Mycobacterium tuberculosis (MTB) is a communicable disease and still remains a threat to common health. Thus, early diagnosis and treatment are required to prevent the spread of infection. Despite the recent advances in molecular diagnostic systems, the commonly used MTB diagnostic tools are laboratory-based assays, such as mycobacterial culture, MTB PCR, and Xpert MTB/RIF. To address this limitation, point-of-care testing (POCT)-based molecular diagnostic technologies capable of sensitive and accurate detection even in environments with limited sources are needed. In this study, we propose simple tuberculosis (TB) molecular diagnostic assay by combining sample preparation and DNA-detection steps. The sample preparation is performed using a syringe filter with amine-functionalized diatomaceous earth and homobifunctional imidoester. Subsequently, the target DNA is detected by quantitative PCR (polymerase chain reaction). The results can be obtained within 2 h from samples with large volumes, without any additional instruments. The limit of detection of this system is 10 times higher than those of conventional PCR assays. We validated the clinical utility of the proposed method in 88 sputum samples obtained from four hospitals in the Republic of Korea. Overall, the sensitivity of this system was superior to those of other assays. Therefore, the proposed system can be useful for MTB diagnosis in limited-resource settings.

Background: Tuberculosis (TB) remains an unresolved public health problem and is the leading cause of death attributable to a single infectious pathogen. The first step in developing strategies to reduce TB mortality is to identify the direct causes of death in patients with TB and the risk factors for each cause. Methods: Data on TB patients systemically collected by the National Surveillance System of South Korea from January 2019 to December 2020 were included in this analysis. We analyzed the clinical characteristics of TB- and non-TB-related deaths, including TB-related symptoms, comorbidities, and radiographic and microbiological findings. Results: A total of 12,340 TB patients (males, 61.1%; mean age, 61.3 years) were included. During the follow-up period, the overall mortality rate was 10.6% (1317 cases), with TB-related deaths accounting for 21.3% (280 cases) of all TB deaths. The median survival time in the TB-related death group was 22 days. TB-related death was associated with older age, lower body mass index (BMI), dyspnea, fever and general weakness, and bilateral radiographic patterns and AFB-positive smears. Non-TB-related deaths were associated with older age, male sex, lower BMI, comorbidities of heart, liver, kidney, and central nervous system (CNS) diseases, CNS TB involvement, the presence of dyspnea, general weakness, and bilateral radiographic patterns. Conclusions: Patients with high-risk TB must be identified through cause-specific mortality analysis, and the mortality rate must be reduced through intensive monitoring of patients with a high TB burden and comorbidities.