FACTORS ASSOCIATED WITH NONTUBERCULOUS MYCOBACTERIAL PULMONARY INFECTIONS

摘要

The incidence of nontuberculous mycobacterial (NTM) pulmonary infections has increased in Thailand and can be challenging to diagnose. The aim of this study was to determine the clinical features, radiographic findings and species of NTM among patients with NTM pulmonary infection or colonization at Srinagarind Hospital, Khon Kaen, Thailand, from January 2012 to December 2016 in order to inform future efforts for early diagnosis of NTM. The criteria used to diagnose NTM infection and colonization were the Amercican Thoracic Society and the Infectious Disease Society of America (ATS / IDSA) 2007 criteria. The medical records of 263 patients diagnosed at the study hospital during the study period with NTM in the respiratory system were reviewed. Thirty-six subjects had a definite pulmonary NTM infection, 17 had a probable pulmonary NTM infection and 210 had NTM colonization. HIV antibody testing was performed on 32 of the definite /probable pulmonary NTM patients: 2 tested positive. Eight definite / probable pulmonary NTM patients had a positive interferon gamma antibody test, of whom 6 had disseminated NTM infections. The most common co-morbidities seen among subjects with definite / probably NTM infection were having a history of pulmonary tuberculosis and having current bronchiectasis. The most common co-morbidities seen among subjects with NTM colonization were cardiovascular disease and diabetes mellitus. The chest radiographic patterns seen most among subjects with definite / probable pulmonary NTM infection were a reticular infiltration (n=31, 58.5%), bronchiectasis (n=29, 54.7%) and nodular lesions (n=24, 45.3%). The areas on the chest radiograph where infiltrations most commonly seen were in the right upper lobe (n=26, 49.1%), right middle lobe (n=19, 35.8%), lingular lobe (n=17, 32.1%) and left upper lobe (n=17, 32.1%). The most common NTM organisms isolated on culture in the subjects with definite/ probable pulmonary NTM infection were: Mycobacterium abscessus (n=21, 39.6%), M. avium complex (n=19, 35.8%), M. fortuitum (n=3, 5.7%), M. scrofulaceum (n= 3, 5.7%), rapid-growing mycobacteria (RGM) (n=3, 5.7%), M. kansasii (n=2, 3.8%) and M. gordonae (n=2, 3.8%). Five factors were significantly associated with definite/ probable pulmonary NTM infection: patient age 28 days (adjusted OR=3.95, 95% CI: 1.91-8.20), having a bronchiectasis pattern on chest X-ray (adjusted OR=2.56; 95% CI: 1.18-5.53) and isolating M. abscessus on culture (adjusted OR=3.25; 95% CI: 1.50-7.02). In conclusion, isolated NTM from respiratory specimens does not necessarily imply infection or require treatment. In our study only twenty percent were denifite / probable pulmonary NTM infection. Early diagnosis and treatment denifite /probable pulmonary NTM subjects will decrease morbidity and mortality. However, treatment subjects with NTM colonization may increase drug toxicity because of long term of treatment.