Ten-Year Single-Center Study Examining Patient Survival after Commencing Long-Term Peritoneal Dialysis.

In patients with end-stage kidney disease (ESKD), peritoneal dialysis (PD) is increasingly being adopted in developing nations due to its cost-effectiveness and advantages as a home-based treatment. However, the survival outcomes of chronic PD patients in Mexico, where the burden of ESKD is high, remain poorly understood. This study aimed to assess the survival experience of long-term PD patients and evaluate its determinants. A single-center cohort study collected clinical and epidemiological data for long-term PD initiations between February 2013 and January 2023. The analysis, which utilized Kaplan-Meier and Cox proportional hazard regression methods, included data from 370 patients. The overall mortality rate was 4.7 per 1000 person-months, with a significant decrease in survival rates observed between months 24 and 36 post-PD initiation. Older age at PD initiation and the use of continuous ambulatory peritoneal dialysis, as compared to the automated modality, were associated with an increased risk of mortality. The study provides valuable insights into the survival outcomes of chronic PD patients in Mexico and suggests the need to optimize treatment strategies to enhance long-term prognoses for patients with ESKD. Further research is needed to better understand the factors influencing survival in this population.

Interactions between the principal risk factors for reduction of the eGFR in unvaccinated COVID­19 survivors: Normal pre-COVID­19 eGFR, not having diabetes and being hospitalized.

There are contradictory results regarding changes in estimated glomerular filtration rate (eGFR) in coronavirus disease 2019 (COVID-19) survivors. An analysis of eGFR changes and clinical characteristics associated with those changes was conducted among COVID-19 survivors. eGFR values were compared at different time points (before and 4-, 8- and 12-months after COVID-19 infection). A multivariate generalized linear mixed model (GENLINMIXED procedure) with a binary logistic regression link was used to determine factors associated with eGFR reduction of ≥10 ml/min/1.73 m2. Being hospitalized (RR=2.90, 95% CI=1.10-7.68, P=0.032), treated with Ivermectin (RR=14.02, 95% CI=4.11-47.80, P<0.001) or anticoagulants (RR=6.51, 95% CI=2.69-15.73, P<0.001) are risk factors for a reduced eGFR. Having a low eGFR (<90 ml/min/1.73 m2) before COVID-19 infection, having B-positive blood type, diabetes, taking vitamin C during the acute phase of COVID-19 or suffering from chronic COVID-19 symptoms, were identified as protective factors. Analysis involving a two-way interaction (A x B, where A and B are factors) demonstrated that the combination of patients with a normal eGFR value before COVID-19 infection without diabetes (RR=58.60, 95% CI=11.62-295.38, P<0.001), or a normal eGFR value with being hospitalized for COVID-19 (RR=38.07, 95% CI=8.68-167.00, P<0.001), increased the probability of a reduced eGFR. The changes in eGFR in COVID-19 survivors varied depending on patient characteristics. Furthermore, the principal risk factors for post-COVID-19 eGFR reduction were analyzed in separate models.

Association between Vaccination Status for COVID-19 and the Risk of Severe Symptoms during the Endemic Phase of the Disease.

The global health emergency caused by COVID-19 concluded in May 2023, marking the beginning of an endemic phase. This study aimed to evaluate the association between vaccination status and other patient characteristics and the risk of severe disease during this new endemic period. A nationwide cohort study was conducted in Mexico, where we analyzed data from 646 adults who had received positive confirmation of COVID-19 through PCR testing from May to August 2023. The overall risk of severe symptoms in the study sample was 5.3%. The average time elapsed from the last vaccine shot to symptom onset was over six months in all the immunized groups (1, 2 or 3 vaccine doses). Compared to unvaccinated patients, those with three vaccine doses showed an elevated risk of severe symptoms. Advancing age and various chronic comorbidities (specifically cardiovascular, kidney, and obstructive pulmonary conditions) were associated with a heightened risk of severe COVID-19 manifestations. These findings underscore the ongoing seriousness of COVID-19, even in an endemic phase, underscoring the urgent need for tailored interventions aimed at high-risk patients.

Survival Analysis and Contributing Factors among PCR-Confirmed Adult Inpatients during the Endemic Phase of COVID-19.

In May 2023, the global health emergency status of COVID-19 concluded, marking the onset of an endemic era. This study assessed survival rates among PCR-confirmed adult inpatients during this phase and determined contributing factors. Employing a survival analysis approach, this investigation utilized a nationwide Mexican cohort encompassing 152 adult inpatients. Survival rates were computed using the Kaplan-Meier method, and a proportional Cox model identified mortality risk factors. Survival rates remained above 65% on day 14 after admission. Vaccination status, including the number of doses administered, was not significantly associated with fatal outcomes. Chronic kidney disease or a history of immunosuppression (due to any cause) increased mortality risk. Our findings underscore the persistent severity of COVID-19 beyond the global health emergency, emphasizing the necessity for tailored interventions for vulnerable patients.

Assessing the Influence of COVID-19 Vaccination Coverage on Excess Mortality across 178 Countries: A Cross-Sectional Study.

The COVID-19 pandemic has had a devastating impact on global health, necessitating urgent and effective strategies to mitigate its consequences. Vaccination programs have been implemented worldwide to combat virus transmission and reduce the disease burden. This study aimed to investigate the relationship between COVID-19 vaccination coverage and all-cause excess mortality in 178 nations during the first two years of the pandemic. Multiple regression analysis, after adjusting for life expectancy at birth, confirmed a significant association between higher vaccination coverage and lower all-cause mortality rates (ß = -106.8, 95% CI -175.4 to -38.2, p = 0.002). These findings underscore the importance of vaccination campaigns in reducing overall mortality during the COVID-19 pandemic. Evidence-based decision making and resource allocation can benefit from this information, facilitating the optimization of vaccination strategies for maximal impact on mortality reduction. Further research and continuous monitoring are crucial to understanding the long-term effects of vaccination coverage on population health in the ongoing pandemic.

Assessing the relationship between energy-related methane emissions and the burden of cardiovascular diseases: a cross-sectional study of 73 countries.

The energy industry significantly contributes to anthropogenic methane emissions, which add to global warming and have been linked to an increased risk of cardiovascular diseases (CVD). This study aims to evaluate the relationship between energy-related methane emissions and the burden of CVD, measured in disability-adjusted life years (DALYs), in 2019. We conducted a cross-sectional analysis of datasets from 73 countries across all continents. The analyzed datasets included information from 2019 on environmental energy-related methane emissions, burden of DALYs due to CVD. The age-standardized prevalence of obesity in adults and life expectancy at birth were retrieved. The relationship between the variables of interest was evaluated using multiple linear regression models. In the multiple model, we observed a positive linear association between methane emissions and the log-transformed count of DALYs related to CVD. Specifically, for each unit increase in energy-related methane emissions, the burden of CVD increased by 0.06% (95% CI 0.03-0.09%, p < 0.001). The study suggests that reducing methane emissions from the energy industry could improve public health for those at risk of CVD. Policymakers can use these findings to develop strategies to reduce methane emissions and protect public health.

Urinary epidermal growth factor in kidney disease: A systematic review / Factor de crecimiento epidérmico urinario en la enfermedad renal: una revisión sistemática

Urinary epidermal growth factor (uEGF) is primarily produced by the kidney, and alterations of it have been associated with several kidney diseases. The aim of this review was to describe uEGF levels in presence or progression of kidney diseases. We conducted a systematic review of observational studies with uEGF determination, patients with acute kidney injury, chronic kidney disease, primary or secondary nephropathy, or renal cancer were included. Studies were searched in Medline, Google Scholar, Science Direct, and EBSCO up to August 2, 2021. Participants and measurements characteristics from which uEGF were determined as the specificity, sensitivity, and the area under the ROC curve, whenever available, were gathered. 53 studies were included, the most frequent kidney diseases studied were acute kidney injury, chronic kidney disease, and diabetic nephropathy. In most studies, uEGF levels were lower in cases than in controls. Studies showed that uEGF levels can predict presence or progression of acute kidney injury, chronic kidney disease, and nephropathy. Heterogeneity in the reported uEGF values can be attributed to the different techniques, sampling, and ways of reporting uEGF values. Although uEGF values are lower in patients with almost all kidney diseases and their progression, uEGF evaluation methods should be standardised to be used as a biomarker in clinical practice. (AU)

El factor de crecimiento epidérmico urinario (uEGF) es producido principalmente por el riñón, y sus alteraciones se han asociado con varias enfermedades renales. El objetivo de esta revisión fue describir los niveles de uEGF en presencia o progresión de enfermedades renales. Realizamos una revisión sistemática de estudios observacionales con determinación de uEGF en la que se incluyeron pacientes con insuficiencia renal aguda, enfermedad renal crónica, nefropatía primaria o secundaria, o cáncer renal. Se realizaron búsquedas de estudios en Medline, Google Scholar, Science Direct y EBSCO hasta el 2 de agosto de 2021. Se extrajeron las características de los participantes y de las mediciones del uEGF, así como la especificidad, la sensibilidad y el área bajo la curva ROC, siempre que estuvieran disponibles. Se incluyeron 53 estudios, y las enfermedades renales más frecuentes estudiadas fueron la insuficiencia renal aguda, la enfermedad renal crónica y la nefropatía diabética. En la mayoría de los estudios los niveles de uEGF fueron más bajos en los casos que en los controles. Los estudios demostraron que los niveles de uEGF pueden predecir la presencia o la progresión de la lesión renal aguda, la enfermedad renal crónica y la nefropatía. La heterogeneidad en los valores de uEGF informados se puede atribuir a las diferentes técnicas, muestreo y formas de informar los valores de uEGF. Aunque los valores de uEGF son más bajos en pacientes con casi todas las enfermedades renales y su progresión, los métodos de evaluación de uEGF deben estandarizarse para ser utilizados como biomarcadores en la práctica clínica. (AU)

Estimating mortality and disability in Peru before the COVID-19 pandemic: a systematic analysis from the Global Burden of the Disease Study 2019.

Background: Estimating and analyzing trends and patterns of health loss are essential to promote efficient resource allocation and improve Peru's healthcare system performance. Methods: Using estimates from the Global Burden of Disease (GBD), Injuries, and Risk Factors Study (2019), we assessed mortality and disability in Peru from 1990 to 2019. We report demographic and epidemiologic trends in terms of population, life expectancy at birth (LE), mortality, incidence, prevalence, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) caused by the major diseases and risk factors in Peru. Finally, we compared Peru with 16 countries in the Latin American (LA) region. Results: The Peruvian population reached 33.9 million inhabitants (49.9% women) in 2019. From 1990 to 2019, LE at birth increased from 69.2 (95% uncertainty interval 67.8-70.3) to 80.3 (77.2-83.2) years. This increase was driven by the decline in under-5 mortality (-80.7%) and mortality from infectious diseases in older age groups (+60 years old). The number of DALYs in 1990 was 9.2 million (8.5-10.1) and reached 7.5 million (6.1-9.0) in 2019. The proportion of DALYs due to non-communicable diseases (NCDs) increased from 38.2% in 1990 to 67.9% in 2019. The all-ages and age-standardized DALYs rates and YLLs rates decreased, but YLDs rates remained constant. In 2019, the leading causes of DALYs were neonatal disorders, lower respiratory infections (LRIs), ischemic heart disease, road injuries, and low back pain. The leading risk factors associated with DALYs in 2019 were undernutrition, high body mass index, high fasting plasma glucose, and air pollution. Before the COVID-19 pandemic, Peru experienced one of the highest LRIs-DALYs rates in the LA region. Conclusion: In the last three decades, Peru experienced significant improvements in LE and child survival and an increase in the burden of NCDs and associated disability. The Peruvian healthcare system must be redesigned to respond to this epidemiological transition. The new design should aim to reduce premature deaths and maintain healthy longevity, focusing on effective coverage and treatment of NCDs and reducing and managing the related disability.

Risk of Testing Positive for COVID-19 among Healthcare and Healthcare-Related Workers.

Understanding the risk factors associated with COVID-19 infection among healthcare workers is crucial for infection prevention and control. The aim of this study was to examine the risk of testing positive for COVID-19 among a multicenter cohort of workers, taking into account their occupational roles (medical professionals, staff in operational and administrative roles, or laboratory personnel) in healthcare settings. The data analyzed in this study included 2163 individuals with suggestive COVID-19 symptoms who underwent laboratory testing. The incidence rate in the study sample was calculated to be 15.3 cases per 10,000 person-days. The results from the multiple regression model indicated that job roles were not significantly associated with the risk of testing positive. However, age and the duration of the pandemic were identified as significant risk factors, with increasing age and longer pandemic duration being associated with a higher risk of testing positive. Additionally, vaccination was found to reduce the risk of testing positive. These findings provide valuable insights into COVID-19 transmission among indoor healthcare workers, highlighting the influence of age, pandemic duration, and vaccination on infection risk. Further research is needed to develop evidence-based strategies aimed at protecting healthcare workers and preventing virus spread in healthcare settings.

Assessing the Relationship between Annual Surface Temperature Changes and the Burden of Dengue: Implications for Climate Change and Global Health Outcomes.

Dengue fever remains a significant global health concern, imposing a substantial burden on public health systems worldwide. Recent studies have suggested that climate change, specifically the increase in surface temperatures associated with global warming, may impact the transmission dynamics of dengue. This study aimed to assess the relationship between annual surface temperature changes from 1961 to 2019 and the burden of dengue in 185 countries. The dengue burden was evaluated for 2019 using disability-adjusted life years (DALYs) and the annual rate of change (ARC) in DALY rates assessed from 1990 to 2019. A cross-sectional and ecological analysis was conducted using two publicly available datasets. Regression coefficients (ß) and 95% confidence intervals (CI) were used to examine the relationship between annual surface temperature changes and the burden of dengue. The results revealed a significant negative relationship between mean surface temperatures and DALY rates in 2019 (ß = -16.9, 95% CI -26.9 to -6.8). Similarly, a significant negative relationship was observed between the temperature variable and the ARC (ß = -0.99, 95% CI -1.66 to -0.32). These findings suggest that as temperatures continue to rise, the burden of dengue may globally decrease. The ecology of the vector and variations in seasons, precipitation patterns, and humidity levels may partially contribute to this phenomenon. Our study contributes to the expanding body of evidence regarding the potential implications of climate change for dengue dynamics. It emphasizes the critical importance of addressing climate change as a determinant of global health outcomes.

Regional and national burden of prostate cancer: incidence, mortality, years of life lost, and disability-adjusted life years, in Mexico and Latin America from 1990 to 2019.

PURPOSE: Prostate cancer (PC) is the second leading cause of cancer and the fifth cause of cancer-related death. This manuscript aims to determine the incidence, mortality, and Disability Adjusted Life Years (DALYs) trends of PC in the last 30 years in Latin America and Mexico. METHODS: We performed a cross-sectional analysis of a publicly available data set. Data regarding the burden of prostate cancer in 20 Latin-American countries, and the 32 states of Mexico, were retrieved from the Global Burden of Disease Study 2019. Collected information included incidence and mortality rates (per 100,000), as well as the DALYs as absolute numbers and rates (per 100,000) and the annual rates of change in rates from 1990 to 2019. RESULTS: In Latin America in males aged 55 years or older, the mean incidence rate was 344 cases per 100,000. The number of deaths attributable to prostate cancer observed was 67,110 and the mean mortality rate was 210 per 100,000. The overall burden of disease was 1,120,709 DALYs and the contribution of years of life lost (YLL) was 91.7% ([Formula: see text] = 1,027,946). Mexico presented an incidence rate (279.6) and mortality (99.1) rate (per /100 thousand). In Mexico, 13 states had a DALYs' rate above the national mean (883 per 100,000) and the highest burden (1360 DALYs/100,000) were documented in the state of Guerrero (Southwestern Mexico). CONCLUSION: Only two Latin-American countries (Brazil and Colombia) and eight states of Mexico showed a decreased trend about the rate of change of DALYs in the last 30 years.

Animal models of kidney iron overload and ferroptosis: a review of the literature.

In recent years, it has been identified that excess iron contributes to the development of various pathologies and their complications. Kidney diseases do not escape the toxic effects of iron, and ferroptosis is identified as a pathophysiological mechanism that could be a therapeutic target to avoid damage or progression of kidney disease. Ferroptosis is cell death associated with iron-dependent oxidative stress. To study the effects of iron overload (IOL) in the kidney, numerous animal models have been developed. The methodological differences between these models should reflect the IOL-generating mechanisms associated with human IOL diseases. A careful choice of animal model should be considered for translational purposes.

Predictors of ICU Admission in Children with COVID-19: Analysis of a Large Mexican Population Dataset.

Children, although mostly affected mildly or asymptomatically, have also developed severe coronavirus disease 2019 (COVID-19). This study aims to assess potential predictors of intensive care unit (ICU) admission in a large population (n = 21,121) of children aged 0-9 years with laboratory-confirmed disease. We performed a cross-sectional analysis of a publicly available dataset derived from the normative epidemiological surveillance of COVID-19 in Mexico. The primary binary outcome of interest was admission to the ICU due to respiratory failure. Results showed that immunosuppressed children and those with a personal history of cardiovascular disease had a higher likelihood of being admitted to the ICU, while increasing age and the pandemic duration were associated with a lower likelihood of admission. The study's results have the potential to inform clinical decision-making and enhance management and outcomes for children affected by COVID-19 in Mexico.

Assessing the Burden of Dengue during the COVID-19 Pandemic in Mexico.

The transmission of the dengue virus in Mexico has historically been high, and its burden during the COVID-19 pandemic is currently not well understood. Our objective was to assess the burden of dengue-related disability-adjusted life years (DALYs) between 2020 and 2022. We conducted a cross-sectional analysis of databases resulting from an epidemiological surveillance of vector-borne diseases and computed DALYs using the protocol of the Global Burden of Disease (GBD) study 2019. Our results showed that there were 218,807 incident cases of dengue during the study period, resulting in 951 deaths. The calculated DALYs (and their 95% confidence intervals) were 8121 (7897-8396), 4733 (4661-4820), and 8461 (8344-8605) in 2020, 2021, and 2022, respectively. The DALY rates (per 100,000) were 6.5 (6.3-6.6), 3.8 (3.7-3.9), and 6.7 (6.6-6.8), respectively. The rates for 2020 and 2022 were similar to the historical mean (6.4, p = 0.884), whereas the rate for 2021 was lower than the mean. Premature mortality (years of life lost, YLL) contributed to 91% of the total burden. Our findings suggest that dengue fever remained a significant cause of disease burden during the COVID-19 pandemic, especially in terms of premature mortality.

Predictors of Recurrent Laboratory-Confirmed Symptomatic SARS-CoV-2 Infections in a Cohort of Healthcare Workers.

BACKGROUND: Repeated SARS-CoV-2 infections are plausible and related published data are scarce. We aimed to identify factors associated with the risk of recurrent (three episodes) laboratory-confirmed symptomatic SARS-CoV-2 infections. METHODS: A retrospective cohort study was conducted, and 1,700 healthcare workers were enrolled. We used risk ratios (RR) and 95% confidence intervals (CI) to evaluate the factors associated with symptomatic SARS-CoV-2 infections. RESULTS: We identified 14 participants with recurrent illness episodes. Therefore, the incidence rate was 8.5 per 10,000 person months. In a multiple-model study, vaccinated adults (vs. unvaccinated, RR = 1.05 [1.03-1.06]) and those with a severe first illness episode (vs. mild disease, RR = 1.05 [1.01-1.10]) were at increased risk for repeated symptomatic SARS-CoV-2 reinfections. Increasing age showed a protective effect (per each additional year of age: RR = 0.98 [0.97-0.99]). CONCLUSIONS: Our results suggest that recurrent SARS-CoV-2 infections are rare events in adults, and they seem to be determined, partially, by vaccination status and age.

Clinical Characteristics in the Acute Phase of COVID-19 That Predict Long COVID: Tachycardia, Myalgias, Severity, and Use of Antibiotics as Main Risk Factors, While Education and Blood Group B Are Protective.

BACKGROUND: Risk factors for developing long COVID are not clearly established. The present study was designed to determine if any sign, symptom, or treatment of the acute phase, or personal characteristics of the patient, is associated with the development of long COVID. METHODS: A cohort study was carried out, randomly selecting symptomatic COVID-19 patients and not vaccinated. The severity of the acute illness was assessed through the number of compatible COVID-19 symptoms, hospitalizations, and the symptom severity score using a 10-point visual analog scale. RESULTS: After multivariate analysis, a severity score ≥8 (RR 2.0, 95%CI 1.1-3.5, p = 0.022), hospitalization (RR 2.1, 95%CI 1.0-4.4, p = 0.039), myalgia (RR 1.9, 95%CI 1.08-3.6, p = 0.027), tachycardia (RR 10.4, 95%CI 2.2-47.7, p = 0.003), and use of antibiotics (RR 2.0, 95%CI 1.1-3.5, p = 0.022), was positively associated with the risk of having long COVID. Higher levels of education (RR 0.6, 95%CI 0.4-0.9, p = 0.029) and type positive B blood group (B + AB, RR 0.44, 95%CI 0.2-0.9, p = 0.044) were protective factors. The most important population attributable fractions (PAFs) for long COVID were myalgia (37%), severity score ≥8 (31%), and use of antibiotics (27%). CONCLUSIONS: Further studies in diverse populations over time are needed to expand the knowledge that could lead us to prevent and/or treat long COVID.

Gender and age-related variations in human immunodeficiency virus infection trends at the Mexican Institute of Social Security: 2003-2017.

INTRODUCTION: Diagnosing and treating human immunodeficiency virus carriers has led to the identification of a higher prevalence of said infection and, therefore, of a higher risk of transmission of the virus. OBJECTIVE: To find out the trend of new cases of human immunodeficiency virus infection carriers at the Instituto Mexicano del Seguro Social (IMSS) in Mexico within the 2003-2017 period. METHODS: Patients affiliated to the IMSS were analyzed. Data from 42,181 newly-diagnosed cases were collected, with variations related to gender and age being observed. Age-standardized rates per 100,000 population were obtained. RESULTS: The highest mean annual percentage change in males was documented in adolescents (13.0, 95% CI = 9.9, 16.1). Heterogeneous trends were recorded for women, with a significant overall decrease (-2.2, 95% CI = -3.4, -1.0), but growing trends were also observed in some groups. CONCLUSIONS: Our results suggest that the human immunodeficiency epidemic in patients cared for at the Instituto Mexicano del Seguro Social is concentrated in males, with a growing trend particularly in adolescents.

INTRODUCCIÓN: Hacer el diagnóstico y tratar a portadores del virus de la inmunodeficiencia humana ha llevado a identificar mayor prevalencia de esa infección y, por lo tanto, de un mayor riesgo de transmisión de este virus. OBJETIVO: Conocer la tendencia en México de los nuevos casos de portadores de infección por el virus de la inmunodeficiencia humana en el Instituto Mexicano del Seguro Social (IMSS) en el periodo 2003-2017. MÉTODOS: Se analizaron pacientes asegurados en el IMSS. Se obtuvieron datos de 42 181 casos recién diagnosticados y se analizaron las variaciones relacionadas con el sexo y la edad. Se obtuvieron las tasas estandarizadas por edad por 100 000 personas. RESULTADOS: El cambio porcentual anual promedio más alto en hombres se documentó en adolescentes varones (13.0, IC 95 % = 9.9, 16.1). Se registraron tendencias heterogéneas en las mujeres, con una disminución total significativa (­2.2, IC 95 % = ­3.4, ­1.0), pero también se observaron tendencias crecientes en algunos grupos. CONCLUSIONES: Los resultados sugieren que en el IMSS, la epidemia de la inmunodeficiencia humana adquirida se concentra en hombres, con tendencia creciente particularmente en adolescentes.

Insight into the Burden of Malignant Respiratory Tumors and their Relationship with Smoking Rates and Lead Contamination in Mexico.

We aimed to report the results from the Global Burden of Disease Study 2019 related to respiratory malignant tumors (tracheal, bronchial, and lung) in Mexico. We also evaluated the relationship between the burden of these neoplasms and the proportion of daily smokers and total lead emissions in 2019. A cross-sectional analysis of ecological data was performed. The burden of these tumors was 152,189 disability-adjusted life-years (DALYs), and years of life lost (YLL) contributed to 99% of them. The highest DALYs rates (per 100,000) were observed in the states of Sinaloa, Chihuahua, Baja California Sur, Sonora, and Nayarit. We documented a linear relationship between the DALYs rates and the prevalence of daily smokers (ß = 8.50, 95% CI 1.58-15.38) and the total lead emissions (tons/year: ß = 4.04, 95% CI 0.07-8.01). If later replicated, our study would provide insight into the major relevance of regulating tobacco use and the activities associated with the production of lead dust and other hazardous contaminants.

Reemerging Influenza Virus Infections during the Dominance of the Omicron SARS-CoV-2 Variant in Mexico.

The burden of influenza in Mexico has been high. We aimed to characterize its epidemiological patterns before and during the coronavirus disease 2019 (COVID-19) pandemic. A retrospective cohort study was conducted and 5652 PCR-confirmed cases of influenza (October 2019-April 2022) were analyzed. The highest incidence (144 per million) was observed in December 2019 and rapidly decreased right before the start of the pandemic (February 2020). No cases were documented in the 2020-2021 season, and infections reemerged at a low level (8 per million) in December 2021. The case-fatality rates were around 5% in both seasons (p = 0.591). The dominant strains were AH1N1 and AH3N2 in the 2019-2020 and 2021-2022 seasons, respectively. In multiple analysis, males and older patients were at increased risk of a fatal outcome. Flu vaccination and infection by B lineages (vs. AH1N1) showed a protective effect. Our results suggest that the spread of the influenza virus reemerged in the 2021-2022 season when the SARS-CoV-2 Omicron variant (B.1.1.529) was dominant. Efforts focusing on the prevention of transmission of respiratory viral pathogens, together with flu vaccination, may be useful to reduce the risk of an influenza outbreak.

Waning immunity to SARS-CoV-2 following vaccination or infection.

We use survival analysis to analyze the decay in the protection induced by eight SARS-CoV-2 vaccines using data from 33,418 fully anonymized patients from the IMSS public health system in Mexico, including only previously vaccinated, confirmed SARS-CoV-2 positive with a PCR test. We analyze the waning effect in those with complete vs. incomplete dose fitting a Weibull distribution. We compare these results with an estimate of the waning effect due to active infection. In two-dose vaccines, we found that the average protection time of a complete dose increases 2.6 times compared to that of an incomplete dose. All analyzed vaccines provided a protection that lasted longer than the protection due to active infection, except in those patients that did not fulfilled the complete dose. The average protection of a full dose is 2.2 times larger than that provided by active infection. The average protection of active infection is about the same as the average protection of an incomplete dose. All evaluated vaccines had lost most of their protective effect between 8 and 11 months of application of first shot. Our results highly correlate with NT50 and other estimates of vaccine efficacy. We found that on average, vaccination increases Age50, the age at which there is a 50% probability of severe disease if infected, in 15 years. We also found that Age50 increases with mean protection time.