Abstract With the emergence of new variants of SARS-CoV-2, questions about transmissibility, vaccine efficacy, and impact on mortality are important to support decision-making in public health measures. Modifications related to transmissibility combined with the fact that much of the population has already been partially exposed to infection and/or vaccination, have stimulated recommendations to reduce the isolation period for COVID-19. However, these new guidelines have raised questions about their effectiveness in reducing contamination and minimizing impact in work environments. Therefore, a collaborative task force was developed to review the subject in a non-systematic manner, answering questions about SARS-CoV-2 variants, COVID-19 vaccines, isolation/quarantine periods, testing to end the isolation period, and the use of masks as mitigation procedures. Overall, COVID-19 vaccines are effective in preventing severe illness and death but are less effective in preventing infection in the case of the Omicron variant. Any strategy that is adopted to reduce the isolation period should take into consideration the epidemiological situation of the geographical region, individual clinical characteristics, and mask for source control. The use of tests for isolation withdrawal should be evaluated with caution, due to results depending on various conditions and may not be reliable.

ABSTRACT This study aimed to verify socio-demographic and baseline clinical factors associated with death in a hospital cohort of patients with COVID-19. A retrospective cohort study was conducted between February and December 2020 in a university hospital in the city of São Paulo, using Hospital Epidemiology Center data. RT-PCR-positive patients were selected to compose the sample (n = 1,034). At the end of the study, 362 (32%) patients died. In this cohort, age equal to or greater than sixty years (HR = 1.49) and liver disease (HR = 1.81) were independent risk factors for death from COVID-19 associated with higher in-hospital mortality.

ABSTRACT This study aimed to verify socio-demographic and baseline clinical factors associated with death in a hospital cohort of patients with COVID-19. A retrospective cohort study was conducted between February and December 2020 in a university hospital in the city of São Paulo, using Hospital Epidemiology Center data. RT-PCR-positive patients were selected to compose the sample (n = 1,034). At the end of the study, 362 (32%) patients died. In this cohort, age equal to or greater than sixty years (HR = 1.49) and liver disease (HR = 1.81) were independent risk factors for death from COVID-19 associated with higher in-hospital mortality.

Coronaviruses belong to a large family of viruses and, for 60 years, have been a known cause of respiratory infection in humans and animals. In December 2019, a novel coronavirus was identified as responsible for the flu syndrome and severe pulmonary complications, the COVID-19. Its origin, still uncertain, is probably related to a mutation in the coronavirus that infects bats, breaking the genetic barrier to adapt to a new species. The original site of transmission was a seafood and live animal market in the city of Wuhan, China. The first cases were linked to individuals who frequented this market. Later, the virus infected family members and, in geometrical progression, nearby provinces, expanding to several countries in all continents.

Os coronavírus pertencem a uma grande família viral e são conhecidos há 60 anos como causadores de infecções respiratórias em humanos e animais. Em dezembro de 2019, um novo coronavírus foi identificado como causador de síndrome gripal e graves complicações pulmonares, a COVID-19. A origem, ainda incerta, está provavelmente relacionada a uma mutação do coronavírus que infecta morcegos, quebrando a barreira genética para conseguir se adaptar a uma nova espécie. O local inicial de transmissão foi um mercado de frutos do mar e animais vivos na cidade de Wuhan, China. Os primeiros casos foram de indivíduos frequentadores desse mercado. Posteriormente o vírus foi transmitido para familiares e, em progressão geométrica, para províncias próximas, expandindo-se para diversos países de todos os continentes.

ABSTRACT Objective: To determine the incidence of surgical site infection in patients undergoing craniotomy and to compare 12-month and 3-month post-discharge surveillance periods in terms of their impact on the incidence of surgical site infection in those patients. Methods: This was a retrospective cohort study involving 173 adult patients submitted to “clean” craniotomy, with or without implants, during the six-month period, at a university hospital in the city of São Paulo, Brazil. All the patients were evaluated in the pre-, trans- and postoperative periods and were followed for 12 months to analyze the development of surgical site infections. Results: Of the 173 patients undergoing craniotomy during the study period, 20 developed an surgical site infection during the first, and 12 months after discharge, the overall incidence of surgical site infection therefore being 11.56%, compared with a 1-month incidence of 8.67% and a 3-month incidence of 10.98%. Among the 106 patients who received implants, the 1-, 3-, and 12-month incidence of surgical site infection was 7.54% (n= 8), 8.49% (n= 9), and 9.43% (n= 10), respectively. Among the 67 patients who did not receive implants, the 1-, 3-, and 12-month incidence of surgical site infection was 10.44% (n= 7), 14.92% (n= 10), and 14.92% (n= 10), respectively. Conclusion: The incidence of surgical site infection after craniotomy is high. Reducing the duration of the post-discharge surveillance period from 12 months to 3 months did not cause significant losses in the numbers of surgical site infection identified or a substantial decrease in their incidence.

ABSTRACTINTRODUCTION: Monte Carlo simulations have been used for selecting optimal antibiotic regimens for treatment of bacterial infections. The aim of this study was to assess the pharmacokinetic and pharmacodynamic target attainment of intravenous β-lactam regimens commonly used to treat bloodstream infections (BSIs) caused by Gram-negative rod-shaped organisms in a Brazilian teaching hospital.METHODS: In total, 5,000 patients were included in the Monte Carlo simulations of distinct antimicrobial regimens to estimate the likelihood of achieving free drug concentrations above the minimum inhibitory concentration (MIC; fT > MIC) for the requisite periods to clear distinct target organisms. Microbiological data were obtained from blood culture isolates harvested in our hospital from 2008 to 2010.RESULTS: In total, 614 bacterial isolates, including Escherichia coli, Enterobacterspp., Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa, were analyzed Piperacillin/tazobactam failed to achieve a cumulative fraction of response (CFR) > 90% for any of the isolates. While standard dosing (short infusion) of β-lactams achieved target attainment for BSIs caused by E. coliand Enterobacterspp., pharmacodynamic target attainment against K. pneumoniaeisolates was only achieved with ceftazidime and meropenem (prolonged infusion). Lastly, only prolonged infusion of high-dose meropenem approached an ideal CFR against P. aeruginosa; however, no antimicrobial regimen achieved an ideal CFR against A. baumannii.CONCLUSIONS:These data reinforce the use of prolonged infusions of high-dose β-lactam antimicrobials as a reasonable strategy for the treatment of BSIs caused by multidrug resistant Gram-negative bacteria in Brazil.

INTRODUCTION: Enterobacteriaceae strains are a leading cause of bloodstream infections (BSI). The aim of this study is to assess differences in clinical outcomes of patients with BSI caused by Enterobacteriaceae strains before and after introduction of an automated microbiologic system by the microbiology laboratory. METHODS: We conducted a retrospective cohort study aimed to evaluate the impact of the introduction of an automated microbiologic system (Phoenix(tm) automated microbiology system, Becton, Dickinson and Company (BD) - Diagnostic Systems, Sparks, MD, USA) on the outcomes of BSIs caused by Enterobacteriaceae strains. The study was undertaken at Hospital São Paulo, a 750-bed teaching hospital in São Paulo, Brazil. Patients with BSI caused by Enterobacteriaceae strains before the introduction of the automated system were compared with patients with BSI caused by the same pathogens after the introduction of the automated system with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. RESULTS: We evaluated 90 and 106 patients in the non-automated and automated testing periods, respectively. The most prevalent species in both periods were Klebsiella spp. and Proteus spp. Clinical cure/improvement occurred in 70% and 67.9% in non-automated and automated period, respectively (p=0.75). 14-day mortality rates were 22.2% and 30% (p=0.94) and 28-day mortality rates were 24.5% and 40.5% (p= 0.12). There were no significant differences between the two testing periods with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. CONCLUSIONS: Introduction of the BD Phoenix(tm) automated microbiology system did not impact the clinical outcomes of BSIs caused by Enterobacteriaceae strains in our setting.

The nosocomial transmission of tuberculosis is a serious occupational health problem. An effective prevention of this disease includes environmental measures to avoid its dissemination and to reduce the amount of droplet nuclei in the air. It is a descriptive study that aimed to describe the necessary structure for the implementation of an isolation room with negative air pressure for patients with tuberculosis. The units were projected with HVAC system with temperature control at 22 ± 2ºC, air recirculation system, HEPA filters, twenty two air changes per hour and negative air pressure. After repairs and the implementation of the environmental control the functioning of the respiratory isolation was monitored for 12 months. In the event of the negative air pressure becoming neutral the manometers in the room would display the filters saturation level and the need for their replacement. Soon after that the negative air pressure could be restarted. The isolation unit implementation required an investment of US$ 75,000.00 being the monthly repair cost US$ 550.00. The respiratory isolation unit requires specific management strategies so as to ensure the protection of healthcare workers and patients.

La transmisión intrahospitalaria de la tuberculosis es un problema de salud en el trabajo y las medidas efectivas de control incluyen controles ambientales destinados a prevenir la diseminación de la enfermedad y reducir la cantidad de partículas infecciosas en el aire. Este estudio se realizó con el objetivo de describir la estructura necesaria para implementar y operar una unidad de aislamiento para la tuberculosis con presión de aire negativa. La unidad fue diseñada con un sistema de climatización con control de temperatura de 22 ± 2 º C, recirculación del aire, filtros HEPA, veinte cambios de airepor horaypresión negativa. Después del proceso de reforma e implementación de los controles ambientales, el funcionamiento del aislamiento respiratorio fue monitoreado durante doce meses. Las ocasiones en que la presión negativa se convirtió en neutra fueron identificadas por manómetros en las habitaciones y en los filtros, señalando saturación y necesidad de sustitución. En seguida, la presión negativa fue restablecida. La inversión para instalar el aislamiento fue de U$S 75.000,00 y el costo de mantenimiento mensual es de U$S 550,00. La unidad requiere estrategias de gestión adecuadas para garantizar la protección de los profesionales de la salud y de los pacientes.

A transmissão intra-hospitalar da tuberculose consiste em um problema de saúde ocupacional, e as medidas de controle efetivas incluem os controles ambientais que visam prevenir a disseminação dessa doença e reduzir as partículas infecciosas aéreas.Trata-se de um estudo descritivo, realizado com o objetivo de descrever a estrutura necessária para implantar e operacionalizar uma unidade de isolamento para tuberculose com pressão negativa do ar. A unidade foi projetada com um sistema de climatização com controle de temperatura de 22 ± 2ºC, recirculação do ar, filtragem HEPA, 20 trocas de ar por hora e pressão negativa. Após a reforma da unidade e a implantação dos controles ambientais, o funcionamento do isolamento respiratório foi monitorizado por 12 meses. As ocasiões em que a pressão negativa se tornou neutra foram identificadas pelos manômetros nos quartos e nos filtros, indicando a saturação deles e sua substituição. Em seguida, a pressão negativa foi restabelecida. O investimento para a implantação do isolamento foi de 75 mil dólares e o custo mensal de manutenção, 550 dólares. A unidade requer gerenciamento apropriado para assegurar a proteção dos profissionais da saúde e demais pacientes.