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.

Convalescent Plasma to Treat COVID-19: A Two-Center, Randomized, Double-Blind Clinical Trial.

BACKGROUND: The use of convalescent plasma (CP) has been considered for its immunological mechanisms that could benefit patients in moderate and severe stages of COVID-19. This study evaluated the safety and efficacy of the use of donor CP for COVID-19. MATERIAL AND METHODS: A double-blind, randomized controlled clinical trial was conducted from May to October 2020. Thirty-nine participants with moderate (II) and severe (III) stages of COVID-19 confirmed by RT-PCR were included. The study randomization rate was set at 3:1. CPs were chosen for application with a neutralizing antibody titer of ≥1:32. RESULTS: We observed a significantly lower 21-day post-transfusion mortality HR: 0.17 (95.0% CI [0.07-0.45, p < 0.001]) in the group receiving CP compared with the control group; protective units (PU) in the group receiving convalescent plasma after seven days were significantly higher (512 (32-16,384) vs. 96 (32-256), p = 0.01); the PAO2/FIO2 index showed a significant improvement in the group receiving CP (251.01 (109.4) vs. 109.2 (62.4), p < 0.001, in the control group). CONCLUSION: CP is safe and effective, as it decreased mortality in the CP group compared with the control group.

Derivation and validation of sex-specific continuous metabolic syndrome scores for the Mexican adult population.

Traditionally the diagnosis of Metabolic syndrome (MetS) is binary (present/absent). The goal of this work is to propose a sex-specific continuous score to measure the severity of MetS in Mexican adults using waist circumference and body mass index as adiposity measures. MetSx-WC and MetSx-BMI indexes by sex were derived by confirmatory factor analysis (CFA) using data for 6567 adult participants of the National Health and Nutrition Survey 2018. The overall fit of the two proposed CFA models was excellent. We then validated these scores using a community-based health study of 862 university participants and determined that the reliability and strength of agreement between the MetSx-WC and MetSx-BMI scores were excellent. The ROC analysis of the resulting indexes indicates that they have excellent ability to discriminate a MetS classification according to the different criteria. The correlations of MetSx scores and surrogate markers of insulin resistance and obesity ranged from weak to strong. Subsequently, a retrospective study of 310 hospitalized patients with COVID-19 was used to determined that MetSx-BMI score was associated with the mortality of patients with COVID-19. The proposed indices provide a continuous measure in the identification of MetS risk in Mexican adults.

Epidemiological and Clinical Characteristics of Hospitalized Pediatric Patients with SARS-CoV-2 Infection in Mexico City, Mexico.

Background: Evidence from across the world suggests that the pediatric population shows different clinical manifestations and has a lower risk of severe presentation of SARS-CoV-2 infection compared to adults. However, Mexico has one of the highest mortality rates in the pediatric population due to SARS-CoV-2 infection. Therefore, our objective was to explore the epidemiological and clinical characteristics associated with a positive confirmatory test in the Mexican pediatric population admitted to a tertiary care hospital in Mexico City. Methods: Clinical, imaging and laboratory data were retrospectively collected from 121 children hospitalized during the period from March 4th, 2020, to August 8th, 2021. The patients were identified as suspicious cases according to the guidelines of the General Directorate of Epidemiology of Mexico. Real-time polymerase chain reaction (RT-PCR) tests were used to confirm SARS-CoV-2 infection. Categorical variables were compared using the Chi-square test, and propensity score matching was performed to determine univariate and multivariate odds ratios of the population regarding a positive vs. negative SARS-CoV-2 result. Results: Of the 121 children, 36 had laboratory-confirmed SARS-CoV-2 infection. The main risk for SARS-CoV-2-associated pediatric hospitalization was contact with a family member with SARS-CoV-2. It was also found that fever and fatigue were statistically significantly associated with a positive SARS-CoV-2 test in multivariate models. Clinical and laboratory data in this Mexican hospitalized pediatric cohort differ from other reports worldwide; the mortality rate (1.6%) of the population studied was higher than that seen in reports from other countries. Conclusion: Our study found that fever and fatigue at hospital presentation as well as an antecedent exposure to a family member with SARS-CoV-2 infection were important risk factors for SARS-CoV-2 positivity in children at hospital admission.

Interaction of metabolic dysfunction-associated fatty liver disease and nonalcoholic fatty liver disease with advanced fibrosis in the death and intubation of patients hospitalized with coronavirus disease 2019.

Patients with pre-existing liver diseases are considered to have an increased risk of morbidity and mortality from any type of infection, including viruses. The aim of this work was to explore the implications of metabolic dysfunction-associated fatty liver disease (MAFLD) and nonalcoholic fatty liver disease (NAFLD) definitions in coronavirus disease 2019 (COVID-19) and to study the interaction between advanced fibrosis (AF) and each of these diseases in the death and intubation of patients hospitalized with COVID-19. We performed a retrospective study with 359 patients hospitalized with confirmed COVID-19 infection in a tertiary referral hospital who were admitted between April and June 2020. A multivariate Cox model was performed regarding the interaction of AF with MAFLD and NAFLD in the mortality and intubation of patients with COVID-19. The death rate was statistically significantly higher in the MAFLD group compared to the control group (55% vs. 38.3%, p = 0.02). No significant difference was seen in the death rate between the NAFLD and control group. The MAFLD (44.09% vs. 20%, p = 0.001) and NAFLD (40.51% vs. 20%, p = 0.01) groups had statistically significantly higher intubation rates than the control group. A statistically significant interaction between NAFLD and AF was associated with an increase in mortality (p = 0.01), while a statistically significant interaction between MAFLD and AF was associated with an increased risk of mortality (p = 0.006) and intubation (p = 0.049). In the case of patients hospitalized with COVID-19, our results indicate that the death rate was higher in the MAFLD group but not the NAFLD group compared to that in the control group. The intubation rates were higher in the NAFLD and MAFLD groups compared to rates in the control group, suggesting that both could be associated with COVID-19 severity. In addition, we found interactions between AF with MAFLD and NAFLD.

Stability, Bifurcation, and a Pair of Conserved Quantities in a Simple Epidemic System with Reinfection for the Spread of Diseases Caused by Coronaviruses

In this paper, we study a modified SIRI model without vital dynamics, based on a system of nonlinear ordinary differential equations, for epidemics that exhibit partial immunity after infection, reinfection, and disease-induced death. This model can be applied to study epidemics caused by SARS-CoV, MERS-CoV, and SARS-CoV-2 coronaviruses, since there is the possibility that, in diseases caused by these pathogens, individuals recovered from the infection have a decrease in their immunity and can be reinfected. On the other hand, it is known that, in populations infected by these coronaviruses, individuals with comorbidities or older people have significant mortality rates or deaths induced by the disease. By means of qualitative methods, we prove that such system has an endemic equilibrium and an infinite line of nonhyperbolic disease-free equilibria, we determine the local and global stability of these equilibria, and we also show that it has no periodic orbits. Furthermore, we calculate the basic reproductive number R 0 and find that the system exhibits a forward bifurcation: disease-free equilibria are stable when R 0 < 1 / σ and unstable when R 0 > 1 / σ , while the endemic equilibrium consist of an asymptotically stable upper branch that appears from R 0 > 1 / σ , σ being the rate that quantifies reinfection. We also show that this system has two conserved quantities. Additionally, we show some of the most representative numerical solutions of this system. [ FROM AUTHOR] Copyright of Discrete Dynamics in Nature & Society is the property of Hindawi Limited and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)