Significant Rise in SARS-CoV-2 Reinfection Rate in Vaccinated Hospital Workers during the Omicron Wave: A Prospective Cohort Study.

Background: Relatively low SARS-CoV-2 reinfection rates have been reported in vaccinated individuals, but updates considering the Omicron variant are lacking. Objectives: The objective of the study was to provide a current estimate of the SARS-CoV-2 reinfection rate in a highly immunized population. Methods: A prospective cohort of Mexican hospital workers was followed (March 2020-February 2022). Reinfection was defined as the occurrence of two or more episodes of COVID-19 separated by a period of ≥ 90 days without symptoms. The reinfection rate was calculated as the number of reinfection episodes per 100,000 persons per day. Results: A total of 3732 medical consultations were provided to 2700 workers, of whom 1388 (51.4%) were confirmed COVID-19 cases. A total of 73 reinfection cases were identified, of whom 71 (97.3%) had completed their primary vaccination series and 22 (30.1%) had had a booster dose before the second episode. The overall reinfection rate was 23.1 per 100,000 persons per day (as compared to a rate of 1.9 per 100,000 persons per day before the Omicron wave). Conclusions: The SARS-CoV-2 reinfection rate rose significantly during the Omicron wave despite a high primary vaccination coverage rate. Almost one-third of reinfected workers had a vaccine booster ≥ 14 days before the last COVID-19 episode.

Significant Rise in SARS-CoV-2 Reinfection Rate in Vaccinated Hospital Workers during the Omicron Wave: A Prospective Cohort Study

ABSTRACT Background: Relatively low SARS-CoV-2 reinfection rates have been reported in vaccinated individuals, but updates considering the Omicron variant are lacking. Objective: The objective of the study was to provide a current estimate of the SARS-CoV-2 reinfection rate in a highly immunized population. Methods: A prospective cohort of Mexican hospital workers was followed (March 2020-February 2022). Reinfection was defined as the occurrence of two or more episodes of COVID-19 separated by a period of ≥ 90 days without symptoms. The reinfection rate was calculated as the number of reinfection episodes per 100,000 persons per day. Results: A total of 3732 medical consultations were provided to 2700 workers, of whom 1388 (51.4%) were confirmed COVID-19 cases. A total of 73 reinfection cases were identified, of whom 71 (97.3%) had completed their primary vaccination series and 22 (30.1%) had had a booster dose before the second episode. The overall reinfection rate was 23.1 per 100,000 persons per day (as compared to a rate of 1.9 per 100,000 persons per day before the Omicron wave). Conclusions: The SARS-CoV-2 reinfection rate rose significantly during the Omicron wave despite a high primary vaccination coverage rate. Almost one-third of reinfected workers had a vaccine booster ≥ 14 days before the last COVID-19 episode.

ECMO venovenoso durante procedimiento endoscópico de permeabilización de la vía aérea central en pacientes con riesgo vital: reporte de 2 casos / Use of venovenous extracorporeal membrane oxygenation (ECMO) during endoscopic treatment of central airway obstruction and vital risk: report of 2 cases

Resumen: La oxigenación por membrana extracorpórea (ECMO) es de gran utilidad al proveer soporte ventilatorio a pacientes con hipoxia, pero su utilidad en el manejo de pacientes con obstrucción central de la vía aérea y riesgo vital no ha sido frecuentemente usada. La broncoscopía intervencional como terapia bajo ventilación convencional es de alto riesgo en este tipo de pacientes, pero es posible lograr excelentes resultados al ser asociada a ECMO. Comunicamos el caso clínico de 2 pacientes que presentaban disnea en reposo y falla ven1ila1oria aguda ca1as1rófica debido a una obstrucción casi total del lumen traqueal, de causa tumoral. En ambos pacientes en forma urgente se inició soporte circulatorio mediante ECMO VV, mientras se efectuaba la resección tumoral broncoscópica. Luego de terminada la cirugía traqueal, en ambos pacientes se retiró el soporte, siendo decanulados sin eventos y con una buena evolución clínica posterior. Se discute el beneficio del soporte ECMO en este tipo de pacientes.

Abstract: In patients with severe central airway stenosis bronchoscopy-guided intervention therapy under conventional ventilation conveys a high risk. Extracorporeal membrane oxygenation (ECMO) provides very good cardiopulmonary support, but is rarely used in bronchoscopy-guided interventional therapy. We report 2 patients with resting dyspnea due to severe tumor tracheal obstruction and acute pulmonary failure with imminent vital risk. Both patients were cannulated and the ECMO circuit installed on a nearly emergency basis. Tumors were excised, and the patients weaned from cardiopulmonary bypass uneventfully. Subsequent clinical course was satisfactory in both cases. A brief discussion of this condition is included.

Different Clinical Presentations of Human Rhinovirus Species Infection in Children and Adults in Mexico.

Background: Human rhinoviruses (HRVs) are a common cause of influenza-like illness, with the ability to infect the upper and lower respiratory tracts. In this study we aim to describe the clinical and molecular features of HRV infection in Mexican children and adults. Methods: We performed a hospital-based, 4-year multicenter prospective observational cohort study of patients with influenza-like illness. Participants who tested positive for HRV were included. We described demographic, clinical, and laboratory characteristics and the association between HRV types, illness severity, and clinical outcomes. Results: Of the 5662 subjects recruited, 1473 (26%) had HRV; of those, 988 (67.1%) were adults (≥18 years) and 485 (32.9%) were children. One hundred sixty-seven (11.33%) samples were sequenced; 101 (60.5%) were rhinovirus species A (HRV-A), 22 (13.2%) were rhinovirus species B (HRV-B), and 44 (26.3%) were rhinovirus species C (HRV-C). Among children and adults, 30.5% and 23.5%, respectively, were hospitalized (non-intensive care unit [ICU]). The odds of HRV-C are higher than HRV-A for participants in the ICU (compared to outpatient) and when platelets, lymphocytes, white blood cells, and lactate dehydrogenase are increased. The odds of HRV-C are higher than HRV-A and HRV-B with shortness of breath. The odds of HRV-A are higher than HRV-B, and the odds of HRV-B are higher than HRV-C, when mild symptoms like muscle ache and headache occur. Conclusions: Rhinoviruses are a common cause of influenza-like illness. It is necessary to improve the surveillance, testing, and species identification for these viruses to understand different clinical presentations and risk factors associated with worse outcomes. Clinical Trials Registration. NCT01418287.

Novel and prevalent non-East Asian ALDH2 variants; Implications for global susceptibility to aldehydes' toxicity.

BACKGROUND: Aldehyde dehydrogenase 2 (ALDH2) catalyzes the detoxification of aliphatic aldehydes, including acetaldehyde. About 45% of Han Chinese (East Asians), accounting for 8% of humans, carry a single point mutation in ALDH2*2 (E504K) that leads to accumulation of toxic reactive aldehydes. METHODS: Sequencing of a small Mexican cohort and a search in the ExAC genomic database for additional ALDH2 variants common in various ethnic groups was set to identify missense variants. These were evaluated in vitro, and in cultured cells expressing these new and common variants. FINDINGS: In a cohort of Hispanic donors, we identified 2 novel mutations in ALDH2. Using the ExAC genomic database, we found these identified variants and at least three other ALDH2 variants with a single point mutation among Latino, African, South Asian, and Finnish ethnic groups, at a frequency of >5/1000. Although located in different parts of the ALDH2 molecule, these common ALDH2 mutants exhibited a significant reduction in activity compared with the wild type enzyme in vitro and in 3T3 cells overexpressing each of the variants, and a greater ethanol-induced toxicity. As Alda-1, previously identified activator, did not activate some of the new mutant ALDH2 enzymes, we continued the screen and identified Alda-64, which is effective in correcting the loss of activity in most of these new and common ALDH2 variants. INTERPRETATION: Since ~80% of the world population consumes ethanol and since acetaldehyde accumulation contributes to a variety of diseases, the identification of additional inactivating variants of ALDH2 in different ethnic groups may help develop new 'precision medicine' for carriers of these inactive ALDH2.

Protecciòn Radiològica

El propósito del presente texto es dar a conocer los conceptos y fundamentalmente, la protección radiologica asi como el aspecto legal vigente al respecto. Los tres primeros capítulos se dedican a hacer un breve repaso de los principios físicos sobre el origen y naturaleza de las radiaciones ionizantes, poniendo especial atención en los rayos X y gamma. En los capítulos cuarto, quinto y sexto se discuten los fenómenos de interacción de los rayos X y gamma con la materia, la forma en que depositan su energía en el medio y la forma en que pueden ser detectadas dichas radiaciones mientras que de un modo más resumido, en el capítulo séptimo, se indican los efectos biológicos que tales radiaciones producen en el ser humano ...