Population-level seropositivity trend for SARS-Cov-2 in Rio Grande do Sul, Brazil

ABSTRACT OBJECTIVE To describe the evolution of seropositivity in the State of Rio Grande do Sul, Brazil, through 10 consecutive surveys conducted between April 2020 and April 2021. METHODS Nine cities covering all regions of the State were studied, 500 households in each city. One resident in each household was randomly selected for testing. In survey rounds 1-8 we used the rapid WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds 9-10, we used a direct ELISA test that identifies IgG to the viral S protein (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score using principal components analysis. RESULTS Antibody prevalence in early April 2020 was 0.07%, increasing to 10.0% in February 2021, and to 18.2% in April 2021. In round 10, self-reported whites showed the lowest seroprevalence (17.3%), while indigenous individuals presented the highest (44.4%). Seropositivity increased by 40% when comparing the most with the least exposed. CONCLUSIONS The proportion of the population already infected by SARS-Cov-2 in the state is still far from any perspective of herd immunity and the infection affects population groups in very different levels.

Disco-aproximação e E-teste na pesquisa de enterobactérias produtoras de Beta-lactamase de espectro estendido (ESBL) / Double-disk synergy and E-test in the producing research of enterobacteriaceae of extended-spectrum- beta-lactamase (ESBL)

Atualmente, diferentes bactérias vêm apresentando mecanismos de resistência aos antimicrobianos, destacando-se aqueles associados à produção enzimática. Segundo vários autores, as enterobactérias produtoras de beta-lactamase de espectro estendido(ESBL) continuam proliferando-se rapidamente. Essas enzimas são plamídeo-mediadas e conferem resistência a vários antimicrobianosbeta-lactâmicos. De um total de 60 isolados de bactérias resistentes à cefalotina, obtidos em laboratório de Novo Hamburgo (RS), 23,3% foram positivos nos testes fenotípicos para pesquisa da enzima (classe A de Ambler). Foram empregados, simultaneamente, fitas de E-teste e aproximação de discos, conforme proposto por Jarlier e colaboradores (1988). A última metodologia ofereceu resultados equivalentes ao E-teste, com a vantagem de custo muito inferior. Até o momento da execução deste estudo as amostras não eram triadas nem confirmadas para tal enzima, possibilitando, em cerca de 20% dos pacientes, desfecho clínico não favorável como conseqüência de tratamento inadequado.

Currently different bacteria are showing resistance mechanisms to antimicrobial, especially those associated with enzymeproduction. According to several authors, the species of Enterobacteriaceae family producers of extended-spectrum-beta-lactamase(ESBL) remain proliferating quickly. These enzymes are plasmid mediated and confer resistance to various beta-lactams antimicrobial agents. Within a total of 60 isolates of bacteria resistant to cefalotin, obtained in a hospital of the city of Novo Hamburgo (RS), 23,3% were positive in tests for phenotypic search of the enzyme (class A of Ambler). They had been employees, simultaneously, E-test and double-disk synergy, as considered for Jarlier and collaborators (1988). The last methodology offers resulted equivalents to the E-test with the advantage of very inferior cost. So far the execution of this study, the samples were not screened or confirmed for this enzyme, leading in about 20% of patients, not favorable clinical outcome as a result of inadequate treatment.