Prevención de eventos de superpropagación de COVID-19 en autobuses que transportaron pacientes presintomáticos / Prevention of COVID-19 superspreader events in buses boarded by presymptomatic patients

Resumen Introducción: Ha ocurrido superpropagación de COVID-19 cuando individuos sintomáticos sin uso de cubrebocas abordaron autobuses. Objetivo: Reportar el riesgo de superpropagación cuando individuos presintomáticos abordaron autobuses junto con pasajeros no vacunados, pero se mantuvieron intervenciones preventivas no farmacológicas. Métodos: Estudio prospectivo de personal de salud transportado durante dos semanas en autobuses a un centro de vacunación contra COVID-19. Fue obligatorio llevar ventanas abiertas, uso correcto de cubrebocas y exclusión de personas con síntomas. La vigilancia prospectiva identificó a trabajadores con COVID-19 los 14 días siguientes a la vacunación. Cada pasajero asintomático de autobuses donde se detectaron casos fue vigilado durante un periodo similar. Los resultados de tamizaje voluntario estuvieron disponibles para los trabajadores que se realizaron prueba el mes previo o el siguiente a la vacunación. Resultados: 1879 trabajadores abordaron 65 autobuses. El tiempo a bordo varió de tres a ocho horas. Veintinueve casos de COVID-19 y cuatro casos asintomáticos fueron identificados entre 613 pasajeros de 21 autobuses. La mediana de tiempo entre la vacunación y el inicio de síntomas de COVID-19 fue de seis días. Fue identificado un caso de transmisión sospechada en autobús. Conclusiones: Las intervenciones preventivas no farmacológicas estrictas redujeron sustancialmente el riesgo de superpropagación de COVID-19 en autobuses ocupados por individuos presintomáticos.

Abstract Introduction: COVID-19 superspreader events have occurred when symptomatic individuals without wearing face masks boarded buses. Objective: To report the risk of superspreader events when presymptomatic individuals boarded buses together with unvaccinated passengers, but with non-pharmacological preventive interventions being maintained. Methods: Prospective study of health personnel transported in buses to a COVID-19 vaccination center for two weeks. Open windows, correct use of face masks and exclusion of symptomatic individuals were mandatory. Prospective surveillance identified workers with COVID-19 within 14 days after vaccination. Each asymptomatic passenger of buses where cases were identified was monitored for a similar time period. Voluntary screening results were available for workers who were tested in the month before or after vaccination. Results: 1,879 workers boarded 65 buses. On-board time ranged from three to eight hours. Twenty-nine cases of COVID-19 and four asymptomatic cases were identified among 613 passengers of 21 buses. Median time between vaccination and COVID-19 symptoms onset was six days. One case of suspected transmission on a bus was identified. Conclusions: Strict nonpharmacological preventive interventions substantially reduced the risk of COVID-19 superspreader events in buses boarded by presymptomatic individuals.

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.

Opinión de un panel de expertos sobre la protección contra la tos ferina en México: el papel de las vacunas acelulares y de células enteras / An expert panel opinion on protection against pertussis in Mexico: The role of acellular and whole-cell vaccines

Resumen La tos ferina es una enfermedad causada por Bordetella pertussis. Aunque es altamente contagiosa, puede ser prevenible por vacunación. Existen dos tipos de vacunas: las de células enteras y las acelulares. La tos ferina ha resurgido en algunos países debido a que su control a escala mundial es heterogéneo. Esta reemergencia se ha relacionado con diversos factores: mayor sensibilidad hacia la infección, mejor detección de la enfermedad, problemas para obtener adecuadas coberturas de vacunación, incremento en los sujetos susceptibles (especialmente menores de 6 meses), pérdida de la inmunidad en los adolescentes y adultos jóvenes, y probables cambios genéticos y adaptativos de B. pertussis. En este documento se analizan las características, las ventajas y las desventajas de las vacunas de células enteras y de las vacunas acelulares. Se presentan las recomendaciones internacionales y se ofrece el posicionamiento de los participantes con respecto a la influencia del uso de vacunas acelulares y las desventajas potenciales de volver a utilizar vacunas de células enteras, en especial por su reactogenicidad. Por último, se analizan las estrategias para lograr un mejor control de la tos ferina en México.

Abstract Pertussis is a highly contagious disease caused by Bordetella pertussis, which may be preventable by vaccination. There are two types of vaccines: whole-cell vaccines and acellular vaccines. Since pertussis control worldwide is heterogeneous, re-emergence of whooping cough has been observed in some countries. This re-emergence has been related to several factors: increased susceptibility to infection, better detection of disease, problems in obtaining adequate vaccination coverage, increase in susceptible subjects (mainly under 6 months of age), loss of immunity in adolescents and young adults, and likely genetic and adaptive B. pertussis changes. This paper discusses whole-cell and acellular vaccines' characteristics, advantages, and disadvantages. International recommendations are presented, and the participants' position is offered regarding the influence of the use of acellular vaccines and the potential disadvantages of reintroducing whole-cell vaccines, mainly due to their reactogenicity. Finally, strategies to achieve better control of pertussis in Mexico are discussed.

Efectividad de las vacunas contra SARS-CoV-2 en hospitalizados con fallas vacunales en 10 hospitales de la CCINSHAE / Effectiveness of SARS-CoV-2 vaccines in hospitalized patients with vaccine failures in 10 CCINSHAE hospitals

Resumen: Objetivo: Evaluar la efectividad de las vacunas contra SARS-CoV-2 para evitar muerte e intubación en pacientes hospitalizados con Covid-19. Material y métodos: Se presentó un análisis de 3 565 hospitalizaciones por SARS-CoV-2 de personas mayores de 20 años de edad, reportadas con fines de salud pública por 10 hospitales de especialidad. Se comparó a los egresados por mejoría (2 094) con los fallecidos (1 471) en modelos mixtos de regresión logística ajustados por edad, sexo, número de comorbilidades y el hospital como variable aleatoria. Resultados: Un esquema completo de vacunación, con cinco tipos de vacunas disponibles, tuvo un efecto protector para muerte o intubación (RM: 0.67, IC95%: 0.54,0.83, 33% de protección); y para muerte (RM: 0.80, IC95%: 0.64,0.99, 20% de protección) estos datos se compararon con los que no habían sido vacunados. Todas las vacunas aplicadas mostraron un efecto protector con un RM<0.8, con intervalos de confianza variables. Conclusiones: El antecedente de vacunación reduce los riesgos de ser intubado y morir, aun en pacientes previamente vacunados y hospitalizados con Covid-19 grave.

Abstract: Objective: To evaluate the effectiveness of SARS-CoV-2 vaccines to avoid death and intubation in hospitalized patients with Covid-19. Materials and methods: We present an analysis of 3 565 hospitalizations for SARS-CoV-2 in people over 20 years of age, reported for public health purposes by 10 specialty hospitals, comparing those discharged for improvement (2 094) with those who died (1 471) in mixed models of logistic regression adjusted for age, sex, number of comorbidities and the reporting hospital as a random variable. Results: A complete vaccination schedule, with five types of vaccine available, had a protective effect for death or intubation (OR: 0.67, CI95%: 0.54,0.83, 33% protection) and for death (OR: 0.80, CI95%: 0.64,0.99, 20% protection) compared to those who had not been vaccinated. All the applied vaccines in the Mexican program showed a protective effect with an OR<0.8, with variable confidence intervals. Conclusions: Even in patients previously vaccinated and hospitalized with severe Covid-19, a history of vaccination reduces the risks of being intubated and dying.

Surge in Ventilator-Associated Pneumonias and Bloodstream Infections in An Academic Referral Center Converted to Treat COVID-19 Patients

Background: Healthcare-associated infections (HAIs) are important adverse events that must be prevented. Objective: The objective of the study was to report and study possible changes in HAI rates as well as their causes after the COVID-19 hospital surge capacity response (HSCR) in an academic referral center. Methods: This was a before-after observational study. The Infection Prevention and Control (IPC) program (prospective surveillance, prevention bundles, antibiotic stewardship, continuing education, and feedback) was transiently disrupted after the start of HSCR (March 2020). HAI rates were compared before (January 2019-February 2020) and after (April-July 2020) HSCR, and plausible predisposing factors in affected patients were compared. Results: An increase in the HAI rate from 6.2 to 11.8 cases/1000 patient-days was noted between periods due to increases in ventilator-associated pneumonia and bloodstream infection (BSI) rates. More critically ill patients were admitted during HSCR, and use of invasive devices increased. Prone positioning and infusion of muscle relaxants became commonplace. The nurse-to-patient ratio in the intensive care unit decreased, and 4 h shifts were introduced to avoid fatigue. The BSI rate decreased after the IPC program with additional measures was reintroduced in May 2020. Conclusions: The strain on the workforce and modifications to the IPC program very possibly underlay the findings. IPC programs continue to be essential during the pandemic.

Factors Associated with COVID-19 and Asymptomatic Carriage in Healthcare Workers of a COVID-19 Hospital

ABSTRACT Background: Risk factors for coronavirus disease (COVID-19) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) asymptomatic carriage (AC) in healthcare workers (HCWs) have been scarcely characterized. Objective: The objective of the study was to study factors associated with COVID-19 and AC in HCWs of a COVID-19 academic medical center. Methods: This is a case-control study. Cases were either symptomatic or asymptomatic HCWs with a positive SARS-CoV-2 polymerase chain reaction (PCR) test result between March 16 and May 21 of 2020. Adjusted odds ratios (aOR) were calculated by means of multivariable logistic regression. In addition, each subject was followed for 14 days to inform outcomes. Results: One hundred thirty of 249 (52.2%) symptomatic HCWs had COVID-19; 10 were hospitalized but none died. Of 987 asymptomatic HCWs, 37 (3.7%) were AC; 6 of the remaining 950 asymptomatic HCWs with a negative PCR test result were found to be presymptomatic COVID-19 cases the following 14 days. Nurses were more frequently present in the COVID-19 group (51.5% vs. 37.0%), but multivariable analysis rendered non-significant results. After adjustment for age, comorbidities, and working place, factors found to be associated with AC were: working in wards as a nurse (aOR = 9.19, 95% confidence interval [CI] = 1.05-80.22, p = 0.045), kitchen personnel (aOR = 4.09, 95% CI = 1.55-10.83, p = 0.005), and being a physician (aOR = 0.12, 95% CI = 0.03-0.54, p = 0.006). Conclusions: HCW category was the predominant factor associated with AC of SARS-CoV-2 in this study.

Clinical and epidemiological characteristics of patients diagnosed with covid-19 in a tertiary care center in Mexico City: a prospective cohort study

ABSTRACT Background: Regional information regarding the characteristics of patients with coronavirus disease (COVID)-19 is needed for a better understanding of the pandemic. Objective: The objective of the study to describe the clinical features of COVID-19 patients diagnosed in a tertiary-care center in Mexico City and to assess differences according to the treatment setting (ambulatory vs. hospital) and to the need of intensive care (IC). Methods: We conducted a prospective cohort, including consecutive patients with COVID-19 from February 26, 2020 to April 11, 2020. Results: We identified 309 patients (140 inpatients and 169 outpatients). The median age was 43 years (interquartile range, 33-54), 59.2% men, and 18.6% healthcare workers (12.3% from our center). The median body mass index (BMI) was 29.00 kg/m2 and 39.6% had obesity. Compared to outpatients, inpatients were older, had comorbidities, cough, and dyspnea more frequently. Twenty-nine (20.7%) inpatients required treatment in the IC unit (ICU). History of diabetes (type 1 or 2) and abdominal pain were more common in ICU patients compared to non-ICU patients. ICU patients had higher BMIs, higher respiratory rates, and lower room-air capillary oxygen saturations. ICU patients showed a more severe inflammatory response as assessed by white blood cell count, neutrophil and platelet count, C-reactive protein, ferritin, procalcitonin, and albumin levels. By the end of the study period, 65 inpatients had been discharged because of improvement, 70 continued hospitalized, and five had died. Conclusions: Patients with comorbidities, either middle-age obese or elderly complaining of fever, cough, or dyspnea, were more likely to be admitted. At admission, patients with diabetes, high BMI, and clinical or laboratory findings consistent with a severe inflammatory state were more likely to require IC.

La pandemia de Coronavirus SARS-CoV-2 (COVID-19): Situación actual e implicaciones para México / The SARS-CoV-2 (COVID-19) coronavirus pandemic: current situation and implications for Mexico

Resumen La pandemia del Coronavirus (COVID-19) es una de las más devastadoras de este siglo. Originada en China en diciembre de 2019 y causada por el virus SARS-CoV-2, en menos de 1 mes ya había sido catalogada como "Emergencia de Salud Pública de Alcance Internacional". A la fecha hay cerca de 3 millones de personas con infección confirmada y ha provocado más de 250,000 fallecimientos en el mundo. Inicialmente afecta las vías respiratorias con neumonías atípica y en casos graves provoca inflamación sistémica con liberación de citoquinas que pueden provocar un rápido deterioro, insuficiencia circulatoria, respiratoria y alteraciones de coagulación con una letalidad cercana al 7%. En México, el primer caso se detectó en febrero del 2020, y a la fecha de esta publicación se cuenta con 29,616 casos confirmados y 2,961 fallecimientos en toda la extensión de país. La baja tasa de muestreo diagnóstico en nuestro país claramente subestima la incidencia e impacto de esta enfermedad. Los grupos mas afectados son aquéllos con factores de riesgo como lo son la edad mayor a 60 años, hipertensión, diabetes o historia de enfermedad cardiovascular. De los casos confirmados, 15% son trabajadores del sector salud. No existe hasta ahora un tratamiento específico o vacuna, de tal manera que es importante contar con las medidas de higiene, aislamiento social y protección personal. Las consecuencias en salud, sociales y económicas podrían ser de gran impacto en los tiempos por venir.

Abstract The Coronavirus pandemic (COVID-19) is one of the most devastating in this century. It originated in China in December 2019 caused by the SARS-Cov-2 virus, and in less than a month it had been classified as an "International Public Health Emergency". To date there are nearly 3 million people infected and more than 250,000 deaths caused by the disease worldwide. Initially it affects the respiratory tract with atypical pneumonia and in severe cases it produces systemic inflammation with cytokine storm that can cause rapid deterioration with circulatory and respiratory failure, coagulopathy and a lethality rate of approximately 7%. In Mexico, the first case was detected in February 2020, and to date there are 26,616 confirmed cases and 2,961 deaths throughout the country. The low number of diagnostic tests conducted in our country clearly underestimates the real incidence and impact of the disease. The most affected groups are those with risk factors such as age over 60, presence of hypertension, diabetes or cardiovascular disease. Of the confirmed cases, 15% are healthcare workers. There is no specific treatment or vaccine yet, so it is important to have hygiene, social isolation and personal protection measures. Health, social and economic consequences could have great impact in the near future.

I. The role of research ethics committees in observational studies: epidemiological registries, case reports, interviews, and retrospective studies

Abstract It is often unclear to the clinical investigator whether observational studies should be submitted to a research ethics committee (REC), mostly because, in general, no active or additional interventions are performed. Moreover, obtaining an informed consent under these circumstances may be challenging, either because these are very large epidemiological registries, or the subject may no longer be alive, is too ill to consent, or is impossible to contact after being discharged. Although observational studies do not involve interventions, they entail ethical concerns, including threats such as breaches in confidentiality and autonomy, and respect for basic rights of the research subjects according to the good clinical practices. In this context, in addition to their main function as evaluators from an ethical, methodological, and regulatory point of view, the RECs serve as mediators between the research subjects, looking after their basic rights, and the investigator or institution, safeguarding them from both legal and unethical perils that the investigation could engage, by ensuring that all procedures are performed following the international standards of care for research. The aim of this manuscript is to provide information on each type of study and its risks, along with actions to prevent such risks, and the function of RECs in each type of study.

Diagnóstico y tratamiento de las infecciones en vías urinarias: un enfoque multidisciplinario para casos no complicados / Diagnosis and treatment of urinary tract infections: a multidisciplinary approach for uncomplicated cases

Las infecciones en vías urinarias afectan tanto a niños como a adultos. En niños son un problema de salud frecuente. En mujeres embarazadas merecen especial atención por los riesgos perinatales. La ausencia de nuevas moléculas antimicrobianas y el incremento en la resistencia bacteriana, favorecida por el uso indiscriminado de antibióticos, obliga a normar conductas para el abordaje y tratamiento inicial de las infecciones en vías urinarias. Este artículo fue desarrollado mediante un panel de médicos especialistas de instituciones de segundo y tercer nivel de atención, tanto públicas como privadas. Se realizó una revisión de la literatura. Ante la sospecha, el diagnóstico de infección en vías urinarias no complicada en niños debe confirmarse a través de medios bacteriológicos. El diagnóstico de infección en vías urinarias no complicada en adultos se realiza con base en el cuadro clínico. El tratamiento empírico inicial debe incluir la cobertura con antibióticos de amplio espectro y la adaptación del mismo de acuerdo con el resultado de los cultivos y de la sensibilidad reportada.

Urinary tract infection affects both children and adults. It is a common health problem in children. In pregnant women, treatment for urinary tract infection deserves special attention due to the perinatal risks. The absence of new antimicrobial molecules and the increase in bacterial resistance, the latter favored by the indiscriminate use of antibiotics, prompt us to standardize norms in the approach and initial treatment of urinary tract infection. The article was written by an independent panel from second- and third-level care public and private institutions. We conducted a review of the literature and the statements made within the framework of an interdisciplinary meeting. When urinary tract infection is suspected in children, diagnosis must be confirmed using bacteriological methods. Diagnosis of uncomplicated urinary tract infection in adults can be made based on the clinical examination. Empirical initial treatment must include wide-spectrum antibiotic options and should be modified according to culture results as well as reported sensitivity.

Pancreatitis crónica, un problema oculto. Estudio clínico patológico de 443 casos / Chronic pancreatitis, an occult problem. A clinical pathological study of 433 cases

Objetivo: establecer la frecuencia de la pancreatitis crónica en pacientes del Hospital General de México, las enfermedades asociadas, complicaciones y frecuencia de diagnóstico clínico correcto. Antecedentes: la pancreatitis crónica tiene signos y síntomas inespecíficos, por lo que rara vez es diagnosticada en vida. Se asocia con alcoholismo y litiasis biliar, dos padecimientos endémicos en nuestro país. Método: se trató de un estudio clínico-patológico, retrospectivo en 20 años (1970-1990) de 15,937 autopsias. Resultados: se encontraron 443 casos de pancreatitis crónica (2.7 por ciento del total de autopsias). El 60 por ciento de los casos ocurrió en hombres, El promedio de edad fue de 50 años. Los casos infantiles fueron excepcionales. Las enfermedades asociadas más frecuentes fueron alcoholismo crónico (66.5 por ciento), cirrosis hepática alcohólica (29.5 por ciento), y litiasis biliar (14.9 por ciento). Las complicaciones más comunes fueron diabetes mellitus (20.7 por ciento) y pseudoquistes pancreáticos (4.6 por ciento). El diagnóstico clínico correcto se hizo tan sólo en 7.4 por ciento Conclusiones: éste es la serie nacional más grande de casos publicados y comprobados por autopsia de pancreatitis crónica. La pancreatitis crónica es un problema clínico oculto, casi exclusivo de los autos, y por lo regular no diagnosticado