción por COVID-19. Resultados: Entre los fallecidos, los hombres representaron 64.3 % y las mujeres 35.7 %, diferencia que resultó estadísticamente significativa. Las personas con más de 80 años presentaron un riesgo 13 veces mayor de morir por COVID-19 (IC 95 % = 12.469,13.586) y la enfermedad renal crónica, un riesgo de 1.5 (IC 95 % = 1.341, 1.798); la diabetes mellitus tuvo un riesgo de 1.25 (IC 95 % = 1.238,1.276). Conclusiones: La edad, el sexo, la diabetes mellitus y la obesidad resultaron ser entidades predictivas de muerte por COVID-19. Se sugiere más investigación relacionada con enfermedad pulmonar obstructiva crónica, enfermedades cardiovasculares, tabaquismo y embarazo.

Abstract Background: On December 31, 2019, one of the most serious pandemics in recent times made its appearance. Certain health conditions, such as obesity and diabetes mellitus, have been described to be related to COVID-19 unfavorable outcomes. Objective: To identify factors associated with mortality in patients with COVID-19. Material and methods: Retrospective cohort of 998,639 patients. Patient sociodemographic and clinical characteristics were analyzed, with survivors being compared with the deceased individuals. Cox proportional hazards model was used to identify variables predictive of COVID-19-associated mortality. Results: Among the deceased patients, men accounted for 64.3%, and women, for 35.7%, with the difference being statistically significant. Subjects older than 80 years had a 13-fold higher risk of dying from COVID-19 (95% CI = 12,469, 13,586), while chronic kidney disease entailed a risk 1.5 times higher (95% CI = 1,341, 1,798), and diabetes mellitus involved a risk 1.25 times higher (95% CI = 1.238,1.276). Conclusions: Age, sex, diabetes mellitus and obesity were found to be predictors of COVID-19 mortality. Further research related to chronic obstructive pulmonary disease, cardiovascular diseases, smoking and pregnancy is suggested.

Effect of a texture-modified and controlled bolus volume diet on all-cause mortality in older persons with oropharyngeal dysphagia: Secondary analysis of a randomized controlled trial.

BACKGROUND: Oropharyngeal dysphagia (OD) is common among older adults. Some studies have evaluated the efficacy of a texture-modified diet on mortality but with short-term follow-up. We aimed to evaluate the effect of a texture-modified diet and controlled bolus volume on all-cause mortality after 12 months in older persons with OD. METHODS: This secondary analysis of a randomized clinical trial included patients aged ≥60 years with a diagnosis of OD. They were concurrently and randomly assigned to receive either a texture-modified food diet and controlled bolus volume (intervention group) or standard treatment (control group) with 12 months of follow-up. Secondary outcomes were oral intake, weight, handgrip strength, phase angle, and aspiration pneumonia. Kaplan-Meier analysis and the Cox proportional hazards model were used for mortality analysis. RESULTS: A total of 127 participants (intervention group: 64 and control group: 63) were recruited, with a mean age of 76 years. The probability of all-cause mortality was significantly lower in the intervention group (n = 8, 12%) than in the control group (n = 18, 29%) (hazard ratio = 0.36 [95% CI = 0.16-0.86]; P = 0.01). There were 5 (7.9%) and 10 (16.1%) aspiration pneumonia events in the intervention and control groups, respectively (not significant) in 12 months of follow-up. Changes were observed in protein consumption (P = 0.01), body weight (P = 0.04), body mass index (P = 0.004), handgrip strength (P = 0.02), and phase angle (P = 0.04) between the treatment groups. CONCLUSION: Compared with the standard treatment, the dietary intervention improved efficacy by limiting nutrition complications, aspiration pneumonia, and all-cause mortality.

COVID-19 Outbreak during Summer Courses at an Elementary School.

Due to the COVID-19 emergency, face-to-face classes were suspended. After the vaccination of teachers and to mitigate educational backwardness, the schools have begun to reopen with protocols established by the government. Here, we investigated the COVID-19 outbreak in summer courses during the reopening of a private elementary school in July 2021. We report confirmed cases of COVID-19 in staff members, students, and their families. A total community of 290 people was part of this study, and we built the contact network. The clinical features of all cases are described. We used the methodology of cases and contacts. The index case was identified by epidemiological tracking, and containment measures were activated, as well as further infection chains in the setting. We estimate the attack rate for staff members at 15.68% (95% CI 7.0-28.6), students at 12.24% (95% CI 4.6-24.8), and family members at 2.6% (95% CI 0.8-6.0). An incubation period of 48-72 h was determined. A student-teacher-student-family transmission sequence was identified. The area where the infection was identified was the school swimming pool, an area where face masks are not worn or, in some cases, inadequately used. Finally, we continue with intermittent staff testing and early detection actions, reinforcing prevention measures, environmental control, cleaning, and educational interventions with students regarding the implementation of preventive measures through classes led by school health staff.

Diagnostic performance of questionnaires to identify individuals with impaired fasting glucose in Mexican adult population.

AIMS: To evaluate the diagnostic performance of five questionnaires to identify impaired fasting glucose (IFG) in Mexican adult population. METHODS: The study included 23,311 subjects from five cohorts, three composed of individuals who sought medical advice in their first level clinics or participated in research studies and two representative surveys of the Mexican population. The reference standard was IFG which was defined as a fasting glucose ≥ 100 mg/dL. Diagnostic performance was evaluated with specificity, sensitivity, positive and negative predictive values, area under the curve, and the proportion of correctly classified individuals. RESULTS: The prevalence of IFG ranged from 14.4 to 48.1 % across the cohorts. Diagnostic performance of the questionnaires varied in each cohort depending on IFG prevalence. The questionnaires designed by Rojas, American Diabetes Association and International Diabetes Federation had the best performance considering the correct classification (>66.0 %) of subjects in all cohorts. However, Rojas' questionnaire had the best balance between sensitivity and specificity across the cohorts. CONCLUSION: In the Mexican population, considering different scenarios, the Rojas' questionnaire had the best diagnostic performance. The implementation of questionnaires for the identification of prediabetes and undiagnosed diabetes requires further study in specific populations.

Importance of Microbiome of Fecal Samples Obtained from Adolescents with Different Weight Conditions on Resistance Gene Transfer.

Antimicrobial resistance (AMR) is a relevant public health problem worldwide, and microbiome bacteria may contribute to the horizontal gene transfer associated with antimicrobial resistance. The microbiome of fecal samples from Mexican adolescents were analyzed and correlated with eating habits, and the presence of AMR genes on bacteria in the microbiome was evaluated. Fecal samples from adolescents were collected and processed to extract genomic DNA. An Illumina HiSeq 1500 system was used to determine resistance genes and the microbiome of adolescents through the amplification of gene resistance and the V3-V4 regions of RNA, respectively. Analysis of the microbiome from fecal samples taken from 18 obese, overweight, and normal-weight adolescents revealed that the Firmicutes was the most frequent phylum, followed by Bacteroidetes, Actinobacteria, Proteobacteria and Verrucomicrobia. The following species were detected as the most frequent in the samples: F. prausnitzii, P. cori, B. adolescentis, E. coli and A. muciniphila. The presence of Bacteroides, Prevotella and Ruminococcus was used to establish the enterotype; enterotype 1 was more common in women and enterotype 2 was more common in men. Twenty-nine AMR genes were found for ß-lactamases, fluoroquinolones, aminoglycosides, macrolide, lincosamides, streptogramin (MLS), tetracyclines and sulfonamides. The presence of microorganisms in fecal samples that harbor AMR genes that work against antimicrobials frequently used for the treatment of microbial infections such as b-lactams, macrolides, aminoglycosides, MLS, and tetracyclines is of great concern, as these organisms may be an important reservoir for horizontal AMR gene transfer.

Factors Associated with Recovered Functionality After Hip Fracture in Non-Institutionalized Older Adults: A Case-Control Study Nested in a Cohort.

PURPOSE: To identify factors associated with recovered functionality after a hip fracture in a sample of older adult patients. PATIENTS AND METHODS: Nested case-control study in a cohort. Older adults (60 years or older) with a hip fracture were recruited between May 2017 and October 2018. The Barthel scale was used to measure performance in activities of daily living (ADL). A questionnaire was applied to collect information about demographic, clinic, psychological and social variables, and anthropometric measurements were taken. A logistic regression model was built to analyze various factors related to recovered functionality. RESULTS: A total of 346 older adults with a hip fracture were studied (n=173 cases and n=173 controls); 69.4% (n=240) women and 30.6% (n=140) men. Mean age was 79.4 years (±8.7) overall; for cases, 77.4 (±7.9) years and for controls, 81.4 (±9.0). Mean schooling was 6.3 (± 4.3) years. Recovered functionality was associated with normal nutritional status (OR 4.81, 95% CI = 2.54-9.12), absence of heart disease (OR 4.08, 95% CI = 1.48-11.20), self-efficacy for ADL (OR 4.07, 95% CI = 2.15-7.72), absence of depressive symptoms (OR 2.99, 95% CI = 1.69-5.28), prior functionality (OR 2.83, 95% CI = 1.51-5.31), high socioeconomic level (OR 2.41, 95% CI = 1.24-4.65) and transcervical fracture (OR 2.34, 95% CI = 1.05-5.22). CONCLUSION: In older adults who have suffered a hip fracture, clinical, psychological, and demographic characteristics are associated with recovered functionality. These factors should be considered as a priority in the care of older adults who have experienced hip fractures.

Histoplasma capsulatum and Pneumocystis jirovecii coinfection in hospitalized HIV and non-HIV patients from a tertiary care hospital in Mexico.

BACKGROUND: Histoplasma capsulatum and Pneumocystis jirovecii are respiratory fungal pathogens that principally cause pulmonary disease. Coinfection with both pathogens is scarcely reported. This study detected this coinfection using specific molecular methods for each fungus in the bronchoalveolar lavage (BAL) of patients from a tertiary care hospital. MATERIALS AND METHODS: BAL samples from 289 hospitalized patients were screened by PCR with specific markers for H. capsulatum (Hcp100) and P. jirovecii (mtLSUrRNA and mtSSUrRNA). The presence of these pathogens was confirmed by the generated sequences for each marker. The clinical and laboratory data for the patients were analyzed using statistical software. RESULTS: The PCR findings separated three groups of patients, where the first was represented by 60 (20.8%) histoplasmosis patients, the second by 45 (15.6%) patients with pneumocystosis, and the last group by 12 (4.2%) patients with coinfection. High similarity among the generated sequences of each species was demonstrated by BLASTn and neighbor-joining algorithms. The estimated prevalence of H. capsulatum and P. jirovecii coinfection was higher in HIV patients.

Actitudes hacia la homoparentalidad: Validación psicométrica de dos escalas en una muestra de estudiantes mexicanos / Atitudes em relação à homoparentalidade: validação psicométrica de duas escalas numa amostra de estudantes mexicanos / Attitudes Towards Homoparentality: Psychometric Validation of two Scales in a Sample of Mexican Students

Introducción: La legalización del llamado matrimonio igualitario, y de la adopción de menores por parejas homosexuales, es un fenómeno reciente y que debe ser estudiado, para lo cual es necesario contar con medidas confiables que permitan dar cuenta de cómo la sociedad percibe esta nueva configuración familiar. Objetivo: Determinar las propiedades psicométricas de dos escalas: Actitudes frente a las familias Homoparentales (AFFH); y creencias acerca del ajuste de los niños de familias homoparentales (CANFH). Metodología: La AFFH, con 20 reactivos, fue diseñada para dar cuenta de las actitudes hacia las familias homoparentales. La CANFH tiene 14 reactivos organizados en las subescalas de oposición individual (OI) y oposición normativa (ON). Ambas escalas tienen afirmaciones que deben ser respondidas con opciones tipo Likert que van del 1 totalmente de acuerdo, al 5 totalmente en desacuerdo. La CANFH fue aplicada a 170 estudiantes universitarios (78 (46%) hombres, 92 (54%) mujeres. Media de edad: 18.4 DE+0.94), y la AFFH a 88 (35 (40%) hombres, 53 (60%) mujeres. Media de edad: 18.2 DE+0.84). Se determinaron las propiedades psicométricas por medio de análisis factorial y de consistencia interna. Resultados: La AFFH resultó con un α=0.91; los reactivos se organizaron en dos factores que explican 46.14% de la varianza. En el caso de la CANFH se confirmó la estructura factorial de dos subescalas explicativas de 65.49% de la varianza y con un α=0.94. Conclusiones: Los datos indican que ambas escalas poseen las propiedades psicométricas adecuadas para medir las actitudes de estudiantes mexicanos hacia las familias homoparentales y hacia los efectos que estas puedan tener en los menores adoptados...(AU)

Introduction: Same-sex marriage and adoption legalization constitute a growing and relatively new research field. Its study needs reliable and valid measures that allow to understand the society's perception about this new family order. Objective: Assess the psychometric properties of two scalesdevised to measure same-sex parenting attitudes: Attitudes toward Same-sex Families Scale (AFFH for its acronym in Spanish), and Scale on Beliefs about Children's Adjustment in Same-sex families (CANFH in Spanish). Methodology: AFFH scale is a 20-item measure designed to account for attitudes towards same-sex families. CANFH is a 14-item measure consisting of two scales, Individual Opposition (IO) and Normative Opposition (NO). Both are Likert scales with five response options (1. Strongly Agree to 5. Strongly Disagree). The CANFH was answered by 170 college students (78 (46%) males, 92 (54%) females; Average age: 18.4 SD 0.94), and the AFFH by 88 college students (35 (40%) males, 53 (60%) females, average age: 18.2 SD + 0.84). Results: AFFH items were organized into two factors that explained 46.14% of variance with a Cronbach's alpha of 0.91. CANFH items were grouped in a two factors structure that explained 65.49% of the variance (α = 0.94). Conclusions: CANFH and AFFH scales have adequate psychometric properties to measure Mexican college students' attitudes toward same-sex families and to assess the beliefs about children's adjustment in same-sex families...(AU)

Introdução: A legalização do chamado casamento do mesmo sexo e adoção de crianças por casais homossexuais, é um fenômeno recente, que deve ser estudado, para a qual é necessário ter medidas confiáveis que permitem ver como a sociedade percebe esta nova configuração familiar. Objetivo: determinar as propriedades psicométricas de duas escalas: Atitudes para com as famílias homoparentais (AFFH); e as crenças sobre o equilíbrio das crianças de famílias homoparentais. Metodologia: O AFFH, com 20 itens, foi projetado para explicar atitudes das famílias homoparentais. O CANFH tem 14 reagentes organizados em sub-escalas de oposição individual (OI) e oposição regulamentar (ON). Ambas as escalas são declarações que devem ser respondidas com opções de tipo Likert, entre 1 que significa estar de acordo e 5 que discorda totalmente (CANFH). O CANFH foi aplicado a 170 estudantes universitários (78 (46%) do sexo masculino, 92 (54%) mulheres com idade média: 18.4 + 0.94), e AFFH a 88 (35 (40%) do sexo masculino, 53 (60% ) mulheres média de idade. 18.2 + 0.84). Foram determinadas as propriedades psicométricas por meio de análise fatorial e consistência interna. Resultados: A AFFH foi α = 0.91 com reagentes foram organizados em dois fatores que explicam 46.14% da variância. No caso de a estrutura fatorial CANFH dois explicativa 65.49% da variância e um α = 0,94 subescalas foi confirmada. Conclusões: Os dados indicam que ambas as escalas têm o direito de medir as atitudes dos estudantes em relação homoparentais famílias mexicanas e para os efeitos que podem ter sobre as crianças adotadas propriedades psicométricas...(AU)

Common epitopes in LPS of different Enterobacteriaceae are associated with an immune response against Escherichia coli O157 in bovine serum samples.

Epidemiological studies in both humans and animals conducted in Mexico have shown that the isolation frequency of Escherichia coli O157 : H7 is low. In a previous study, IgG antibodies against E. coli O157, O7 and O116 LPS were found in serum samples from children and adults with no previous history of E. coli O157 : H7 infection. The present study was designed to determine whether a similar immune response against E. coli O157 : H7 and other antigenically related bacteria was present in bovine serum samples. A total of 310 serum samples from different herds in Mexico was analysed by microagglutination assays against different enterobacterial antigens, including E. coli O157. Microagglutination assays were positive against E. coli O7 (55 %), O116 (76 %) and O157 (36 %), Escherichia hermannii (15 %), Salmonella enterica serotype Urbana (14 %) and Salmonella enterica subsp. arizonae (40 %). These results were confirmed using a specific ELISA with purified LPS. A positive reaction was observed against the LPS of E. coli O7 (29 %), O116 (12 %) and O157 (22 %), E. hermannii (4 %), Salmonella Urbana (13 %) and S. enterica subsp. arizonae (12 %). Serum absorption studies of positive serum samples indicated the existence of at least three common epitopes shared by the LPS of E. coli O7, O116 and O157, and two others between E. coli O157 and Salmonella Urbana and S. enterica subsp. arizonae. A bactericidal assay against E. coli O157 : H7 using 31 bovine serum samples was performed, and 22 (71 %) of these serum samples gave positive results. The data demonstrated that bovine serum showed a response against different enterobacteria, including E. coli O157, and that this response could be due to the presence of shared epitopes in the LPS of these organisms.

Epidemiologic and ultrasonographic study of echinococcosis in a community in the state of Mexico.

No epidemiologic study for cystic echinococcosis in México has yet been described. The objective of this work was to determine the prevalence and distribution of human echinococcosis in a community of the state of México and its probable risk factors. A cross-sectional study was performed; household census was used to randomly select houses. The larval stage of Echinococcus was searched by ultrasound in liver, spleen, and kidney. A questionnaire was used for the investigation of risk factors. The study was performed with 401 persons, 64% were female. The prevalence of echinococcosis was 0.75%. Cases were distributed in the same sector of the community. The close distribution of cases suggests the same exposure source. There were 426 dogs in the community; feces were collected from 414 of these in search of cestode eggs. After treatment, 3 dogs had Taenia pisiformis but none had Echinococcus. This paper pioneers the search of human echinococcosis in México because it provides evidence of the presence of this tissue parasite at the community level.

Insecticide and community interventions to control Triatoma dimidiata in localities of the State of Veracruz, Mexico.

Three different interventions to control Triatoma dimidiata in the State of Veracruz were implemented: X-1 = whole dwelling spraying, X-2 = middle wall spraying, X-3 = household cleaning. Cyfluthrin was sprayed 3 times with 8 month intervals. After each spraying, insects were collected and sent to the laboratory to be recorded and to determine genus and species of the adult triatomine bugs, and nymphs were counted. Trypanosoma cruzi presence was determined. With X-1, the infestation, colonization, and natural infection indexes were reduced to 0% in the 3 localities, with respect to t0. With X-2, the infestation index was reduced to 10% at t3 in 3 localities; the colonization index was reduced to 0% in only 1 locality at t3, and the natural infection index was reduced to 0% at t3. With X-3 the 3 indexes were not effectively reduced but they decreased with respect to the baseline study. Insecticide application to the whole dwelling is a more efficient intervention than its application to only the lower half of the walls and to the cleaning of houses.

Insecticide and community interventions to control Triatoma dimidiata in localities of the State of Veracruz, Mexico

Three different interventions to control Triatoma dimidiata in the State of Veracruz were implemented: X-1 = whole dwelling spraying, X-2 = middle wall spraying, X-3 = household cleaning. Cyfluthrin was sprayed 3 times with 8 month intervals. After each spraying, insects were collected and sent to the laboratory to be recorded and to determine genus and species of the adult triatomine bugs, and nymphs were counted. Trypanosoma cruzi presence was determined. With X-1, the infestation, colonization, and natural infection indexes were reduced to 0 percent in the 3 localities, with respect to t0. With X-2, the infestation index was reduced to 10 percent at t3 in 3 localities; the colonization index was reduced to 0 percent in only 1 locality at t3, and the natural infection index was reduced to 0 percent at t3. With X-3 the 3 indexes were not effectively reduced but they decreased with respect to the baseline study. Insecticide application to the whole dwelling is a more efficient intervention than its application to only the lower half of the walls and to the cleaning of houses.

[Mortality risk factors in the child of a toxemic mother]. / Factores de riesgo de mortalidad en el hijo de madre toxémica.

OBJECTIVE: To determine risk factors of mortality in the infant of a toxemic mother. MATERIAL AND METHODS: A case-controls study, single products only, of 28-42 weeks of gestation; cases were either stillborn and neonatal deaths. Where controls were survivors. RESULTS: There were 57 cases and 114 controls. Significant risk factors were: eclampsia (OR = 4.25, 95%CI 1.76-10.39, p = 0.0002), placental detachment (OR = 8.13, 95%CI 2.29-31.4, p = 0.00007), general anesthesia (OR = 5.32, 95%CI 1.74-16.51, p = 0.0005), respiratory distress syndrome (OR = 23.68, 95%CI 3.31-478 p = 0.00004), mechanic ventilation (OR = 334, 95%CI 42.63-7084, p = 0.000000001), peri-intraventricular hemorrhage (OR = 64.57, 95%CI 8.36-1361, p = 0.0000001), acute renal failure (OR = 26.13, 95%CI 5.21-177, p = 0.0000002) and pulmonary hemorrhage (OR = 8.40, 95%CI 2.71-27.11, p = 0.000006). We observed as protective factors: high maternal educational level (OR = 0.110, 95%CI 0.01-0.66, p = 0.02), intrauterine malnutrition (OR = 0.39, 95%CI 0.18-0.84, p = 0.008) and transient tachypnea of the newborn (OR = 0.021, 95%CI 0.00-0.15, p = 0.00000001). CONCLUSIONS: We found as maternal risk factors: eclampsia; premature placental detachment; general anesthesia, and maternal death, in the newborns they were respiratory distress syndrome, mechanical ventilation and peri-intraventricular hemorrhage. The finding of protection factors is interesting.

Factores de riesgo de mortalidad en el hijo de madre toxémica / Mortality Risk Factors in the Child of a Toxemic Mother

Objetivo. Determinar los factores de riesgo de mortalidad en el hijo de madre toxémica. Material y métodos. Estudio de casos y controles en hijos de toxémicas, de producto único, de 28 a 42 semanas de gestación; los casos fueron los fallecidos y los controles los sobrevivientes. Resultados. Fueron 57 casos y 114 controles. Los factores de riesgo significativos: eclampsia (RM= 4.25, IC95% 1.76-10.39, p= 0.0002), desprendimiento placentario (RM= 8.13, IC95% 2.29-31.4, p= 0.00007), anestesia general (RM= 5.32, IC95% 1.74-16.51 p= 0.0005), síndrome de dificultad respiratoria (RM= 23.68, IC95% 3.31-478 p= 0.00004), ventilación mecánica (RM= 334, IC95% 42.63-7084, p=0.000000001), hemorragia peri-intraventricular (RM= 64.57, IC95% 8.36-1361, p = 0.0000001), insuficiencia renal aguda (RM= 26.13, IC95% 5.21-177, p= 0.0000002 ) y hemorragia pulmonar (RM= 8.40, IC95% 2.71-27.11, p= 0.000006). Se detectaron como factores protectores: alta escolaridad materna (RM= 0.110, IC95% 0.01-0.66, p= 0.02), desnutrición in útero (RM= 0.39, IC95% 0.18-0.84, p= 0.008) y taquipnea transitoria del recién nacido (RM= 0.021, IC95% 0.00-0.15, p= 0.00000001 Conclusiones. Los factores de riesgo maternos fueron: eclampsia, desprendimiento placentario, anestesia general y muerte materna; en el producto: síndrome de dificultad respiratoria, ventilación mecánica y hemorragia peri-intraventricular. Es interesante el hallazgo de los factores de protección.

Objective. To determine risk factors of mortality in the infant of a toxemic mother. Material and Methods. A case-controls study, single products only, of 28-42 weeks of gestation; cases were either stillborn and neonatal deaths. Where controls were survivors. Results. There were 57 cases and 114 controls. Significant risk factors were: eclampsia (OR= 4.25, 95%CI 1.76-10.39, p =0.0002), placental detachment (OR = 8.13,95%CL 2.29-31.4, p= 0.00007), general anesthesia (OR= 5.32, 95%CI 1.74-16.51, p=0.0005), respiratory distress syndrome (OR= 23.68, 95%CI 3.31-478 p= 0.00004), mechanic ventilation (OR= 334, 95%CI 42.63-7084, p= 0.000000001), peri-intraventricular hemorrhage (OR = 64.57, 95%CI 8.36-1361, p= 0.0000001), acute renal failure (OR=2613, 95%CI 5.21-177, p=0.0000002) and pulmonary hemorrhage (OR= 8.40, 95%CL 2.71-27.11, p= 0.000006). We observed as protective factors: high maternal educational level (OR=0.110, 95%CI 0.01-0.66, p= 0.02), intrauterine malnutrition (OR= 0.39, 95%CL 0.18-0.84, p= 0.008) and transient tachypnea of the newborn (OR= 0.021, 95%CI0.00-0.15,p= 0.00000001). Conclusions. We found as maternal risk factors: eclampsia; premature placental detachment; general anesthesia, and maternal death, in the newborns they were respiratory distress syndrome, mechanical ventilation and peri-intraventricular hemorrhage. The finding of protection factorsis unteresting.

Antibody responses to Escherichia coli O157 and other lipopolysaccharides in healthy children and adults.

In Mexico, diarrheal disease due to different serotypes of Escherichia coli is highly prevalent, with only sporadic isolation of O157 non-H7 strains. This could be due to exposure to the O157 or related E. coli lipopolysaccharide (LPS), such as O7 or O116, at an early age. By using enzyme-linked immunosorbent assay (ELISA) and Western blotting, the present study analyzed 605 serum samples from Mexican adults and infants without clinical symptoms of disease for the presence of antibodies to these three E. coli LPSs. The bactericidal activities of homologous and heterologous rabbit and human serum samples against O7, O116, and O157 E. coli LPSs were also determined. By using a cutoff point of 0.7, it was found by the ELISAs that 28 of 562 (5%) of the serum samples from adolescents and adults and 2 of 43 (5%) of the serum samples from infants less than 1 year of age reacted with the O157 LPS. By using cutoff points between 0.4 and 0.699, the proportion of serum samples from both age groups that reacted with the O157 LPS increased to 20%. Western blotting analysis of selected serum samples that showed an intermediate response against the O157 LPS by the ELISAs showed that 61 of 88 (69%) reacted with the same LPS. A similar result was observed for maternal milk samples. The bactericidal activities of rabbit serum samples against the O7, O116, and O157 LPSs showed that they were positive for both homologous and heterologous antigens. Similar results were observed with the human serum samples. O157 non-H7 strains were identified in only 10% of the E. coli strains isolated from 263 Mexican children with and without diarrhea over the past 15 years. This absence of O157:H7 strains in Mexico may be associated with the presence of antibodies against O157 or related E. coli LPSs.

Abortion, contraceptive use, and adolescent pregnancy among first-year medical students at a major public university in Mexico City

OBJECTIVE: If properly trained, medical students could become future opinion leaders in health policy and could help the public to understand the consequences of unwanted pregnancies and of abortions. The objective of this study was to analyze the frequency of unwanted pregnancies and induced abortions that had occurred among women who were first-year medical students at a major public university in Mexico City and to compare the experiences of those women with the experiences of the general population of Mexican females aged 15 to 24. METHODS: In 1998 we administered a cross-sectional survey to all the first-year medical students at the National Autonomous University of Mexico, which is the largest university in Latin America. For this study we analyzed 549 surveys completed by female students. RESULTS: Out of the 549 women, 120 of them (22 percent) had been sexually active at some point. Among those 120 sexually active students, 100 of them (83 percent) had used a contraceptive method at some time, and 19 of the 120 (16 percent) had been pregnant. Of those 19 women who had been pregnant, 10 of them had had an illegal induced abortion (in Mexico, abortions are illegal except under a small number of extenuating circumstances). The reported abortion rate among the female medical students, 2 percent, was very low in comparison with the 11 percent rate for women of similar ages in the Mexican general population. CONCLUSIONS: The lower incidence of abortion among the female medical students indicates that when young Mexican women have access to medical information and are highly motivated to avoid unintended pregnancy and abortion, they can do so.

Enteroparasitosis en poblaciones indígenas y mestizas dela Sierra de Nayarit, México / Enteroparasitoses in indigenous and mestizo individuals from the Nayarit mountain range, Mexico

Comparamos las prevalencias de enteropa-rasitosis a partir de 420 individuos, 306 de ellos eran indígenas y 114 eran mestizos, sin dife-renciación de género, y de todos los rangos de edad, de la Sierra de Nayarit. Se hicieron seis viajes al campo a la región durante un año para recoger muestras de materia fecal, algunos individuos proporcionaron solamente una muestra y otros cinco muestras. Las muestras de materia fecal fueron diluidas en una solución de formalina al 10 por ciento en una relación 1:10, para su conservación durante su transporte a la Ciudad de México, donde se procesaron por análisis coproparasitoscópico directo teñido con solución de lugol. Nosotros encontramos 59,8 por ciento de entamoeba histolytica, 22,2 por ciento de Giardia lamblia, 22,2 por ciento de Enterobius vermicularis, 15,4 por ciento de Hymenolepis nana, 2 casos de taeniosis (0,7 por ciento), 21 casos de ascariosis (6,9 por ciento), 2 casos de estrongyloidosis (0,7 por ciento) y 7 casos de trichuriosis (2,3 por ciento) entre la población huichol. En la población mestiza, encontramos 43,9 por ciento de entamoebosis, 14,0 por ciento de giardiosis 9,6 por ciento de hymenolepiosis, 5 casos de ascariosis, 2 de taeniosis, 1 de strongyloidosis y 1 de enterobiosis. Los resultados se analizaron por la prueba del Chi-cuadrada y revelaron diferencias estadísticas significativas entre las dos poblaciones estudiadas