Pulmonary Tuberculosis In China Research Articles

Diagnostic Value of Symptom Screening for Pulmonary Tuberculosis in China

ObjectiveTo evaluate the diagnostic value of symptom screening for tuberculosis (TB) case finding defined in National Tuberculosis Control Program in China (China NTP) among elderly people(≥65 years) and younger people(<65 years).MethodsWe made a secondary analysis in a population-based TB prevalence survey in China in 2010. Questionnaire including information for cough and haemoptysis was completed by face to face interview, and then chest radiography was conducted in all eligible participants. Sputum smear and culture were followed for all TB suspects. We calculated the odds ratios (OR), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and the area under the receiver operating characteristic curve (AUC) of using different symptoms for screening to detect bacteriologically positive TB in subpopulations stratified by age 65, to evaluate the performance of symptom screening for TB.FindingsOf 315 newly diagnosed bacteriologically positive TB, 131 patients (41.59%) were elderly, and 48.57% of TB patients were asymptomatic. Nearly 50% patients did not present cough of any duration, and less than half present cough more than 2 weeks, a defined suspected symptom in China NTP. Cough of any duration was reported more in patients aged under 65 than those in elderly, especially for the acute cough (9.78% vs 6.87%). Those symptoms defined by China NTP were reported by less than half participants in two subpopulations. Acute cough (<2 weeks) was an independent predictor of TB in people aged under 65 (adjusted OR: 3.3, 95% CI: 2.0-5.5), but not in those aged 65 and above (adjusted OR: 1.4, 95% CI: 0.7-2.9). The specificity for each symptom was significantly higher in participants aged under 65 (P<0.01), and sensitivities of most symptoms were significantly higher among elderly (P<0.05 or P<0.01). When compared with cough for 2 weeks and more, using cough of any duration for symptom screening increased the sensitivity from 42.9% to 51. % for all participants, and the AUC increased from 0.70 to 0.74 for participants aged under 65 without significant difference.ConclusionsThere is a high percent of asymptomatic TB patients, and those symptoms adopted in China NTP for screening is poorly predictive for TB. The presence of TB symptoms, the sensitivities and specificities of symptoms for TB were distinct between two subpopulations cut by age 65, implying different case finding strategies should be established for them. The current case finding strategy should be improved, and further studies should be done to evaluate the performance and cost-effectiveness of different symptom screening strategy.

Enzyme-linked immunosorbent assay using Mycobacterium tuberculosis antigen 5 for the diagnosis of pulmonary tuberculosis in China.

Measurement of serum IgG antibody to Mycobacterium tuberculosis antigen 5 by enzyme-linked immunosorbent assay was evaluated as a serodiagnostic test for pulmonary tuberculosis in China. The test was 89% sensitive and 94 to 100% specific with high accuracies of prediction. Among 82 tuberculous patients, antibody titer was related to the extent of pulmonary disease. Among control subjects, false positive tests were encountered among 5 of 52 persons with other pulmonary disease and not among 30 healthy subjects. The characteristics of this test compare favorably with those reported for sputum smear examination.

Transmission of Mycobacterium tuberculosis in China: a population-based molecular epidemiologic study.

Understanding the transmission of Mycobacterium tuberculosis is essential for the development of efficient tuberculosis control strategies. China has the second-largest tuberculosis burden in the world. Recent transmission and infection with M. tuberculosis, particularly drug-resistant strains, may account for many new tuberculosis cases. We performed a population-based molecular epidemiologic study of pulmonary tuberculosis in China during 1 July 2009 to 30 June 2012. We defined clusters as cases with identical variable number tandem repeat genotype patterns and identified the risk factors associated with clustering, by logistic regression. Relative transmission rates were estimated by the sputum smear status and drug susceptibility status of tuberculosis patients. Among 2274 culture-positive tuberculosis patients with genotyped isolates, there were 705 (31.0%) tuberculosis patients in 287 clusters. Multidrug-resistant (MDR) tuberculosis (adjusted odds ratio [aOR], 1.86; 95% confidence interval [CI], 1.25-2.63) and infection with a Beijing family strain (aOR, 1.56; 95% CI, 1.23-2.96) were associated with clustering. Eighty-four of 280 (30.0%) clusters had a putative source case that was sputum smear negative, and 30.6% of their secondary cases were attributed to transmission by sputum smear-negative patients. The relative transmission rate for sputum smear negative compared with sputum smear-positive patients was 0.89 (95% CI, .68-1.10), and was 1.51 (95% CI, 1.00-2.24) for MDR tuberculosis vs drug-susceptible tuberculosis. Recent transmission of M. tuberculosis, including MDR strains, contributes substantially to tuberculosis disease in China. Sputum smear-negative cases were responsible for at least 30% of the secondary cases. Interventions to reduce the transmission of M. tuberculosis should be implemented in China.

Pulmonary tuberculosis caused by Mycobacterium bovis in China.

The epidemiology of Mycobacterium bovis infection in humans in China is unknown. In this study, pulmonary tuberculosis caused by M. bovis in China was studied. A total of 4069 clinical strains isolated from sputa during the 2007–2009 nationwide surveillance of drug-resistant tuberculosis in China were analyzed. M. bovis was identified by para-nitrobenzoic acid and thiophen-2-carboxylic acid hydrazide growth tests, spoligotyping and multiplex PCR amplification. In addition, a total of 1828 clinical specimens were recruited from Beijing Chest Hospital (Beijing, China) for Löwenstein-Jensen (LJ) culture, both on standard LJ medium and LJ medium containing 4.5 mg/ml(W/V) sodium pyruvate, the latter being the preferred medium for M. bovis growth. The isolates which demonstrated more vigorous on pyruvate containing medium than on standard LJ medium were then identified by multiplex PCR amplification. Only 1 isolate from the nationwide surveillance was confirmed as M. bovis-BCG. The isolate belonged to a predominant spoligotype SB0120 (ST482). In addition, no M. bovis isolate was acquired by the continuous screening step in Beijing Chest Hospital. M. bovis has a negligible contribution to pulmonary tuberculosis in China, so neither laboratory identification nor clinical treatment of M. bovis infection need be considered in routine work.

Clinical diagnostic performance of the simultaneous amplification and testing methods for detection of the Mycobacterium tuberculosis complex for smear-negative or sputum-scarce pulmonary tuberculosis in China

Background Early detection of pulmonary tuberculosis (PTB) is a big challenge in smear negative and sputum scarce patients in China. Simultaneous amplification and testing methods for detection of the Mycobacterium tuberculosis (MTB) complex (SAT-TB assay) is a novel molecular technique established in our hospital. This method has a high sensitivity and specificity in the lab. In this study, the clinical diagnostic performance of this method in smear-negative or sputum-scarce PTB suspects was investigated and evaluated. Methods Two hundred smear negative and 80 sputum-scarce patients were recruited in this study. Samples that included sputum or bronchial washing fluid were collected and sent for both bacteria culture and SAT-TB assay. Diagnosis for these patients was based on the comprehensive evaluation of chestX- ray/CT study, histology examination, lab results, and treatment response. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for each diagnostic test were investigated and calculated using confirmed tuberculosis (TB) and non-TB cases. The time required for detection of MTB was also measured for each method. Results Ninety-two patients (33%) were diagnosed as definitive TB, 112 patients (40%) were probable PTB, and 76 (27%) were non-TB. The sensitivity, specificity, PPV, and NPV of SAT-TB in smear-negative PTB suspects were 93% (95% CI, 84%-98%), 98% (95% CI, 90%-100%), 98% (95% CI, 91%-100%), and 93% (95% CI, 83%-98%). In sputum scarce PTB suspects, the sensitivity, specificity, PPV, and NPV of the SAT-TB assay on bronchial washing fluids were 90% (95% CI, 74%-98%), 100% (95% CI, 85%-100%), 100% (95% CI, 88%-100%), and 88% (95% CI, 69%-97%). The accuracy of the SAT-TB assay is consistent with the bacteria culture assay. The median time required for detecting MTB in the SAT-TB assay was 0.5 day, which was much faster than bacteria culture (28 days). Conclusions The SAT-TB assay is a fast and accurate method for the detection of MTB. It can be widely applied in the clinic and be an asset in early detection and management of PTB suspects, especially in those patients who are smear negative or sputum scarce.

Impact of diabetes on clinical presentation and treatment outcome of pulmonary tuberculosis in Beijing

Diabetes mellitus (DM) is currently known to be one of the risk factors for pulmonary tuberculosis (PTB) and the proportion of DM in PTB is rising along with the increased prevalence of DM in countries with high PTB burden. This study was designed to explore the impact of DM on clinical presentation and treatment outcome of PTB in China. In an urban setting in Beijing, 1126 PTB patients, 30·6% with positive sputum smear, registered in two PTB dispensaries from January 2010 to December 2011 were screened for DM and were followed up prospectively during PTB treatment. DM was observed in 16·2% of patients with PTB. PTB with DM appeared to be associated with older age and a higher proportion of re-treatment. On presentation, DM was associated with more severe PTB signs with higher proportions of smear positivity [odds ratio (OR) 2·533, 95% confidence interval (CI) 1·779-3·606], cavity (OR 2·253, 95% CI 1·549-3·276) and more symptoms (OR 1·779, 95% CI 1·176-2·690). DM was also associated with non-TB deaths (OR 5·580, 95% CI 2·182-14·270, P < 0·001) and treatment failure (OR 6·696, 95% CI 2·019-22·200, P = 0·002). In Beijing, the findings of this study underlined the need to perform early bi-directional screening programmes and explore the underlying mechanism for different treatment outcomes for PTB with DM.

Geographical distribution regarding the prevalence rates of pulmonary tuberculosis in China in 2010

To describe the geographical distribution regarding the prevalence rates of pulmonary tuberculosis (TB) in 2010, to provide reference for eliminating the regional unbalance of TB prevalence in China. Thiessen Polygon Method, dealing with spatial analysis in geographical information system, was used to analyze data from the 5th national TB epidemiological survey. The prevalence rates of active pulmonary TB(PAPT), Mycobacterium-positive pulmonary TB (PMPT) and smear-positive pulmonary TB (PSPT) were 62-548/100 thousand population (OHTP),0-120/OHTP and 0-68/OHTP, which were all relatively lower in most parts of Beijing, Tianjin, Hebei, Shanghai, Jiangsu, Zhejiang and Shandong than in other areas. PAPT (549-1656/OHTP), PMPT (121-366/OHTP) and PSPT (69-181/OHTP) were relatively higher in most parts of Guangxi, Sichuan, Guizhou, Yunnan, Xizang, Qinghai and Xinjiang than in other areas, in which PAPT, PMPT and PSPT of some areas could be seen as high as 1657-2646/OHTP, 367-625/OHTP and 182-285/OHTP, respectively. PAPT, PMPT and PSPT manifested jigsaw pattern distribution between 320-548/OHTP adn 549-919/OHTP, among 67-120/OHTP, 121-207/OHTP and 208-366/OHTP, and among 38-68/OHTP, 69-115/OHTP and 116-181/OHTP, respectively, in the rest of the provinces or autonomous regions. The geographical distribution for TB prevalence significantly presented the fact that it was relatively low in the eastern parts and high in the western parts, and a jigsaw transition pattern between the low and high rates, in the central part of the country.

Screening and intervention of diabetes mellitus in patients with pulmonary tuberculosis in poverty zones in China: Rationale and study design

BackgroundThe merging epidemics of pulmonary tuberculosis (PTB) and diabetes mellitus (DM) have been raised concerns by many experts but no large scale screening and intervention have been launched yet, especially in low-income areas. The current study aims to understand the prevalence of DM in active PTB patients and evaluate the outcomes of diet and living habit intervention in poverty zones in China. Methods/designA cross-sectional investigation and intervention study will be carried out. At least 7000 active PTB patients will be recruited, together with 7000 nonTB persons from the same community. The project will be divided into two stages. The first stage is to train TB workers on DM screening and regular treatment. Screening and related investigation will be carried out afterwards. The second stage is focussed on intervention. A comprehensive strategy will be utilized to conduct health promotion among the patients, the health providers and the lay public. DiscussionTo our knowledge, this is the first and largest study which focuses on the prevalence of DM in PTB in China. We hypothesize that the current prevalence of DM in PTB in China will be understood and the results of our study will provide important evidence for preventing and controlling DM and PTB.

Spatial analysis on new smear-positive pulmonary tuberculosis in China, 2003 - 2008

To analyze the notification status on new sputum-smear positive pulmonary tuberculosis (TB) over the recent years in China, and identify the clusters to address the related reasons. To spatially and temporally scan the data regarding notification, and to display the results via geographic information system. (1) Spatial analysis identified 6 clusters and their relative risks ranged from 1.03 to 1.83 with statistical significance; (2) Temporal analysis identified there were clusters between 2005 and 2007 in terms of notification on new sputum-smear positive pulmonary TB, and the relative risk was 1.27 (P = 0.001); (3) Spatial and temporal analysis identified 2 clusters and the relative risks of the first class cluster and the second class cluster were 1.35 and 1.49 respectively with statistical significance. Provinces included in the first class cluster were basically the same as these in spatial analysis. Distribution of the notification on new sputum-smear positive pulmonary TB was not stochastic at space, time and space-time, and clusters did exist in China.

Clinical evaluation of a rapid immunochromatographic assay based on the 38 kda antigen of Mycobacterium tuberculosis on patients with pulmonary tuberculosis in China

Setting: A rapid membrane-based antibody assay capable of diagnosing pulmonary tuberculosis within 15 min has been developed using the 38 kDa antigen from Mycobacterium tuberculosis. Objective: To determine the specificity and sensitivity of this assay and evaluate its usefulness in a clinical setting. Design: Sera from patients with active pulmonary tuberculosis were obtained from three hospitals in China. The control groups consisted of patients who were diagnosed with lung diseases other than tuberculosis and healthy subjects. Results: Antibody was detected in 54 of 61 (89%) sputum positive patients and 67 of 91 (74%) sputum negative patients who had been clinically diagnosed as having active pulmonary tuberculosis. Five out of 56 (9%) patients with respiratory diseases other than tuberculosis and 1 out of 30 (3%) healthy controls had a positive antibody response. The overall specificity of the assay was 93% and the positive predictive value was 95%. We conclude that this assay is rapid, sensitive and specific and will be a valuable aid in the clinical diagnosis of pulmonary tuberculosis.