LEWIS FLETCHER BUSS
Projetos de Pesquisa
Unidades Organizacionais
LIM/46 - Laboratório de Parasitologia Médica, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Scale-free dynamics of COVID-19 in a Brazilian city(2023) POLICARPO, J. M. P.; RAMOS, A. A. G. F.; DYE, C.; FARIA, N. R.; LEAL, F. E.; MORAES, O. J. S.; PARAG, K. V.; PEIXOTO, P. S.; BUSS, L.; SABINO, E. C.; NASCIMENTO, V. H.; DEPPMAN, A.A common basis to address the dynamics of directly transmitted infectious diseases, such as COVID-19, are compartmental (or SIR) models. SIR models typically assume homoge-nous population mixing, a simplification that is convenient but unrealistic. Here we vali-date an existing model of a scale-free fractal infection process using high-resolution data on COVID-19 spread in Sao Caetano, Brazil. We find that transmission can be described by a network in which each infectious individual has a small number of susceptible con-tacts, of the order of 2-5. This model parameter correlated tightly with physical distancing measured by mobile phone data, such that in periods of greater distancing the model re-covered a lower average number of contacts, and vice versa. We show that the SIR model is a special case of our scale-free fractal process model in which the parameter that re-flects population structure is set at unity, indicating homogeneous mixing. Our more gen-eral framework better explained the dynamics of COVID-19 in Sao Caetano, used fewer parameters than a standard SIR model and accounted for geographically localized clusters of disease. Our model requires further validation in other locations and with other directly transmitted infectious agents.(c) 2023 Published by Elsevier Inc.
- SARS-CoV-2 seropositivity and COVID-19 among 5 years-old Amazonian children and their association with poverty and food insecurity(2022) FERREIRA, Marcelo U.; GIACOMINI, Isabel; SATO, Priscila M.; LOURENCO, Barbara H.; NICOLETE, Vanessa C.; BUSS, Lewis F.; MATIJASEVICH, Alicia; CASTRO, Marcia C.; CARDOSO, Marly A.Background The epidemiology of childhood SARS-CoV-2 infection and COVID-19-related illness remains little studied in high-transmission tropical settings, partly due to the less severe clinical manifestations typically developed by children and the limited availability of diagnostic tests. To address this knowledge gap, we investigate the prevalence and predictors of SARS-CoV-2 infection (either symptomatic or not) and disease in 5 years-old Amazonian children. Methodology/Principal findings We retrospectively estimated SARS-CoV-2 attack rates and the proportion of infections leading to COVID-19-related illness among 660 participants in a population-based birth cohort study in the Jurua ' Valley, Amazonian Brazil. Children were physically examined, tested for SARS-CoV-2 IgG and IgM antibodies, and had a comprehensive health questionnaire administered during a follow-up visit at the age of 5 years carried out in January or June-July 2021. We found serological evidence of past SARS-CoV-2 infection in 297 (45.0%; 95% confidence interval [CI], 41.2-48.9%) of 660 cohort participants, but only 15 (5.1%; 95% CI, 2.9-8.2%) seropositive children had a prior medical diagnosis of COVID-19 reported by their mothers or guardians. The period prevalence of clinically apparent COVID19, defined as the presence of specific antibodies plus one or more clinical symptoms suggestive of COVID-19 (cough, shortness of breath, and loss of taste or smell) reported by their mothers or guardians since the pandemic onset, was estimated at 7.3% (95% CI, 5.4-9.5%). Importantly, children from the poorest households and those with less educated mothers were significantly more likely to be seropositive, after controlling for potential confounders by mixed-effects multiple Poisson regression analysis. Likewise, the period prevalence of COVID-19 was 1.8-fold (95%, CI 1.2-2.6-fold) higher among cohort participants exposed to food insecurity and 3.0-fold (95% CI, 2.8-3.5-fold) higher among those born to non-White mothers. Finally, children exposed to household and family contacts who had COVID-19 were at an increased risk of being SARS-CoV-2 seropositive and-even more markedly-of having had clinically apparent COVID-19 by the age of 5 years. Conclusions/Significance Childhood SARS-CoV-2 infection and COVID-19-associated illness are substantially under-diagnosed and underreported in the Amazon. Children in the most socioeconomically vulnerable households are disproportionately affected by SARS-CoV-2 infection and disease. Author summary The epidemiology of childhood COVID-19 in the tropics remains a relatively neglected research topic, in part because SARS-CoV-2 typically causes fewer severe illnesses, hospitalizations, and deaths in children than in adults. Here we show that 45% of 660 participants in a birth cohort study in the Brazilian Amazon had SARS-CoV-2 antibodies at the age of 5 years, although only 5% of them reported previously diagnosed COVID-19 episodes-implying that as many as 8 in 9 SARS-CoV-2 infections had remained undiagnosed in these young children. Only 16% of the seropositive children had reportedly experienced cough, shortness of breath, and/or loss of taste or smell. The most socioeconomically vulnerable participants were more likely to have experienced SARS-CoV-2 infection and overt COVID-19 by the age of 5 years. Importantly, children exposed to household food insecurity, which affects 54% of our study participants, had their COVID-19 risk increased by 76%.
- Healthcare-associated infections on the intensive care unit in 21 Brazilian hospitals during the early months of the coronavirus disease 2019 (COVID-19) pandemic: An ecological study(2023) PORTO, Ana Paula M.; BORGES, Igor C.; BUSS, Lewis; MACHADO, Anna; BASSETTI, Bil R.; COCENTINO, Brunno; BICALHO, Camila S.; CARRILHO, Claudia; RODRIGUES, Cristhieni; NETO, Eudes A. S.; GIRAO, Evelyne S.; PIASTRELLI, Filipe; SAPIENZA, Giovanna; VARKULJA, Glaucia; KOLBE, Karin; PASSOS, Luciana; ESTEVES, Patricia; GITIRANA, Pollyana; FEIJO, Regia D. F.; COUTINHO, Rosane L.; GUIMARAES, Thais; FERRAZ, Tiago L. L.; LEVIN, Anna S.; COSTA, Silvia F.Objective: The coronavirus disease 2019 (COVID-19) pandemic has caused a global health crisis and may have affected healthcare-associated infection (HAI) prevention strategies. We evaluated the impact of the COVID-19 pandemic on HAI incidence in Brazilian intensive care units (ICUs). Methods: In this ecological study, we compared adult patients admitted to the ICU from April through June 2020 (pandemic period) with the same period in 2019 (prepandemic period) in 21 Brazilian hospitals. We used the Wilcoxon signed rank-sum test in a pairwise analysis to compare the following differences between the pandemic and the prepandemic periods: microbiologically confirmed central-line-associated bloodstream infection (CLABSI) and ventilator-associated pneumonia (VAP) incidence density (cases per 1,000 central line and ventilator days, respectively), the proportion of organisms that caused HAI, and antibiotic consumption (DDD). Results: We detected a significant increase in median CLABSI incidence during the pandemic: 1.60 (IQR, 0.44-4.20) vs 2.81 (IQR, 1.35-6.89) (P = .002). We did not detect a significant difference in VAP incidence between the 2 periods. In addition, we detected a significant increase in the proportion of CLABSI caused by Enterococcus faecalis and Candida spp during the pandemic, although only the latter retained statistical significance after correction for multiple comparisons. We did not detect a significant change in ceftriaxone, piperacillin-tazobactam, meropenem, or vancomycin consumption between the studied periods. Conclusions: There was an increase in CLABSI incidence in Brazilian ICUs during the first months of COVID-19 pandemic. Additionally, we detected an increase in the proportion of CLABSI caused by E. faecalis and Candida spp during this period. CLABSI prevention strategies must be reinforced in ICUs during the COVID-19 pandemic.