The interferon-gamma release assay (IGRA) is more specific than the tuberculin skin test to discriminate between tuberculosis (TB) and nontuberculous mycobacterial (NTM) diseases. Here we performed a retrospective study to evaluate the performance of the T-SPOT.TB in patients with NTM diseases. Between March, 2013 and Nov, 2015, a total of 58 patients with NTM diseases had a T-SPOT.TB performed were enrolled, 30 patients had definite NTM diseases, 28 had probable diseases. Their clinicopathological characteristics were reviewed and analyzed. Cultures for mycobacteria were performed. The indirect proportion method with Löwenstein–Jensen (L-J) medium was used for first-line drug susceptibility test. T-SPOT.TB assay was performed according to the manufacturer’s instructions. Data were expressed as mean ± standard deviation (continuous variables) and as numbers and percentages (categorical variables). The χ2 test was used for comparisons between proportions. The average age was 51.8 ± 16.1 years (range 10 to 77 years), 58.6% (34/58) were male. 16.4% (9/55) were TB-PCR positive. 34 (58.6%) isolates were Mycobacterium intracellulare, ten (17.2%) were Mycobacterium chelonae and seven (12.1%) were Mycobacterium fortuitum. Fifty-two (89.7%) patients were NTM lung disease, five (8.6%) were pleural disease, and one (1.7%) lymphadenitis. The total positivity of T-SPOT.TB was 53.4% (31/58) among the whole group (probable and definite). For probable cases, the T-SPOT.TB assay was positive in 53.5% (15/28); for definite cases, 16 (53.3%) of 30 definite cases were positive. There was no statistical difference in the positivity rate between them (P < 0.01). In the study, we showed that a significant portion of NTM diseases were T-SPOT.TB positive in China. Although T-SPOT.TB is useful diagnostic method for differentiating TB from NTM diseases, in China, the IGRA assay show limited value in the discrimination. In addition, further research is needed to investigate the association between TB infection and treatment for NTM patients.

To describe the demographics, clinical characteristics and microbiologic findings of infant (≤2 years old) tuberculosis (TB) in a high TB burden country. Between Feb, 2007 and Jun, 2015, 115 TB infants who admitted to our hospital were enrolled in the study. Their clinicopathological characteristics were reviewed and analyzed. The mean age was 10.1 ± 7.4 (SD) months, and 84 of 115 infants (73.0 %) were males. 23 patients (20.0 %) had isolated pulmonary TB, 18 patients (15.7 %) had pulmonary and extrapulmonary TB (EPTB), the remaining 74 patients (64.4 %) had exclusively EPTB. The most common site of EPTB was lymph node (n = 61), 54 cases were left axillary lymph node involvement. 49 of 51 patients (96.1 %) were validated by pathological examination, 5 of 57 patients (8.8 %) were positive on acid fast bacilli smear, and 27 of 103 patients (26.2 %) were confirmed by mycobacterial culture. 29 of 59 patients (49.2 %) were PPD positive, 14 of 30 patients (46.7 %) were T-SPOT.TB positive. The most common complaints of patients were lymph node swelling (53.0 %), fever (36.5 %), cough (28.7 %) and dyspnea (10.4 %). There was significant difference in the time before hospital admission among different types of tuberculosis (P < 0.01), fever was also a factor influencing the time (P < 0.05). In infants, the sensitivities of routine TB tests were low and emphasize the need for improved diagnostics; EPTB was more common than pulmonary TB, tuberculous lymphadenitis constituted a high proportion of EPTB; there appears to be an association between the incidence of axillary lymph node TB and BCG vaccination among infants in China.

The retrospective study aimed to evaluate the diagnostic value of bronchial brushing and sputum using acid fast bacilli smear, mycobacterial culture and real-time PCR in detection of pediatric pulmonary tuberculosis, sensitivity and specificity of bronchial brushing and sputum examined by the three methods were calculated and compared to each other. Data showed there were no significant difference in sensitivity between bronchial brushing and matched sputum using each method. But the specificity of real-time PCR on bronchial brushing was lower than on sputum. Compared with bronchial brushing, sputum was better specimen in detection of pediatric pulmonary tuberculosis.

Stool specimen is commonly used for mycobacterial culture to provide critical microbiological evidence for diagnosing tuberculosis (TB) in pediatric patients, especially when obtaining sputum specimens is challenging. However, the utilization of stool specimens for mycobacterial culture continues to face significant challenges in clinical practice, mainly owing to the relatively low diagnostic sensitivity and the frequent contamination by intestinal flora during specimen processing. This study evaluated the effectiveness of power ultrasound (PU) method in improving the recovery of Mycobacterium tuberculosis (M. TB) from stool specimens collected from children suspected of pulmonary tuberculosis (PTB). A total of 252 stool specimens were collected, and each specimen was subsequently divided into approximately three equal groups. One stool specimen was subjected to direct acid-fast bacilli (AFB) smear microscopy, while the other two stool specimens were processed using different decontamination methods(NaOH-NALC method vs. PU method). Out of the 252 specimens, positive cultures were observed in 14 (5.56%) stool specimens treated with the NaOH-NALC method, including M. TB (n = 11, 4.37%) and non-tuberculous mycobacteria (NTM; n = 3, 1.19%). Similarly, among the stool specimens subjected to the PU method, culture positivity was found in 36 (14.28%), comprising of M. TB (n = 24, 9.52%) and NTM (n = 12, 4.76%). The statistical analysis revealed a significant difference in the isolation rate of M. TB and NTM between the two methods (P<0.001). Furthermore, the contamination rate of stool treated with the PU method (14.28%) is significantly lower than that of the NALC-NaOH method (22.62%). In conclusion, our findings indicate that the PU method is a rapid and effective decontamination method for stool in children, improving the detection of active TB among pediatric populations when compared to the NALC-NaOH method.