Effective treatment of tuberculosis (TB) remains a serious public health problem in many countries, including Brazil, especially when considering drug-resistant disease. Xpert MTB/RIF has been implemented in many countries to reduce the time to TB diagnosis and to rapidly detect rifampicin resistance. The study aimed to describe and evaluate Xpert MTB/RIF performance in diagnosing pulmonary TB and rifampicin resistance in a tertiary healthcare facility in Brazil.A cross-sectional study was performed, which included all isolates of confirmed pulmonary TB patients from 2015 to 2018. Both Xpert MTB/RIF and GenoType MTBDRplus assays were performed to detect rifampicin and isoniazid resistance. In addition, isolates with detected resistance to rifampicin and/or isoniazid were analysed by phenotypic testing using MGIT-960 SIRE kit and whole-genome sequencing (WGS) using Illumina MiSeq Sequencing System.2148 respiratory specimens tested with Xpert MTB/RIF were included: n=1556 sputum, n=348 bronchoalveolar lavage and n=244 gastric washing. The overall Xpert MTB/RIF sensitivity in sputum was 94% and the overall specificity was 98%. The negative predictive value in sputum of all the patients was 99% with a positive predictive value of 89%. The concordance between Xpert MTB/RIF and phenotypic susceptibility test was 94.1%, while its concordance with WGS was 78.9%.Xpert MTB/RIF is a rapid and accurate diagnostic strategy for pulmonary TB, which can contribute to improvement in TB control. However, detection of rifampicin resistance might be associated with false-positive results.

BackgroundMalaria is endemic in countries located in tropical and sub-tropical regions. The increasing flow of domestic and international travellers has made malaria a relevant health problem even in non-endemic regions. Malaria has been described as the main diagnosis among travellers presenting febrile diseases after returning from tropical countries. In Brazil, malaria transmission occurs mainly in the Amazon region. Outside this area, malaria transmission is of low magnitude.MethodsThis cross-sectional study aimed to describe the experience in the diagnosis of malaria in a reference centre located outside the Brazilian Amazon Region, emphasizing the differences in clinical and laboratory markers between cases of malaria and those of other febrile diseases (OFD). Medical charts from adult patients (≥18 years) who underwent a thick smear test (TST) for malaria, between January 2001 and December 2014, were retrospectively reviewed.ResultsA total of 458 cases referred to perform the TST were included. Malaria was diagnosed in 193 (42 %) episodes. The remaining 265 episodes (58 %) were grouped as OFD. The majority of malaria episodes were acquired in the Brazilian Amazon Region. The median time between the onset of symptoms and the TST was 7 days. Only 53 (11.5 %) episodes were tested within the first 48 h after symptom onset. Comparing malaria with OFD, jaundice, nausea, vomiting, and reports of fever were more prevalent in the malaria group. Low platelet count and elevated bilirubin levels were also related to the diagnosis of malaria.ConclusionsThe results indicate that outside the endemic area travellers presenting febrile disease suspected of being malaria underwent diagnostic test after considerable delay. The reporting of fever combined with a recent visit to an endemic area should promptly evoke the hypothesis of malaria. In these cases, specific diagnostic tests for malaria should be a priority. For cases that jump this step, the presence of elevated bilirubin or thrombocytopaenia should also indicate a diagnosis of malaria.

Objective:Tuberculosis (TB) transmission in healthcare facilities is still a concern in low-income countries, where airborne isolation rooms are scarce due to high costs. We evaluated the use of single GeneXpert MTB/RIF, the molecular Mycobacterium tuberculosis (MTB) DNA and resistance to rifampicin (RIF) test, as an accurate and faster alternative to the current criteria of 3 negative acid-fast bacilli (AFB) smears to remove patients from airborne isolation.Methods:In this real-world investigation, we evaluated the impact of a single GeneXpert MTB/RIF on the decision making for discharging patients from respiratory isolation. We enrolled patients with suspected pulmonary TB in a public hospital that provides care for high-complexity patients in Brazil. We studied the performance, costs, and time saved comparing the GeneXpert MTB/RIF with AFB smears.Results:We enrolled 644 patients in 3 groups based on the number of AFB smears performed (1, 2, and 3, respectively) on respiratory specimens. GeneXpert MTB/RIF demonstrated good performance compared to AFB smear to rule out TB in all groups. The negative predictive value for AFB smear was 94% (95% confidence interval [CI], 0.90–0.97) and 98% (95% CIs, 0.94–0.99) for GeneXpert MTB/RIF in G3. The isolation discharge based on 3 AFB smears took 84 hours compared to 24 hours with GeneXpert MTB/RIF, which represents 560 patient-days saved in the isolation rooms.Conclusion:A single GeneXpert MTB/RIF is a fast and strong predictor for TB absence in a high-complexity hospital, which is quite similar to results obtained in recent studies in low-burden settings. This molecular test may also increase patient rotation through isolation rooms, with a positive impact in the emergency room and infectious diseases wards.

RESUMO MENON, L.J.B. Aplicação do teste molecular rápido para tuberculose (TB-TRM) na retirada de pacientes de isolamento respiratório em hospital de referência terciária. 2019. 52 f. Dissertação (