Incidence of hip fractures in Mexico 2006-2019: increasing numbers but decreasing rates.

This study, characterizing the incidence of hip fractures in Mexico, showed not only that the crude number of fractures has increased, but also there has been a decrease in fracture rates. Nonetheless, as the population ages in the coming decades, the current declines rate of could be expected to reverse. PURPOSE: This study is to examine the incidence, rates, and time trends of hip fractures from 2006 to 2019 in Mexico. Additionally, an analysis of the follow-up of the birth cohorts was carried out. METHODS: Hip fractures registered during the period of the study were obtained through the Mexican Social Security Institute (IMSS) national discharge records. The incidence per 100,000 individuals was calculated from the IMSS population at risk. A time trend analysis was conducted using linear regression, and the identification of breakpoints in linear trends. RESULTS: There was an increase of hip fractures for both sexes ≥ 60 years (43% for women and 41%, for men). However, the rates diminished from 167.8/100,000 in 2006 to 138.5 /100,000 in the population 60 and over (1.9% and 0.9% per year in women and men respectively). When the information was analyzed by age groups, hip fracture rates were similar in both sexes but higher in women. The most significant contribution to the total number of fractures is due to the groups ≥ 70 years; people born before 1937 are accounting for the burden of fractures over the total data. In contrast, the younger generations appear to have lower rates. CONCLUSION: Rates of hip fracture have steadily declined in Mexico since 2006; however, with the population aging in the coming decades, current rates declines could be expected to reverse.

How predictive of SARS-CoV-2 infection are clinical characteristics at presentation among individuals with COVID-like symptoms treated at the Mexican Institute of Social Security.

BACKGROUND: The COVID-19 pandemic has progressed rapidly, with the emergence of new virus variants that pose challenges in treating infected individuals. In Mexico, four epidemic waves have been recorded with varying disease severity. To understand the heterogeneity in clinical presentation over time and the sensitivity and specificity of signs and symptoms in identifying COVID-19 cases, an analysis of the changes in the clinical presentation of the disease was conducted. AIM: To analyze the changes in the clinical presentation of COVID-19 among 3.38 million individuals tested for SARS-CoV-2 at the Mexican Social Security Institute (IMSS) from March 2020 to October 2021 and evaluate the predictivity of signs and symptoms in identifying COVID-19 cases. METHODS: A retrospective analysis of clinical presentation patterns of COVID-19 among individuals treated at IMSS was performed, contrasting the signs and symptoms among SARS-CoV-2-positive individuals with those who tested negative for the virus but had respiratory infection symptoms. The sensitivity and specificity of each sign and symptom in identifying SARS-CoV-2 infection were estimated. RESULTS: The set of signs and symptoms reported for COVID-19-suspected patients treated at IMSS were not highly specific for SARS-CoV-2 positivity. The signs and symptoms exhibited variability based on age and epidemic wave. The area under the receiver operating characteristic (ROC) curve was 0.62 when grouping the five main symptoms (headache, dyspnea, fever, arthralgia, and cough). Most of the individual symptoms had ROC values close to 0.5 (16 out of 22 between 0.48 and 0.52), indicating non-specificity. CONCLUSIONS: The results highlight the difficulty in making a clinical diagnosis of COVID-19 due to the lack of specificity of signs and symptoms. The variability of clinical presentation over time and among age groups highlights the need for further research to differentiate whether the changes are due to changes in the virus, who is becoming infected, or the population, particularly with respect to prior infection and vaccination status.

Short-term exposure to PM2.5 and 1.5 million deaths: a time-stratified case-crossover analysis in the Mexico City Metropolitan Area.

BACKGROUND: Satellite-based PM2.5 predictions are being used to advance exposure science and air-pollution epidemiology in developed countries; including emerging evidence about the impacts of PM2.5 on acute health outcomes beyond the cardiovascular and respiratory systems, and the potential modifying effects from individual-level factors in these associations. Research on these topics is lacking in low and middle income countries. We aimed to explore the association between short-term exposure to PM2.5 with broad-category and cause-specific mortality outcomes in the Mexico City Metropolitan Area (MCMA), and potential effect modification by age, sex, and SES characteristics in such associations. METHODS: We used a time-stratified case-crossover study design with 1,479,950 non-accidental deaths from the MCMA for the period of 2004-2019. Daily 1 × 1 km PM2.5 (median = 23.4 µg/m3; IQR = 13.6 µg/m3) estimates from our satellite-based regional model were employed for exposure assessment at the sub-municipality level. Associations between PM2.5 with broad-category (organ-system) and cause-specific mortality outcomes were estimated with distributed lag conditional logistic models. We also fit models stratifying by potential individual-level effect modifiers including; age, sex, and individual SES-related characteristics namely: education, health insurance coverage, and job categories. Odds ratios were converted into percent increase for ease of interpretation. RESULTS: PM2.5 exposure was associated with broad-category mortality outcomes, including all non-accidental, cardiovascular, cerebrovascular, respiratory, and digestive mortality. A 10-µg/m3 PM2.5 higher cumulative exposure over one week (lag06) was associated with higher cause-specific mortality outcomes including hypertensive disease [2.28% (95%CI: 0.26%-4.33%)], acute ischemic heart disease [1.61% (95%CI: 0.59%-2.64%)], other forms of heart disease [2.39% (95%CI: -0.35%-5.20%)], hemorrhagic stroke [3.63% (95%CI: 0.79%-6.55%)], influenza and pneumonia [4.91% (95%CI: 2.84%-7.02%)], chronic respiratory disease [2.49% (95%CI: 0.71%-4.31%)], diseases of the liver [1.85% (95%CI: 0.31%-3.41%)], and renal failure [3.48% (95%CI: 0.79%-6.24%)]. No differences in effect size of associations were observed between age, sex and SES strata. CONCLUSIONS: Exposure to PM2.5 was associated with non-accidental, broad-category and cause-specific mortality outcomes beyond the cardiovascular and respiratory systems, including specific death-causes from the digestive and genitourinary systems, with no indication of effect modification by individual-level characteristics.

Evolution of differences in clinical presentation across epidemic waves among patients with COVID-like-symptoms who received care at the Mexican Social Security Institute.

Background: Timely monitoring of SARS-CoV-2 variants is crucial to effectively managing both prevention and treatment efforts. In this paper, we aim to describe demographic and clinical patterns of individuals with COVID-19-like symptoms during the first three epidemic waves in Mexico to identify changes in those patterns that may reflect differences determined by virus variants. Methods: We conducted a descriptive analysis of a large database containing records for all individuals who sought care at the Mexican Social Security Institute (IMSS) due to COVID-19-like symptoms from March 2020 to October 2021 (4.48 million records). We described the clinical and demographic profile of individuals tested (3.38 million, 32% with PCR and 68% with rapid test) by test result (positives and negatives) and untested, and among those tested, and the changes in those profiles across the first three epidemic waves. Results: Individuals with COVID-19-like symptoms were older in the first wave and younger in the third one (the mean age for those positive was 46.6 in the first wave and 36.1 in the third wave; for negatives and not-tested, the mean age was 41 and 38.5 in the first wave and 34.3 and 33.5 in the third wave). As the pandemic progressed, an increasing number of individuals sought care for suspected COVID-19. The positivity rate decreased over time but remained well over the recommended 5%. The pattern of presenting symptoms changed over time, with some of those symptoms decreasing over time (dyspnea 40.6 to 14.0%, cough 80.4 to 76.2%, fever 77.5 to 65.2%, headache 80.3 to 78.5%), and some increasing (odynophagia 48.7 to 58.5%, rhinorrhea 28.6 to 47.5%, anosmia 11.8 to 23.2%, dysgeusia 11.2 to 23.2%). Conclusion: During epidemic surges, the general consensus was that any individual presenting with respiratory symptoms was a suspected COVID-19 case. However, symptoms and signs are dynamic, with clinical patterns changing not only with the evolution of the virus but also with demographic changes in the affected population. A better understanding of these changing patterns is needed to improve preparedness for future surges and pandemics.

Daily exposure to PM2.5 and 1.5 million deaths: A time-stratified case-crossover analysis in the Mexico City Metropolitan Area.

Background: Satellite-based PM2.5 predictions are being used to advance exposure science and air-pollution epidemiology in developed countries; including emerging evidence about the impacts of PM2.5 on acute health outcomes beyond the cardiovascular and respiratory systems, and the potential modifying effects from individual-level factors in these associations. Research on these topics is lacking in Latin America. Methods: We used a time-stratified case-crossover study design with 1,479,950 non-accidental deaths from Mexico City Metropolitan Area for the period of 2004-2019. Daily 1×1 km PM2.5 (median=23.4 µg/m3; IQR=13.6 µg/m3) estimates from our satellite-based regional model were employed for exposure assessment at the sub-municipality level. Associations between PM2.5 with broad-category (organ-system) and cause-specific mortality outcomes were estimated with distributed lag conditional logistic models. We also fit models stratifying by potential individual-level effect modifiers including; age, sex, and individual SES-related characteristics namely: education, health insurance coverage, and job categories. Results: PM2.5 exposure was associated with higher total non-accidental, cardiovascular, cerebrovascular, respiratory, and digestive mortality. A 10-µg/m3 PM2.5 higher cumulative exposure over one week (lag06) was associated with higher cause-specific mortality outcomes including hypertensive disease [2.28% (95%CI: 0.26%-4.33%)], acute ischemic heart disease [1.61% (95%CI: 0.59%-2.64%)], other forms of heart disease [2.39% (95%CI: -0.35%-5.20%)], hemorrhagic stroke [3.63% (95%CI: 0.79%-6.55%)], influenza and pneumonia [4.91% (95%CI: 2.84%-7.02%)], chronic respiratory disease [2.49% (95%CI: 0.71%-4.31%)], diseases of the liver [1.85% (95%CI: 0.31%-3.41%)], and renal failure [3.48% (95%CI: 0.79%-6.24%)]. No differences in effect size of associations were observed between SES strata. Conclusions: Exposure to PM2.5 was associated with mortality outcomes beyond the cardiovascular and respiratory systems, including specific death-causes from the digestive and genitourinary systems, with no indications of effect modification by individual SES-related characteristics.

Comparative epidemiology of five waves of COVID-19 in Mexico, March 2020-August 2022.

BACKGROUND: The Mexican Institute of Social Security (IMSS) is the largest health care provider in Mexico, covering about 48% of the Mexican population. In this report, we describe the epidemiological patterns related to confirmed cases, hospitalizations, intubations, and in-hospital mortality due to COVID-19 and associated factors, during five epidemic waves recorded in the IMSS surveillance system. METHODS: We analyzed COVID-19 laboratory-confirmed cases from the Online Epidemiological Surveillance System (SINOLAVE) from March 29th, 2020, to August 27th, 2022. We constructed weekly epidemic curves describing temporal patterns of confirmed cases and hospitalizations by age, gender, and wave. We also estimated hospitalization, intubation, and hospital case fatality rates. The mean days of in-hospital stay and hospital admission delay were calculated across five pandemic waves. Logistic regression models were employed to assess the association between demographic factors, comorbidities, wave, and vaccination and the risk of severe disease and in-hospital death. RESULTS: A total of 3,396,375 laboratory-confirmed COVID-19 cases were recorded across the five waves. The introduction of rapid antigen testing at the end of 2020 increased detection and modified epidemiological estimates. Overall, 11% (95% CI 10.9, 11.1) of confirmed cases were hospitalized, 20.6% (95% CI 20.5, 20.7) of the hospitalized cases were intubated, and the hospital case fatality rate was 45.1% (95% CI 44.9, 45.3). The mean in-hospital stay was 9.11 days, and patients were admitted on average 5.07 days after symptoms onset. The most recent waves dominated by the Omicron variant had the highest incidence. Hospitalization, intubation, and mean hospitalization days decreased during subsequent waves. The in-hospital case fatality rate fluctuated across waves, reaching its highest value during the second wave in winter 2020. A notable decrease in hospitalization was observed primarily among individuals ≥ 60 years. The risk of severe disease and death was positively associated with comorbidities, age, and male gender; and declined with later waves and vaccination status. CONCLUSION: During the five pandemic waves, we observed an increase in the number of cases and a reduction in severity metrics. During the first three waves, the high in-hospital fatality rate was associated with hospitalization practices for critical patients with comorbidities.

Fracture incidence in children and adolescents 0-19 years old in Mexico: a 12-year cross-sectional analysis.

The objective was to know the behavior of fractures in Mexican children and adolescents. According to our study, fractures in Mexican male children and adolescents seem to be decreasing; however, we still need more national studies to know the possible causes of these fractures. PURPOSE: To describe the trends of fractures in Mexican children and adolescents across a 12-year period (2007 to 2019), and to analyze if these trends have changed over time between sexes and age groups. METHODS: We identified all fracture cases registered in children and adolescents (0 to 19 years) at the emergency rooms and surgical departments of the Mexican Institute of Social Security between January 2007 and December 2019. We used ICD-10 to classify the fractures. The population was divided into two age groups: children (0 to 9 years) and adolescents (10 to 19 years). Additional information regarding sex and age was gathered up as well. We calculated annual incidence; incidence rates are presented per 10,000 population at risk. Changes in fracture trends were calculated using the average annual percentage change (AAPC). RESULTS: Over 12 years, 1,400,443 fractures were registered. The most frequent site of fracture was forearm in 37.1% followed by shoulder (18.1%). The overall rates of fractures have remained similar over 12 years (86.5, IQR 81.0-94.2); however, a significant decrease in fractures was observed the last 3 years (2017-2019). According to the AAPC, only in men, in both age groups, a significant decrease in fractures was observed. CONCLUSION: This is the first study in Mexico to follow the behavior of fractures in the pediatric population over 12 years. Fractures seem to be decreasing in children and adolescents. An epidemiological follow-up of childhood fractures is necessary to understand the causes of fractures to generate better prevention and treatment strategies.

[Integrated Care Protocol: Hypertension]. / Protocolo de Atención Integral: hipertensión arterial sistémica.

Background: Hypertension is the most common cardiovascular risk factor that is responsible for complications such as cerebrovascular events, heart failure, acute myocardial infarction, kidney failure, arrhythmias and blindness. About 30% of the adult population older than 20 years is a carrier. 40% of carriers are unaware of suffering from it since its onset is generally asymptomatic. Unfortunately, of those who are already known to be hypertensive, only half take drug treatment and of these, only half achieve control figures (<14/90 mmHg). For several decades it has not been possible to forcefully modify the natural history of this disease despite the advancement of therapeutic drugs. The Mexican Institute of Social Security launches the initiative of the Integrated Care Protocols (PAI) of the main diseases. This protocol shows how the three levels of medical care are concatenated, the role of each of the members of the multidisciplinary team for medical care, including: doctor, nurse, social work, psychologist, nutritionist, among others and, to patient sharing. The main changes in diagnostic criteria, in-office and out-of-office blood pressure measurement, drug therapy (monotherapy, dual therapy and triple therapy) and non-drug therapy, and follow-up are presented. The diagnostic-therapeutic approach using algorithm as well as the diagnostic approach to secondary hypertension and special forms of hypertension such as in pregnancy, hypertensive crisis, hypertension in the elderly, ischemic or nephropathy patients.

Introducción: la hipertensión arterial sistémica (HAS) es el factor de riesgo cardiovascular más común y es responsable de complicaciones como evento cerebrovascular, insuficiencia cardiaca, infarto agudo de miocardio, insuficiencia renal, arritmias y ceguera. Alrededor del 30% de la población adulta mayor de 20 años es portadora. El 40% de los portadores ignoran padecerla ya que su inicio generalmente es asintomático. Desafortunadamente de los que ya se saben hipertensos solo la mitad toma tratamiento farmacológico y de estos, tan solo la mitad logra cifras de control (< 140/90 mmHg). Durante varias décadas no se ha logrado de forma contundente modificar la historia natural de esta enfermedad pese al avance fármaco terapéutico. El Instituto Mexicano del Seguro Social, lanza la iniciativa de los Protocolos de Atención Integral (PAI) de las principales enfermedades. En el presente protocolo se muestra cómo se concatenan los tres niveles de atención médica, el papel de cada uno de los integrantes del equipo multidisciplinario para la atención médica, incluyendo: médico, enfermera, trabajo social, psicólogo, nutricionista, entre otros y, la coparticipación del paciente. Se presentan los principales cambios en criterios diagnósticos, medición de la presión arterial dentro y fuera de consultorio, terapéutica farmacológica (monoterapia, terapia dual y terapia triple), no farmacológica y seguimiento. El Abordaje diagnóstico-terapéutico usando algoritmos, así como también el abordaje diagnóstico de la hipertensión secundaria y formas especiales de hipertensión tales como en el embarazo, crisis hipertensivas, hipertensión en el adulto mayor, pacientes isquémicos o con nefropatía.

Perception and Knowledge of Mercury by Occupationally Exposed Health Care Personnel.

Thermometers and baumanometers frequently contain mercury, a toxic heavy metal. Inadequate management of this substance can constitute an occupational hazard by exposing health care professionals to health risks including memory loss, psychosomatic symptoms, fatigue, and other signs of cognitive dysfunction as reported in several studies. PURPOSE: To assess Mexico's health care professionals' health and mercury-related knowledge and risk perception and to explore the measurement properties of a questionnaire assessing that level of knowledge. MATERIALS AND METHODS: Mixed methodology. A quantitative, cross-sectional study was conducted to measure health care professionals' knowledge of mercury and to validate an instrument using a Rasch analysis in 160 professionals. A qualitative study involving in-depth interviews was conducted to identify participants' risk perception for mercury exposure. RESULTS: The total knowledge of mercury was 19.0 ± 2.0 on a scale of 0 to 28 points. The scores for medical specialists were significantly (P < .001) higher, ranging between 20.0 ± 2.05 and 23.0 ± 1.63. In general, the level of risk perception for mercury exposure was low. The questionnaire presented a reasonable fit to the Rasch model (good item fit with a Bonferroni-adjusted P = .000714). The response categories of three items were collapsed, and two pairs of items were bundled into two super items. CONCLUSION: The levels of the knowledge of the health and safety risks and risk perception for mercury exposure in the Mexican health care professionals evaluated were low. Health care professionals should receive comprehensive training in the safe use and health risks of mercury.

[Coinfections by SARS-CoV-2 and other respiratory viruses and their clinical outcome]. / Coinfecciones por SARS-CoV-2 y otros virus respiratorios y su desenlace clínico.

Background: SARS-CoV-2 is a coronavirus described for the first time in China, in December 2019. This virus can cause a disease with a very variable spectrum that ranges from asymptomatic cases to deaths. The most severe cases are normally associated with comorbidities and with the age of the patient. However, there are patients who are not part of these risk groups and develop severe cases. Objetive: To determine the association between coinfections by SARS-CoV-2 and other respiratory viruses and their clincal outcome. Material and methods: RT-qPCR was performed to determine the presence of 16 respiratory viruses in 103 confirmed COVID-19 cases. Demographic and comorbid data were collected, and statistical analyzes were performed to determine associations with severity. Results: Of the 103 analyzed cases, 14 (13.6%) presented a coinfection, of these, 92% did not require hospitalization, even in those cases in which the patient presented advanced age and some comorbidities. Conclusions: These results suggest that coinfection of SARS-CoV-2 and other respiratory viruses is not related to a more severe form of COVID-19 and, in some cases, depending on the virus involved, it could even lead to a better prognosis. These findings lay the foundations for the development of new studies that could determine the biological mechanism of this phenomenon.

Introducción: el SARS-CoV-2 es un coronavirus que fue descrito por primera vez en diciembre de 2019 en Wuhan, China. Este virus causa una enfermedad que varía en un espectro de severidad que va desde casos asintomáticos hasta defunciones. Los casos más severos se asocian normalmente con algunas comorbilidades y con la edad del paciente. Sin embargo, existen pacientes que no son parte de estos grupos de riesgo y aun así desarrollan casos graves. Objetivo: determinar la asociación entre las coinfecciones por SARS-CoV-2 y otros virus respiratorios y su desenlace clínico. Material y métodos: se realizó RT-qPCR para determinar la presencia de 16 virus respiratorios en 103 casos confirmados de COVID-19. Se recolectaron datos demográficos y de comorbilidades, y se realizaron análisis estadísticos para determinar asociaciones con gravedad. Resultados: el 13.6% de los casos (14/103) presentaron alguna coinfección, de estos, el 92% nunca requirió ingreso hospitalario, aun en aquellos casos en los que el paciente presentara comorbilidades y edad avanzada. Conclusiones: estos resultados sugieren que la coinfección no está relacionada con un COVID-19 más grave y que, dependiendo del virus involucrado, incluso podría conducir a un mejor pronóstico. Estos hallazgos sientan las bases para nuevos estudios dirigidos a determinar el mecanismo biológico por el cual ocurre este fenómeno y a proponer las estrategias correspondientes para limitar la progresión a casos severos de COVID-19.

Coinfecciones por SARS-CoV-2 y otros virus respiratorios y su desenlace clínico / Coinfections by SARS-CoV-2 and other respiratory viruses and their clinical outcome

Introducción: el SARS-CoV-2 es un coronavirus que fue descrito por primera vez en diciembre de 2019 en Wuhan, China. Este virus causa una enfermedad que varía en un espectro de severidad que va desde casos asintomáticos hasta defunciones. Los casos más severos se asocian normalmente con algunas comorbilidades y con la edad del paciente. Sin embargo, existen pacientes que no son parte de estos grupos de riesgo y aun así desarrollan casos graves. Objetivo: determinar la asociación entre las coinfecciones por SARS-CoV-2 y otros virus respiratorios y su desenlace clínico. Material y métodos: se realizó RT-qPCR para determinar la presencia de 16 virus respiratorios en 103 casos confirmados de COVID-19. Se recolectaron datos demográficos y de comorbilidades, y se realizaron análisis estadísticos para determinar asociaciones con gravedad. Resultados: el 13.6% de los casos (14/103) presentaron alguna coinfección, de estos, el 92% nunca requirió ingreso hospitalario, aun en aquellos casos en los que el paciente presentara comorbilidades y edad avanzada. Conclusiones: estos resultados sugieren que la coinfección no está relacionada con un COVID-19 más grave y que, dependiendo del virus involucrado, incluso podría conducir a un mejor pronóstico. Estos hallazgos sientan las bases para nuevos estudios dirigidos a determinar el mecanismo biológico por el cual ocurre este fenómeno y a proponer las estrategias correspondientes para limitar la progresión a casos severos de COVID-19.

Background: SARS-CoV-2 is a coronavirus described for the first time in China, in December 2019. This virus can cause a disease with a very variable spectrum that ranges from asymptomatic cases to deaths. The most severe cases are normally associated with comorbidities and with the age of the patient. However, there are patients who are not part of these risk groups and develop severe cases. Objetive: To determine the association between coinfections by SARS-CoV-2 and other respiratory viruses and their clincal outcome. Material and methods: RT-qPCR was performed to determine the presence of 16 respiratory viruses in 103 confirmed COVID-19 cases. Demographic and comorbid data were collected, and statistical analyzes were performed to determine associations with severity. Results: Of the 103 analyzed cases, 14 (13.6%) presented a coinfection, of these, 92% did not require hospitalization, even in those cases in which the patient presented advanced age and some comorbidities. Conclusions: These results suggest that coinfection of SARS-CoV-2 and other respiratory viruses is not related to a more severe form of COVID-19 and, in some cases, depending on the virus involved, it could even lead to a better prognosis. These findings lay the foundations for the development of new studies that could determine the biological mechanism of this phenomenon.

Comportamiento epidemiológico de SARS-CoV-2 en población trabajadora afiliada al Instituto Mexicano del Seguro Social / SARS-CoV-2 epidemic behavior in worker population affiliated to the Mexican Social Security Institute

Resumen: Objetivo: Describir el comportamiento de la epidemia de SARS-CoV-2 entre los trabajadores afiliados al Instituto Mexicano del Seguro Social (IMSS). Material y métodos: Se analizaron las incapacidades temporales para el trabajo por enfermedades respiratorias (ITT-ER), las hospitalizaciones y defunciones asociadas durante el periodo del 1 marzo al 31 diciembre 2020. Se estimó la tasa de ataque (TA) por SARS-CoV-2, así como los riesgos relativos (RR) de ITT-ER, hospitalización y defunción. Resultados: De los trabajadores afiliados al IMSS, 8.8% (n=1 730 334) recibió al menos una ITT-ER. La TA fue mayor en mujeres y en ambos sexos fue menor en el grupo de >60 años. Los RR de hospitalización y defunción fueron mayores en hombres y aumentaron con la edad. Comparado con las ITT-ER de 2015-2019, Durango, Tamaulipas y Nuevo León tuvieron un RR mayor de ITT-ER que el resto del país. Conclusiones: La epidemia de SARS-CoV-2 tuvo repercusiones importantes en los trabajadores afiliados al IMSS; se observó un exceso de ITT-ER de 4.6 veces respecto a la frecuencia esperada y cerca de un millón de casos de SARS-CoV-2. Los datos sugieren que el sistema de ITT-ER puede ser utilizado como elemento adicional para la vigilancia epidemiológica de enfermedades emergentes.

Abstract: Objective: To describe the behavior of SARS-CoV-2 epidemic among workers affiliated to the Mexican Social Security Institute. Materials and methods: We analyzed Short Term Disability Claims due to Respiratory Diseases (RD-STDC), associated hospitalizations and deaths (March 1 - December 31, 2020). We estimated the attack rate (AR) for SARS-CoV-2, and relative risks (RR) of TWD-RD, hospitalization and deaths. Results: 1 730 334 workers received at least one RD-STDC. AR was higher in women and in both sexes it was lower in >60 years old. RR of hospitalization and death were higher in men and increased with age. Compared with RD-STDC of 2015-2019, the states of Durango, Tamaulipas and Nuevo Leon had a higher RR of RD-STDC than the rest of the country. Conclusions: The SARS-CoV-2 epidemic impacted IMSS-affiliated workers significantly. We observed a 4.6 fold excess in RD-STDC compared to the expected frequency and nearly 1 million SARS-CoV-2 cases in this population. Our data suggest that the RD-STDC system can be used as an additional resource for epidemiological surveillance of emerging diseases.

Effect of phthalates exposure during perinatal period on hormonal profile in Mexican males during their first months of life.

Phthalates affect development of male reproductive system acting as an antiandrogenic agents. We sought to explore if perinatal exposure to phthalates could alter male hormone levels in humans during the first months of life. A cohort of 83 pregnant women and their male infants were studied. Five phthalate metabolites were measured in the mother's urine during the first, second, and third trimesters of pregnancy and during the first, third, and sixth months of life in the infants. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and inhibin B were analyzed. Association between phthalate exposure and hormone variation was assessed using regression models for longitudinal data. Mono-butyl phthalate reduced FSH concentration (ß = -0.0012 international units [IU]/L, p < 0.01), mono-ethylhexyl phthalate reduced inhibin B (ß = -0.0094 pg/mL, p = 0.02), monoethyl phthalate reduced testosterone (ß = -0.0071 ng/L, p = 0.07), mono-ocytl phthalate reduced LH (ß = -0.0041 IU/L, p = 0.13). No effects were observed for exposure to mono-methyl phthalate. Our results are consistent with the findings in animal and human studies. Special precaution should be taken when measuring phthalate exposure in susceptible populations such as pregnant women and infants.

Infection and death by COVID-19 in a cohort of healthcare workers in Mexico.

OBJECTIVE: This study aimed to estimate the risk of SARS-Cov2 infection and severe COVID-19 among healthcare workers from a major social security system. METHODS: This study actively followed a cohort of social security workers from March to December 2020 to determine the number of laboratory-confirmed symptomatic cases, asymptomatic associated contacts and COVID-19-associated hospitalizations and deaths. Workers were classified into those providing direct care to infected patients (COVID teams), other active healthcare workers (OAHCW), and workers under home protection (HPW). The number of cases and rates were also estimated by job category. RESULTS: Among a total of 542 381 workers, 41 461 were granted stay-at-home protection due to advanced age or comorbidities. Among the 500 920 total active workers, 85 477 and 283 884 were classified into COVID teams and OAHCW, respectively. Infection rates for COVID teams, OAHCW, and HPW were 20.1% [95% confidence interval (CI) 19.8-20.4], 13.7% (95% CI 15.0-15.3), and 12.2% (95% CI 11.8-12.5), respectively. The risk of hospitalization was higher among HPW. COVID teams had lower mortality rate per 10 000 workers compared to HPW (5.0, 95% CI 4.0-7.0 versus 18.1, 95% CI 14.0-23.0). Compared to administrative workers, ambulance personnel (RR 1.20; 95% CI 1.09-1.32), social workers (RR 1.16; 95% CI 1.08-1.24), patient transporters (RR 1.15; 95% CI 1.09-1.22) and nurses (RR 1.13; 95% CI 1.10-1.15) had a higher risk of infection after adjusting for age and gender. Crude differences in mortality rates were observed according to job category, which could be explained by differences in age, sex, and comorbidity distribution. Diabetes, obesity, hypertension, hemolytic anemia, and HIV were associated with increased fatality rates. CONCLUSIONS: COVID team workers had higher infection rates compared to the total population of active workers and HPW. Doctors had lower risk of infection than respiratory therapists, nurses, and patient transporters, among whom interventions should be reconsidered to reduce risks. The presence of comorbidities, such as diabetes, obesity, arterial hypertension, hemolytic anemia, and HIV, increased the likelihood of complications caused by COVID-19, culminating in a poor prognosis.

Phthalates exposure during pregnancy a study in a Mexican cohort.

A prospective cohort study was conducted to measure the concentration levels of three primary phthalate metabolites (MBP, MEHP, MEP) during pregnancy in a group of women from the State of Mexico. The urinary concentration levels of the three phthalate primary metabolites were measured by gas chromatography mass spectrometry during the first, second and third trimesters of pregnancy. The geometric mean and 95 % CI for MBP was 20.38 µg/mL (15.35-27.09); for MEHP 13.43 µg/mL (8.93-20.20), and MEP 52.47 µg/mL (39.88-69.04) adjusted to one g of creatinine. No significant trends were observed among the studied metabolites during the pregnancy period. MBP was higher in less educated women, while women who resided in industrialized zones showed higher levels of MEHP and MEP than women from non-industrialized zones. Consumption of plastic bottled beverages was associated with MBP and MEHP phthalate exposure. Women who used non-registered brands of plastic food containers for storage or for microwave oven use showed the highest levels of MBP and MEP phthalates. The pregnant women in our study were exposed to the three studied primary phthalate metabolites, and this could present a risk to their newborns. To better integrate public health policies, major exploration of potential exposure sources and effects at the regional level is required.

SARS-CoV-2 IgG Antibodies Seroprevalence and Sera Neutralizing Activity in MEXICO: A National Cross-Sectional Study during 2020.

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico's first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.

Pregnant Women Infected with Zika Virus Show Higher Viral Load and Immunoregulatory Cytokines Profile with CXCL10 Increase.

BACKGROUND: Zika virus (ZIKV) infection during pregnancy usually shows only mild symptoms and is frequently subclinical. However, it can be vertically transmitted to the fetus, causing microcephaly and other congenital defects. During pregnancy, the immune environment modifications can alter the response to viruses in general and ZIKV in particular. OBJECTIVE: To describe the role of pregnancy in the systemic pro- and anti-inflammatory response during symptomatic ZIKV infection. MATERIALS AND METHODS: A multiplex assay was used to measure 25 cytokines, chemokines, and receptors in 110 serum samples from pregnant and nonpregnant women with and without ZIKV infection with and without symptoms. Samples were collected through an epidemiological surveillance system. RESULTS: Samples from pregnant women with ZIKV infection showed a higher viral load but had similar profiles of inflammatory markers as compared with nonpregnant infected women, except for CXCL10 that was higher in infected pregnant women. Notably, the presence of ZIKV in pregnancy favored a regulatory profile by significantly increasing anti-inflammatory cytokines such as interleukin (IL)-10, receptors IL-1RA, and IL-2R, but only those pro-inflammatory cytokines such as IL-6, interferon (IFN)-α, IFN-γ and IL-17 that are essential for the antiviral response. Interestingly, there were no differences between symptomatic and weakly symptomatic ZIKV-infected groups. CONCLUSION: Our results revealed a systemic anti-inflammatory cytokine and chemokine profile that could participate in the control of the virus. The anti-inflammatory response in pregnant women infected with ZIKA was characterized by high CXCL10, a cytokine that has been correlated with congenital malformations.

Comportamiento epidemiológico de SARS-CoV-2 en población trabajadora afiliada al Instituto Mexicano del Seguro Social.

Objetivo. Describir el comportamiento de la epidemia de SARS-CoV-2 entre los trabajadores afiliados al Instituto Mexicano del Seguro Social (IMSS). Material y métodos. Se analizaron las incapacidades temporales para el trabajo por enfermedades respiratorias (ITT-ER), las hospitalizaciones y defunciones asociadas durante el periodo del 1 marzo al 31 diciembre 2020. Se estimó la tasa de ataque (TA) por SARS-CoV-2, así como los riesgos relativos (RR) de ITT-ER, hos-pitalización y defunción. Resultados. De los trabajadores afiliados al IMSS, 8.8% (n=1 730 334) recibió al menos una ITT-ER. La TA fue mayor en mujeres y en ambos sexos fue menor en el grupo de >60 años. Los RR de hospitalización y defunción fueron mayores en hombres y aumentaron con la edad. Comparado con las ITT-ER de 2015-2019, Durango, Tamaulipas y Nuevo León tuvieron un RR mayor de ITT-ER que el resto del país. Conclusiones. La epidemia de SARS-CoV-2 tuvo repercusiones importantes en los trabajadores afiliados al IMSS; se observó un exceso de ITT-ER de 4.6 veces respecto a la frecuencia esperada y cerca de un millón de casos de SARS-CoV-2. Los datos sugieren que el sistema de ITT-ER puede ser utilizado como elemento adicional para la vigilancia epidemiológica de enfermedades emergentes.

Hypertension, Diabetes and Obesity, Major Risk Factors for Death in Patients with COVID-19 in Mexico.

BACKGROUND: Mexico has reported high death and case fatality rates due to COVID-19. Several comorbidities have been related to mortality in COVID-19, as hypertension, diabetes, coronary heart disease, chronic obstructive lung disease and chronic kidney disease. AIMS: To describe the main clinical characteristics of COVID-19 in the major social security institution in Mexico, as well as the contribution of chronic comorbidities and the population attributable fraction related to them. METHODS: Data for all patients with a positive test for SARS-CoV-2 in the institutional database was included for analysis. Demographic information, the presence of pneumonia and whether the patient was hospitalized or treated at home as an outpatient as well as comorbidities were analyzed. Case fatality rate was estimated for different groups. Odds ratios with 95% confidence intervals from a logistic regression model were estimated, as well as the population attributable fraction. RESULTS: By November 13, 2020, 323,671 subjects with COVID-19 infection have been identified. Case fatality rate is higher in males (20.2%), than in females (13.0%), and increases with age. Case fatality rate increased with the presence of obesity, hypertension and/or diabetes. Age and sex were major independent risk factors for mortality, as well as the presence of pneumonia, diabetes, hypertension, obesity, immunosuppression, and end-stage kidney disease. The population attributable fraction due to obesity in outpatients was 16.8%. CONCLUSIONS: Major cardiovascular risk factors and other comorbidities increase the risk of dying in patients with COVID-19. Identification of populations with high fatality in COVID-19, provides insight to deal with this pandemic by health services in Mexico.