Clinical and radiological findings in microbiologically defined cases of tübercülosis(TB) and non-tümercülosis mycobacteria(NTM)

Tuberculosis belongs to the group of socioeconomically important infectious diseases with high mortality. It is a disease whose prevalence can be reduced with timely and appropriate effective treatment. Tuberculosis can progress and affect many organs and tissues, such as the lungs, bones, lymph nodes, and pleura (2). Non-tuberculous mycobacteria (NTM) are mycobacterial species that do not belong to the Mycobacterium tuberculosis complex and M. leprae. They occur naturally, in water, and in soil (49). As a result of inhalation of the bacilli, diseases of the lungs, lymph nodes, skin, and soft tissues may occur (8). Tuberculosis and NTM infections are a public health concern that can lead to serious health problems. The sociodemographic characteristics, presence of concomitant diseases, hematological and biochemical evaluation, and radiological features of cases with both forms of infection are important for early diagnosis and treatment. In our study, we investigated the socio-demographic characteristics, concomitant diseases, hematological and biochemical scores and radiological features in both infections. We retrospectively evaluated 417 cases who had at least one of the positivity of direct smear, molecular test and culture directed to the microbiology laboratory for TB and NTM infections between 01/01/2015 and 12/31/2019. We studied the smear positivity, PCR positivity, sociodemographic information, comorbidities, smoking status, hematological and biochemical values, radiological features and mortality status of the cases. The results of our study show that the incidence of NTM has increased compared to previous years. In 2019, there was a significant increase in the NTM group. In the etiological study, it was found that NTM growth was detected in bronchoscopic lavage water. The samples sent to the microbiology laboratory were mostly from the pulmonology department. Pulmonary involvement was more common in NTM infections than in TB related infections. Culture, lavage and acid test results were more significant in the NTM group than in the TB group. PCR and direct smear were significantly positive in TB group. Both groups were predominantly male and had similar mean age. It was found that TB group had predominantly systemic symptoms while NTM group had pulmonary symptoms. The presence of COPD, immunosuppression and history of tuberculosis was significantly higher in the NTM group than in the TB group. Evaluation of the time in which symptoms occurred showed that the NTM group presented to the hospital in a shorter time. The occupational history of the cases could not be clearly evaluated due to the lack of medical history. Mortality conditions were similar in both groups. Elevated CRP, especially above 100, high erythrocyte sedimentation rate, anemia, and lymphopenia were noted in the TB group. The mean platelet count was significantly lower in the NTM group, but was within the range of normal platelet count in both groups. On radiological assessment, nodules, consolidation, cavitation and lymphadenopathy were most common in both groups. The appearance of a "tree-in-bud" was also a common radiological finding in the TB group. When comparing the two groups, it was found that the presence of emphysema and atelectasis was significant in the NTM group. Tuberculosis and NTM infections can cause serious health problems. Therefore, they need to be thoroughly investigated. NTM can be found in water and soil. For this reason, tap water should not be used, especially in endoscopy units, and wash water should be culturally tested regularly. In cases where NTM growth is increasing, the etiology should be investigated by testing for contamination under current hospital conditions. TB and NTM infections can progress to affect many organs other than the lungs. Therefore, TB and NTM infections should be considered and investigated when extrapulmonary infections occur. Every hospital department needs to raise awareness about TB and NTM infections. In cases where TB is suspected, PCR test helps to make the diagnosis faster. For this reason, we recommend that PCR testing be performed whenever TB is suspected, if hospital conditions permit. Symptoms, comorbidities, laboratory and radiological findings of the cases should be studied in detail. In our study, there were limitations in evaluation of comorbidities, occupational history, smoking status and symptoms due to lack of history. The data obtained suggest that COPD, immunosuppression and previous tuberculosis infection predispose to NTM colonization and infection. Laboratory examination, on the other hand, clinically supported the presence of TB infection by the presence of high CRP, high erythrocyte sedimentation rate, anemia and lymphopenia. Radiological examination revealed the presence of emphysema and atelectasis was significant in the NTM group, suggesting that colonization occurs in cases that increase the dead space rate. TB and NTM are infectious diseases that require detailed clinical, laboratory and radiological investigation. Treatment can result in long-term economic losses. For this reason, a complete history should be taken along with detailed laboratory and radiographic examination when cases are presented.