Associations of ambient air pollutants with regional pulmonary tuberculosis incidence in the central Chinese province of Hubei: a Bayesian spatial-temporal analysis
ENVIRONMENTAL HEALTH
Authors: Liu, Fuqiang; Zhang, Zhixia; Chen, Hongying; Nie, Shaofa
Abstract
Background Air pollution and pulmonary tuberculosis (PTB) are still serious worldwide problems, especially in areas of developing countries. Whether there is an association between high ambient air pollutant concentrations and PTB has not been fully explored. Methods Bayesian spatial-temporal models were constructed to analyse the association between ambient air pollutants (particulate matter with aerodynamic diameters of <= 10 mu m (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2)) and PTB incidence, adjusting for socioeconomic covariates. We collected data on pulmonary TB, ambient air pollution (PM10, SO2 and NO2) concentrations and socioeconomic covariates from 17 prefectures in the central Chinese province of Hubei between Jan 1, 2006, and Dec 31, 2015. Results For every annual 10 mu g/m(3) increase in SO2, the relative risk (RR) of PTB incidence was 1.046 (95% credible interval [CI], 1.038-1.054) in the study area. Moreover, we found positive associations with each annual 10 mu g/m(3) increase in ambient air pollutants (PM10, SO2 and NO2) in females but only with SO2 in males. A significant association for each 10 mu g/m(3) increase in SO2 was observed in all the age groups, with a significant association for PM10 only in children under 14 years of age. A significant response relationship was also observed at a 0-1 month moving average lag for each 10 mu g/m(3) increase in SO2. Conclusions High ambient air pollution concentrations in areas of developing countries might increase the risk of regional PTB incidence, especially for women and young people. Precautions and protective measures and efforts to reduce ambient air pollutant concentrations should be strengthened in developing countries.
BCG Infection due to MPT64-Negative Strain: A Diagnostic Challenge
AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE
Authors: Suresh, Parasmal; Biswas, Lalitha; Prasad, Vinitha; Kumar, Anil; Sivadas, Suchitra; Khan, Sadia; Biswas, Raja
Abstract
MPT64 is a 24-kDa immunogenic protein that is widely used as a diagnostic marker for the differentiation of Mycobacterium tuberculosis complex (MTBC) from nontuberculous Mycobacterium (NTM). Unlike Mycobacterium bovis, Bacillus Calmette-Guerin(BCG) vaccine strains with RD2 deletion do not secrete MPT64. Culture isolates from infections due to these strains may be falsely identified as nontuberculous Mycobacterium in the absence of clinical correlation. Here, we present one case each of BCG adenitis and osteitis, both of which were considered as MPT64 card-negative Mycobacterium spp. (i.e., NTM) and were later identified as M. bovis BCG Danish 1331 strain. The first case was a 4-month-old female infant admitted with swollen lymph nodes in the left supraclavicular and the left axillary region of 1 month duration. The second case was of a 1-year-and-5-month-old male child who presented with a limp on the left leg and soft tissue swelling of 1 month duration on the anterolateral aspect of the left knee joint. In both cases, BCG vaccine was administered at birth on the left deltoid region and had healed without any complication. Clinical samples in both cases were positive by Xpert tuberculosis/RIF for MTBC, and cultures grew acid-fast bacilli which were negative by MPT64 assay. The clinical implication of infections due to M. bovis BCG is immense as they are inherently resistant to pyrazinamide, and the presence of disseminated BCG infection in young children is a hallmark of serious immune deficiency which needs to be ruled out.