The prevalence and clinical significance of pulmonary infection due to non-tuberculous mycobacteria in Hong Kong

Abstract

An unexpected increase in positive sputum cultures of non-tuberculous mycobacteria (NTM) was noted in Hong Kong in 1990 compared to previous years, in contrast to a steady decline in the number of positive cultures of Mycobacterium tuberculosis. A retrospective case note study was therefore undertaken to ascertain the clinical importance of the rise in NTM isolates. A representative sample of 183 of the 675 patients with NTM isolates from sputum during 1990 was identified. Cases were assigned to groups according to whether there was evidence of progressive pulmonary disease due to NTM (group 1), persisting colonization without evidence of progressive disease (group 2) or transient isolation of NTM without evidence of progressive disease (group 3). Of 168 cases with adequate clinical and radiological records, 28 (16.7%) represented progressive disease due to NTM and 6 (3.6%) represented persisting colonization. The remainder were both transient and clinically insignificant. Most patients (71%) with progressive pulmonary disease due to NTM had pre-existing lung damage, and 50% had received anti-tuberculous therapy for documented M. tuberculosis previously. The commonest organism involved was the M avium complex. Eighty-six percent of patients with progressive disease and 83% of those with persisting colonization had at least one smear positive sputum specimen, whereas only 2% of patients with sputum contamination had a smear positive sputum sample (P < 0.0001). M. malmoense, M. xenopi and M. fortuitum all appear to be rare causes of significant NTM disease in Hong Kong. However, M. chelonei caused four cases of progressive disease within the study population, two of which were fatal.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-tuberculous mycobacteria I: one year clinical isolates identification in Tertiary Hospital Aids Reference Center, Rio de Janeiro, Brazil, in pre highly active antiretroviral therapy era

“…The most plausible explanation is the high incidence of tuberculosis in Brazil, which cause a relative low prevalence of non-tuberculosis mycobacterial disease. In fact, it is difficult to compare our data for disease due to NTM with those published in other countries because of variation in the study periods, selection criteria and populations studied (Edwards 1970, O'Brien et al 1987, Tsukamura et al 1988, Reich & Johnson 1991, Debrunner et al 1992, Hosker et al 1995. Among the few studies done in Brazil, in two mycobacterial isolation was performed only from sterile sites.…”

Rapid Identification of Mycobacteria from Smear-Positive Sputum Samples by Nested PCR-Restriction Fragment Length Polymorphism Analysis

“…Alternatively, the addition of PCR inhibitor scavengers or the use of a chemiluminescence approach to improve the detection of the restriction-digested DNA fragments might also have to be considered. Recently, the global trend has been toward the isolation from sputum samples of more and more NTM organisms in addition to M. tuberculosis (4,10,15). Based on the statistical results from the Chang Gung Memorial Hospital, which is the largest tertiary medical center in Taiwan, the isolation of NTM increased significantly from 248 (19%) in 2003 to 407 (30%) in 2006 (P Ͻ 0.0005).…”

Health‐related quality of life, comorbidities and mortality in pulmonary nontuberculous mycobacterial infections: A systematic review

“…46 Even between Taiwan and its neighbour, Hong Kong, the prevalence of Mycobacterium aviumintracellulare complex infections differed notably (24% and 54% of NTM isolates, respectively). 27,47 Findings from population-based registries 9,24,25,34,35 may have greater external validity than findings from convenience sampling. 23 We identified a knowledge gap on health outcomes of NTM.…”