The effect of BCG vaccination on infection and antibody levels against SARS-CoV-2-The results of ProBCG: a multicenter randomized clinical trial in Brazil.

OBJECTIVES: Evatuate if Bacillus Calmette-Guérin (BCG) vaccine could be used as a tool against SARS-CoV-2 based on the concept of trained immunity. METHODS: A multicenter, double-blinded, randomized clinical trial recruited health care workers (HCWs) in Brazil. The incidence rates of COVID-19, clinical manifestations, absenteeism, and adverse events among HCWs receiving BCG vaccine (Moreau or Moscow strains) or placebo were compared. BCG vaccine-mediated immune response before and after implementing specific vaccines for COVID-19 (CoronaVac or COVISHIELD) was analyzed. Cox proportional hazard and linear mixed effect modeling were used. RESULTS: A total of 264 volunteers were included for analysis (BCG = 134 and placebo = 130). The placebo group presented a COVID-19 cumulative incidence of 0.75% vs 0.52% of BCG. The Moreau strain also presented a higher incidence rate (1.60% × 0.22%). BCG did not show a protective hazard ratio against COVID-19. In addition, the log (immunoglobulin G) level against SARS-CoV-2 presented a higher increase in the BCG group, whether or not participants had COVID-19, but also without statistical significance. CONCLUSION: Our results suggest that BCG has a tendency of protection against SARS-CoV-2 and higher immunoglobulin G levels than placebo. The clinical trial was registered at https://clinicaltrials.gov/ (NCT04659941).

Long-term respiratory outcomes after COVID-19: a Brazilian cohort study.

Objective: To investigate the prevalence and risk factors for persistent symptoms up to 12 months after hospital discharge in COVID-19 survivors. Methods: This prospective cohort study included patients with COVID-19 discharged from a university hospital in Brazil. Follow-up was performed 2, 6, and 12 months after discharge. Lung function tests and chest computed tomography (CT) were performed 2 months after discharge and were repeated if abnormal. The primary outcomes were the symptoms present, work status, and limitations in daily activities. Results: Eighty-eight patients were included. Dyspnea (54.5%), fatigue (50.0%), myalgia, and muscle weakness (46.6%) were the most common symptoms, which decreased over time. Anxiety was frequent (46.6%) and remained unchanged. One year after discharge, 43.2% of the patients reported limitations in daily activities, and 17.6% had not returned to work. Corticosteroid use was significantly associated with dyspnea and limitations in daily activities. Females had an increased risk of fatigue at the 12-month assessment, with marginal significance after multivariable adjustment. Young age and bronchial wall thickening on admission CT were also risk factors for dyspnea at follow-up. The most common lung function abnormalities were reduced diffusion capacity and small airway disease, which partially improved over time. Conclusions: One year after hospital discharge, more than one-third of patients still had persistent COVID-19-related symptoms, remarkable dyspnea, fatigue, and limitations in daily activities, regardless of acute disease severity. Age, female sex, corticosteroid use during hospitalization, and bronchial thickening on admission CT were associated with an increased risk of sequelae.

Drug susceptibility profile of Mycobacterium kansasii clinical isolates from Brazil.

OBJECTIVES: Mycobacterium kansasii (M. kansasii) pulmonary infection can cause disease with clinical and radiological features similar to tuberculosis. Failure to treat M. kansasii infection is usually associated with resistance; to increase the chance of successful treatment it is important to identify the species and know the susceptibility profile. This study aimed to evaluate the antimycobacterial susceptibility profiles of M. kansasii isolates from Brazil. METHODS: Sixty-nine M. kansasii isolates from 69 patients were identified by partial sequencing of the hsp65 gene, and their susceptibility profiles were analysed by minimal inhibitory concentration (MIC) assays. RESULTS: From 69 isolates, 68 showed susceptibility to clarithromycin, amikacin, and moxifloxacin. Most strains showed high rates of resistance to trimethoprim-sulfamethoxazole and ciprofloxacin. Resistance to rifampicin and ethambutol was found in 12% and 25% of isolates, respectively. CONCLUSIONS: Worrying results were found regarding susceptibility to some drugs used as first-line agents in the treatment of diseases caused by M. kansasii.

Systematic review with meta-analyses and critical appraisal of clinical prediction rules for pulmonary tuberculosis in hospitals.

OBJECTIVE: To systematically review studies evaluating clinical prediction rules (CPRs) for adult inpatients suspected to have pulmonary tuberculosis. DESIGN: Systematic review with meta-analyses. SETTING: Hospitals. Patients Inpatients at least 15 years of age admitted to acute care. METHODS: A search was conducted in 5 indexed electronic databases with no language or year of publication restrictions. We performed a meta-analysis for those CPRs with at least 2 validation studies. Results were reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. RESULTS: Of the 461 abstracts selected, 36 articles were fully analyzed and 11 articles were included, yielding 8 CPRs derived in 4 countries. Broad validation studies were identified for 2 CPRs. The most frequent clinical predictors were fever and weight loss. All CPRs included chest imaging signs. Most CPRs were derived in countries with a low prevalence of pulmonary tuberculosis and included homeless, immigrants, and those who reacted to the purified protein derivative test. Both of the CPRs derived in countries with a high prevalence of pulmonary tuberculosis strongly relied on chest radiograph predictors. Accuracy of the different CPRs was high (area under receiver operating characteristic curve, 0.79-0.91). Meta-analysis of 4 validation studies for Wisnivesky's CPR indicates optimistic pooled results: sensitivity, 94.1% (95% CI, 89.7%-96.7%); negative likelihood ratio, 0.22 (95% CI, 0.12-0.40). CONCLUSION: On the basis of a critical appraisal of the 2 best validated CPRs, the presence of weight loss and/or fever in inpatients warrants obtaining a chest radiograph, regardless of the presence of productive cough. If the chest radiograph is abnormal, the patient should be placed in isolation until more specific test results are available. Validation in different settings is required to maximize external generalization of existing CPRs.

Immunoenzymatic assay for the diagnosis of American tegumentary leishmaniasis using soluble and membrane-enriched fractions from infectious Leishmania (Viannia) braziliensis.

The diagnosis of American tegumentary leishmaniasis (ATL) is based on the visualization or isolation of the parasite, which is a time-consuming and poorly sensitive method. In this study, we evaluated the accuracy and reliability of ELISA for the diagnosis of ATL using soluble (SF) and membrane-enriched (MF) antigen fractions obtained from an infectious strain of Leishmania (Viannia) braziliensis. A total of 152 serum samples investigated at a referral center in Rio de Janeiro, Brazil, between 2005 and 2007 were studied. Each sample was tested twice with each fraction for the calculation of reliability (intraclass coefficient (ICC)). Cut-off values of 0.22 (SF) and 0.33 (MF) were defined. The use of the fractions resulted in good discrimination between patients, with a large area under the curve (P<0.0001), but no difference was observed between the two fractions (P=0.45). Sensitivity was 89.5% for each fraction, specificity was 89.5% for SF and 93.4% for MF, and the positive likelihood ratio was 8.5 for SF and 13.6 for MF. The ICCs were excellent (SF: 0.96 and MF: 0.90). The antigens tested provided precision and accuracy for the diagnosis of ATL, with SF being recommended due to its lower cost and greater practicality.

Comparison of C(18)-carboxypropylbetaine and standard N-acetyl-L-cysteine-NaOH processing of respiratory specimens for increasing tuberculosis smear sensitivity in Brazil.

Techniques to improve the sensitivity of smear microscopy would facilitate early tuberculosis (TB) diagnosis and disease control, especially in low-income countries where the positive predictive value is high. C(18)-carboxypropylbetaine (CB-18) is a zwitterionic detergent that helps to compensate for the innate buoyancy of mycobacteria, potentially enhancing recovery by centrifugation. Previous data suggest that CB-18 may increase the sensitivity of smear, culture, and molecular amplification diagnostic testing. The goal of the present study was to evaluate if the sensitivity of the smear technique using light microscopy could be improved by treating respiratory samples with CB-18. In the first phase, respiratory specimens were collected consecutively from patients with suspected pulmonary tuberculosis in a tertiary-care hospital in Rio de Janeiro, Brazil (236 specimens were analyzed). After protocol modifications, another 120 respiratory specimens were evaluated. The standard technique was N-acetyl-L-cysteine with sodium hydroxide (NALC-NaOH) treatment, smear concentration with centrifugation, and Ziehl-Neelsen staining. Culture on Löwenstein-Jensen slants was performed on all specimens for use as the "gold standard." No specimens from patients undergoing active TB treatment were included. The initial protocol for CB-18 processing resulted in a sensitivity of 59.6% and specificity of 96.8% compared to standard processing with a sensitivity of 66.0% and specificity of 96.8%. Using the modified protocol, the sensitivity of CB-18 increased to 71.4% with a specificity of 97.0% versus standard processing with a sensitivity of 61.9% and a specificity of 99.0%. The diagnostic yield of acid-fast bacillus smear with CB-18 in the absence of fluorescence microscopy and PCR compared to standard processing with NALC-NaOH was not significantly different, although the power to detect a difference by the modified assay was low.