A-288 Molecular Detection of Mycobacterium tuberculosis in Pulmonary and Extra-Pulmonary Samples. Data from a Brazilian Clinical Laboratory

Abstract

Abstract Background Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is among the leading infectious causes of death in developing countries. In humans, TB presents as a progressive granulomatous infectious disease that affects lungs causing pulmonary tuberculosis, but can also affect intestines, meninges, bones, joints, lymph nodes, skin and other body tissues causing extra-pulmonary tuberculosis. The aim of this study was to evaluate the frequency of tuberculosis cases detected during the COVID-19 period and the emergence of cases with extrapulmonary diagnosis. Methods This study was a retrospective analysis from January 2017 to December 2022 based on the analysis of 3105 clinical samples processed by the molecular biology section of AFIP Laboratory. All clinical samples were isolated from pulmonary and extra-pulmonary sites recovered from inpatients admitted in several Brazilian tertiary hospitals. In Brief, the DNA extraction was performed according to the type of patient’s samples and, then submitted to Real-Time PCR (qPCR) method using a commercial kit, which contains specific primers and probes to the M. tuberculosis genome. Results Of the 3105 samples tested, 222 (14%) samples were positive for the presence of M. tuberculosis. Out of which, 120/1405 (8,5%) were detected in the pre-Covid-19 period (2017–2019) and 102/1700 (6%) were detected in Covid-19 period (2020–2022). The prevalence of M. tuberculosis infection was 64.5% and 35.5% among men and females, respectively. The main age range was 41 to 50 years (44.7%), while over 60 years comprised 13.5% of cases (Fig. 1). Between the isolate sites, 67.1% of the M. tuberculosis cases were detected in pulmonary and 32.8% in extra-pulmonary body sites, of which, cerebrospinal fluid and blood are among the most frequent, followed by cervical lymph node, ascitic fluid, gastric lavage, urine and others. A total of 95% of M. tuberculosis was detected in patients assisted by public health service. We did not have access to patient’s symptoms, clinical history or further diagnostic procedures. Conclusion Comparing the two periods of the study, a reduction in the positivity rate of new cases was observed in the pandemic period, perhaps this fact can be associated with restrictions on access to the diagnosis of other pathologies in the pandemic period. Despite no information about the severity of the infection, male gender prevalence and age range from 41 to 50 years group need further attention.