Effectiveness of Bacillus Calmette-Guérin vaccination against severe childhood tuberculosis in China: a case-based, multicenter retrospective study.

BACKGROUND: Evidence varies regarding the efficacy of Bacillus Calmette-Guérin (BCG) vaccine. Data on protection by BCG vaccination against severe tuberculosis (TB) among children in China remain unclear. METHODS: We conducted a case-based, multicenter retrospective study at three children's hospitals in China. Sociological factors affecting BCG vaccination and risk factors associated with disease types were analyzed using a multivariable model. RESULTS: A total 1701 children with active TB were enrolled. Children who were younger, female, residing in a rural area, living in the western regions, and with no BCG vaccination history were at higher risk of developing severe TB. Children with a BCG scar had significantly lower risk for severe TB (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.51-0.67). Children with no BCG scar but who were vaccinated at birth still had lower risk of severe TB types, such as tuberculous meningitis (OR 0.88, 95% CI 0.80-0.97) and miliary TB (OR 0.77, 95% CI 0.69-0.87). CONCLUSIONS: Neonatal BCG vaccination could be an effective means to control TB. In the absence of a new, more effective TB vaccine, our results lend support to continued use of the BCG vaccine in China.

Case Report: Disseminated Mycobacterium intracellulare Infection With More Than 1-Year Follow-Up in a Young Boy With IFNGR1 Deficiency.

All members of the genus Mycobacterium are collectively labeled as "non-tuberculous mycobacterium" (NTM), with the exception of the Mycobacterium tuberculosis complex and M. leprae. Recently, the incidence of NTM infection and number of cases have been increasing, but their identification remains difficult in some countries. Usually, NTM infections and diseases are associated with primary immunodeficiency diseases (PIDs), and their prognoses can be improved with a timely diagnosis and appropriate treatment. Here, we report a case of a 3-year-old boy with disseminated NTM disease (Mycobacterium intracellulare) and interferon-γ receptor 1 (IFNGR1) deficiency. He presented with skin and soft-tissue disease, disseminated osteomyelitis, and pulmonary disease. Initially, we suspected an infection due to the Bacillus Calmette-Guérin vaccine but later suspected Langerhans cell histiocytosis. Following oral treatment of azithromycin, rifampicin, and ethambutol, his condition improved progressively according to clinical and imaging manifestations. This case highlights the importance of early identification of the pathogen in a timely prescription of specific treatments in PIDs patients. We also discuss our experience of treatment of M. intracellulare disease in patients with IFNGR1 deficiency.

Prevalence of Latent Tuberculosis Infection Among Healthy Young Children and Adolescents and a Two-step Approach for the Diagnosis of Tuberculosis Infection in Chengdu, China.

BACKGROUND: China has a high burden of tuberculosis and latent tuberculosis infection (LTBI). The aim of this study was to estimate the prevalence of LTBI among healthy young children and adolescents and test a 2-step approach to explore the threshold for the diagnosis of tuberculosis infection in Chengdu, China. METHODS: Healthy preschool children and school-going children in Chengdu, Sichuan Province, were screened for LTBI using the tuberculin skin test (TST). Preschool children with TST ≥ 5 mm also underwent interferon-γ release assay (IGRA) to explore the threshold of this 2-step approach. RESULTS: In total, 5667 healthy young children and adolescents completed TST test between July 2020 and January 2021 and were included in the present analysis. The age of the participants ranged from 2.4 to 18 years (median 7.25 ± 4.514 years), of which 2093 (36.9%) were younger than 5 years. The overall prevalence of LTBI was 6.37% and 6.64% in children younger than 5 years old. Fourteen of the 341 preschool children with TST ≥5 mm were interferon-γ release assay positive, of which 4 showed a TST result of 5-10 mm, and 6 preschool children received preventive treatment for LTBI. CONCLUSIONS: Healthy young children and adolescents should also be considered as important target populations for LTBI screening. TST can be recommended for first-line screening as part of a 2-step approach for LTBI screening using a positive threshold of 5 mm.

Use of Xpert MTB/RIF Ultra assay on stool and gastric aspirate samples to diagnose pulmonary tuberculosis in children in a high-tuberculosis-burden but resource-limited area of China.

OBJECTIVES: Our study analyzed the performance of Xpert MTB/RIF Ultra (Ultra) on stool and gastric aspirate (GA) samples for the diagnosis of pediatric pulmonary tuberculosis (TB) caused by Mycobacterium tuberculosis in a high-burden area of China. METHODS: Children with presumptive TB were enrolled in two hospitals in Sichuan Province (July 2019-Oct 2020). Because of the unavailability of sputum for etiological testing, gastric samples were aspirated and tested by bacterial culture, acid-fast bacillus microscopy, and Ultra. Stool samples were tested simultaneously using Ultra and Xpert. RESULTS: In total, 141 children with active TB and 34 with non-TB respiratory tract infections were enrolled. Ultra-stool (60.3%, 85/141) and Ultra-GA (52.5%, 74/141) tests were similarly sensitive (p = 0.187). Among the subset of 48 children with confirmed TB, Ultra testing was equally sensitive on stool and GA samples (85.4%, 41/48). The agreement between Ultra-stool and Ultra-GA was moderate in children with active TB (kappa value = 0.527). After integrating Ultra-GA and Ultra-stool outcomes, 70.9% (100/141) of the children were considered to have confirmed TB. The specificities of Ultra-stool and Ultra-GA were 97.1% (33/34) and 100% (34/34), respectively (p = 0.314). CONCLUSIONS: In children, stools can be used as alternative samples to GAs for Ultra tests. Stool- and GA-based Ultra tests are appropriate for bacteriological TB confirmation.