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BACKGROUND Non-tuberculous mycobacteria (NTMs) cause diseases known as mycobacteriosis and are an important cause of morbidity and mortality. The diagnosis of pulmonary disease caused by NTM is hampered by its clinical similarity with tuberculosis (TB) and by the lack of an accurate and rapid laboratory diagnosis. OBJECTIVES Detect DNA from NTMs directly from lung samples using real-time polymerase chain reaction (qPCR) for amplification of 16S rRNA. Additionally, DNA sequencing ( hsp65 and rpoB genes) was used to identify the species of MNTs. METHODS A total of 68 sputum samples (54 with suspected NTMs and 14 with TB) from patients treated at a referral hospital were used. FINDINGS Of these, 27/54 (50%) were qPCR positive for NTMs and 14/14 TB patients (controls) were qPCR negative with an almost perfect concordance ( Kappa of 0.93) with the Mycobacterium spp. culture. Sequencing confirmed the presence of NTM in all positive samples. The most common species was Mycobacterium gordonae (33%), followed by Mycobacterium abscessus (26%), Mycobacterium fortuitum (22%), Mycobacterium avium (15%) and Mycobacterium peregrinum (4%). MAIN CONCLUSIONS The qPCR technique for detecting NTMs targeting 16S rRNA has the potential to detect NTMs and rapidly differentiate from Mycobacterium tuberculosis . However, it is necessary to identify the species to help in the differential diagnosis between disease and contamination, and to guide the choice of the therapeutic scheme.

Visceral leishmaniasis is a serious zoonosis, and its molecular diagnosis is an important strategy. The detection of Leishmania spp. DNA from biological samples fixed in cards could solve problems related to the collect and transport of biological samples. The purpose of this study was to detect Leishmania spp. by PCR, using canine serum fixed in cards (CSFC). For evaluation, the PCR with DNA extracted from CSFC (PCR/card) was compared to the PCR with DNA from the same serum extracted using the Qiagen kit (PCR/Qiagen) and the immunochromatography test (Rapid test - RT). The results showed that out of the 112 analyzed samples, 12 (10.71%) were positive in the PCR/Qiagen, and of those, only two failed to amplify with DNA extracted from the CSFC. The RT was positive in 11 (9.8%) samples; however, only 3 (2.75%) samples of the total agreed with the detection of Leishmania spp. through PCR. Considering the PCR/Qiagen test as the reference standard for DNA detection, the agreement with the PCR/card was nearly perfect (K = 0.8). The concentration and purity of DNA in the two extractions were not significantly different. The use of PCR with DNA from CSFC showed that it can be an interesting alternative for the diagnosis of leishmaniasis.

Background:The coronavirus disease (COVID-19) pandemic has led to an unprecedented public health crisis. Insufficient testing continues to limit the effectiveness of the global response to the COVID-19 pandemic. Molecular testing methods such as reverse transcriptase polymerase chain reaction (RT-PCR) continue to be highly centralized and are a sub-optimal option for population surveillance. Rapid antigen tests (Ag-RDTs) offer multiple benefits including low costs, high flexibility to conduct tests in a wide variety of settings, and faster return of results. Recently, self-test Ag-RDTs (STs) have gained approval in several markets and offer the possibility to expand testing, reaching at-risk populations. While STs have the potential to assist the COVID-19 response, test result integrity, reporting, and appropriate linkage to care continue to hinder the widespread implementation of self-testing programs. Methods:This protocol presents a mixed-methods pragmatic trial (ISRCTN91602092) to better understand the feasibility of self-testing as part of a contact tracing strategy within the Brazilian public health system. Approximately 604 close contacts of 150 index cases testing positive for COVID-19 will be enrolled. Close contacts will be randomized to either serial (daily) self-testing over a 10-day follow-up period or a more traditional approach to contact tracing with a professional Ag-RDT at one time point post-exposure. Usability workshops and focus group discussions will also be conducted. Discussion:This study protocol presents a comprehensive plan to assess the effectiveness, operational feasibility, and stakeholder preferences of a serial self-testing strategy for contact tracing within the Brazilian public health system. Our results will contribute to better understanding of the feasibility of a self-testing strategy within the public sector. Potential risks and limitations are discussed. Our findings will have important implications as governments continue working to mitigate the impact of COVID-19, particularly in the context of where to direct limited resources for testing and healthcare infrastructure.