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Objective To investigate the current prevalence of nontuberculous mycobacteria (NTM) in Shanghai,and to study the distribution characteristics of NTM clinical isolates,which may help to improve the diagnostic level of NTM and provide guidance for effective prevention and treatment of NTM infection.Methods Culture-positive isolates of clinical mycobacteria were collected from 2008 to 2013 in Huashan Hospital affiliated to Fudan University.All isolates were heat inactivated,and the genomic DNA was extracted and the species were identified by comprehensive comparative analysis of 16S rDNA,hsp65 and rpoB target genes sequencing.Results From January 2008 to December 2013,the overall mycobacterial culture-positive rate was 4.1 ％ (411/10 015).After excluding the repeated isolates,a total of 253 culture-positive mycobacteria isolates were collected for the species identification.By genes sequencing analysis,140 isolates were identified as mycobacterium tuberculosis complex (MTBc),102 NTM and 11 Nocardias,accounting for 55.3％,40.3％ and 4.4％,respectively.Positive rate of NTM isolates had an increasing trend from 25.0％ in 2008 to 42.7％ in 2013,reaching a highest rate of 54.9％ in 2012.In further analysis of 102 NTM isolates,16 species were identified.Among them,28 were M.abscesses,18 strains of M.marinum,17 strains of M.avium-intracellulare complex and 10 strains of M.fortuitum,accounted for 27.5％,17.6％,16.7％ and 9.8％,respectively.Conclusions Both of the isolation number and isolation rate of NTM in the general hospital are increasing.NTM related cases are also increasing in recent years,which mainly caused by M.abscess,M.marinum,M.aviumintracellulare complex and M.fortuitum.
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Objective To investigate the prevalence of tuberculosis among silicosis patients and silica exposure patients,and to analysis the risk factors of tuberculosis among these population.Methods A total of 1 227 silica exposure patients from Wenling,Zhejiang were enrolled in this field study.Basic demographic information was collected and chest X-ray was taken for each patient.Sputum was collected for Mycobacterium tuberculosis culture and strain identification. In univariate analysis,t test was performed for continuous variables andχ2 test for categorical variables.In multivariate analysis,the odds ratio (OR )was calculated along with a 95 % confidence interval (CI )by binary Logistic regression. Results A total of 1 204 silica exposure patients had full basic information and 99.8% were male patients with mean age of (59.4 ± 6.8 )years.The patients in phase 0 + to phase Ⅲ were 172 (14.3%),255 (21 .2%),160 (13.3%)and 617 (51 .2%),respectively.The tuberculosis prevalence rate was about 7.3% among these population.The risk factors for tuberculosis including phase Ⅱ silicosis (OR =2.96, 95 %CI :1 .05 -8.32,P =0.04)and phase Ⅲ silicosis (OR=3.88,95 %CI :1 .58-9.56,P <0.01),and contacting with tuberculosis patients (OR=4.14,95 %CI :1 .91 -8.98,P <0.01).Patients complicated with tuberculosis lacked specific symptoms,but fever and weight loss were more frequent.Conclusion Tuberculosis is highly prevalent in silicotic patients,especially in patients with phase Ⅱ/Ⅲ silicosis and in patients with tuberculosis contact history.
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Objective To evaluate the performance of peripheral blood T-SPOT.TB and cerebrospinal fluid (CSF) interferon (IFN)-γ detection in the diagnosis of tuberculous meningitis (TBM).Methods Among the 182 consecutive cases with suspected TBM in Huashan Hospital from March 2011 to March 2013,30 patients were included in the case group according to the latest diagnostic criteria of TBM.Thirty-nine patients diagnosed with non-tuberculous meningitis were included in the control group.T-SPOT.TB was employed to detect tuberculosis-specific IFN-γ-secreting T cells in the peripheral blood.And IFN-γ in CSF was detected simultaneously by enzyme-linked immunosorbent assay (ELISA) without antigen stimulation.The CSF was collected from 10 patients of TBM group after anti tuberculosis treatment for 4 weeks to observe the dynamic changes.The t-test was used for analysis of continuous variables with normal distribution and Kruskal-Wallis test was used for analysis of variables with abnormal distribution.Results ()f the 30 TBM cases,6 were confirmed cases and 24 were highly suspected cases.The control group was comprised of 12 viral encephalitis,16 suppurative meningitis and 11 cryptococcal meningitis.The positive rate of T-SPOT.TB was significantly higher in TBM group compared with control group (70％ vs 13％,x2 =12.15,P＜0.01).The mean concentration of CSF IFN γ of TBM group was 244.35 pg/mL,which was significantly higher than that of control group 9.48 pg/mL (Z=-4.646,P＜0.01).The CSF IFN-γ was significantly decreased after 4 weeks of treatment (271.02 pg/mL vs 81.36 pg/mL,Z=-3.099,P=0.002).The sensitivity and specificity of peripheral blood T-SPOT.TB in the diagnosis of TBM were 70％ and 87％,respectively.The area under the receiver operating characteristic (ROC) curve of CSF IFN-γ for TBM diagnosis was 0.819; the optimal cut-off point was 81.36 pg/mL; the corresponding sensitivity and specificity were 83 ％ and 85 ％,respectively.Conclusion Both the detection of peripheral blood T-SPOT.TB and CSF IFN-γ are of great importance for the diagnosis of TBM.Dynamic observation of CSF IFN-γ is important for disease monitoring.
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ObjectiveTo evaluate the application of a whole blood interferon-γ (IFN-γ) release assay QuantiFERON-TB Gold In Tube (QFT-GIT) in the diagnosis of tuberculous pleural effusion.Methods IFN-γ released by specific T cells stimulated by early secreted antigenic target 6 × 103protein (ESAT-6),culture filtrate protein 10 (CFP -10) and TB7.7 were measured by QFT-GIT test in 44 tuberculous pleural effusion patients and 16 non-tuberculous pleurisy controls.The IFN-γ release level between groups was compared by Mann-Whitmey test.ResultsThe positive rates of QFT-GIT in patients with tuberculous pleural effusion and non tuberculous pleurisy were 95.5％ and 12.5％,respectively.The sensitivity,specificity,positive predictive value and negative predictive value of QFT-GIT were 95.6％,87.5％,95.6％ and 87.5％,respectively.The antigen-specific IFN-γ release level in the patients with tuberculous pleural effusion was significantly higher than that in non-tuberculous pleurisy controls (P＜0.01).Conclusions The whole blood INF-γ release assay QFT-GIT is a sensitive and specific assay for detecting pleural tuberculosis infection.It could be a useful diagnostic tool for the diagnosis of tuberculous pleural effusion in China.