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Brazil currently has one of the fastest growing SARS-CoV-2 epidemics in the world. Due to limited available data, assessments of the impact of non-pharmaceutical interventions (NPIs) on virus transmission and epidemic spread remain challenging. We investigate the impact of NPIs in Brazil using epidemiological, mobility and genomic data. Mobility-driven transmission models for Sao Paulo and Rio de Janeiro cities show that the reproduction number (Rt) reached below 1 following NPIs but slowly increased to values between 1 to 1.3 (1.0 - -1.6). Genome sequencing of 427 new genomes and analysis of a geographically representative genomic dataset from 21 of the 27 Brazilian states identified >100 international introductions of SARS-CoV-2 in Brazil. We estimate that three clades introduced from Europe emerged between 22 and 27 February 2020, and were already well-established before the implementation of NPIs and travel bans. During this first phase of the epidemic establishment of SARS-CoV-2 in Brazil, we find that the virus spread mostly locally and within-state borders. Despite sharp decreases in national air travel during this period, we detected a 25% increase in the average distance travelled by air passengers during this time period. This coincided with the spread of SARS-CoV-2 from large urban centers to the rest of the country. In conclusion, our results shed light on the role of large and highly connected populated centres in the rapid ignition and establishment of SARS-CoV-2, and provide evidence that current interventions remain insufficient to keep virus transmission under control in Brazil.

robust clinical studies on the safety and/or efficacy of chloroquine (CQ) and/or hydroxychloroquine (HCQ) for the treatment of COVID-19 during the recent 2020 pandemic.We searched PubMed and also MedRxiv.org (pre-print server for health sciences, without peer review), without any language restrictions and including Chinese publications, for studies published between Dec 2019 and April 5, 2020, using the search terms 'COVID-19, coronavirus, SARS-Cov-2'. We found three non-randomized studies with limited sample sizes in which (1) HCQ use led to a decrease in SARS-Cov-2 detected in respiratory secretions five days after treatment, together with azithromycin (France, 36 patients); (2) HCQ use shortened time to clinical recovery (China, 62 patients); and (3) CQ was superior to control treatment in inhibiting the exacerbation of pneumonia, improving lung imaging findings, and promoting virus-negative conversion and shortening the disease course (China, 100 patients). We found no published studies comparing different dosages of CQ/HCQ and their thorough safety assessment. Added value of this studyIn a larger patient population, we found that a higher dosage of CQ for 10 days presented toxicity red flags, particularly affecting QTc prolongation. The limited sample size recruited so far does not allow to show any benefit regarding treatment efficacy, however the higher fatality associated with the higher dosage by day 13 of follow-up resulted in a premature halting of this arm. This is the first double-blinded, randomized clinical trial addressing different dosages of CQ for the treatment of severe patients with COVID-19 in the absence of a control group using placebo. Due to the impossibility of not using the drug recommended at the national level, we used historical data from the literature to infer comparisons for lethality endpoints. Follow-up until day 28 is ongoing with a larger sample size, in which long-term lethality will be better estimated.

BackgroundNosocomial infections caused by Pseudomonas aeruginosa presenting resistance to beta-lactam drugs are one of the most challenging targets for antimicrobial therapy, leading to substantial increase in mortality rates in hospitals worldwide. In this context, P. aeruginosa harboring acquired mechanisms of resistance, such as production of metallo-beta-lactamase (MBLs) and extended-spectrum beta-lactamases (ESBLs) have the highest clinical impact. Hence, this study was designed to investigate the presence of genes codifying for MBLs and ESBLs among carbapenem resistant P. aeruginosa isolated in a Brazilian 720-bed teaching tertiary care hospital.MethodsFifty-six carbapenem-resistant P. aeruginosa strains were evaluated for the presence of MBL and ESBL genes. Strains presenting MBL and/or ESBL genes were submitted to pulsed-field gel electrophoresis for genetic similarity evaluation.ResultsDespite the carbapenem resistance, genes for MBLs (blaSPM-1 or blaIMP-1) were detected in only 26.7% of isolates. Genes encoding ESBLs were detected in 23.2% of isolates. The blaCTX-M-2 was the most prevalent ESBL gene (19.6%), followed by blaGES-1 and blaGES-5 detected in one isolate each. In all isolates presenting MBL phenotype by double-disc synergy test (DDST), the blaSPM-1 or blaIMP-1 genes were detected. In addition, blaIMP-1 was also detected in three isolates which did not display any MBL phenotype. These isolates also presented the blaCTX-M-2 gene. The co-existence of blaCTX-M-2 with blaIMP-1 is presently reported for the first time, as like as co-existence of blaGES-1 with blaIMP-1.ConclusionsIn this study MBLs production was not the major mechanism of resistance to carbapenems, suggesting the occurrence of multidrug efflux pumps, reduction in porin channels and production of other beta-lactamases. The detection of blaCTX-M-2,blaGES-1 and blaGES-5 reflects the recent emergence of ESBLs among antimicrobial resistant P. aeruginosa and the extraordinary ability presented by this pathogen to acquire multiple resistance mechanisms. These findings raise the concern about the future of antimicrobial therapy and the capability of clinical laboratories to detect resistant strains, since simultaneous production of MBLs and ESBLs is known to promote further complexity in phenotypic detection. Occurrence of intra-hospital clonal dissemination enhances the necessity of better observance of infection control practices.

A comparison of dengue virus (DENV) antibody levels in paired serum samples collected from predominantly DENV-naive residents in an agricultural settlement in Brazilian Amazonia (baseline seroprevalence, 18.3%) showed a seroconversion rate of 3.67 episodes/100 person-years at risk during 12 months of follow-up. Multivariate analysis identified male sex, poverty, and migration from extra-Amazonian states as significant predictors of baseline DENV seropositivity, whereas male sex, a history of clinical diagnosis of dengue fever, and travel to an urban area predicted subsequent seroconversion. The laboratory surveillance of acute febrile illnesses implemented at the study site and in a nearby town between 2004 and 2006 confirmed 11 DENV infections among 102 episodes studied with DENV IgM detection, reverse transcriptase-polymerase chain reaction, and virus isolation; DENV-3 was isolated. Because DENV exposure is associated with migration or travel, personal protection measures when visiting high-risk urban areas may reduce the incidence of DENV infection in this rural population.