Clinical and genotypic characteristics of childhood tuberculosis in Chongqing, China

The aims of this study were to assess the prevalence of isolates of Beijing lineage in childhood tuberculosis (TB) and the association between strain family and clinical characteristics. A total of 105 children aged less than 18 years with culture-confirmed TB were evaluated by spoligotyping and the 12-locus mycobacterial interspersed repetitive units–variable number of tandem repeats (MIRU-VNTR) scheme. Of 105 isolates spoligotyped, the major spoligotypes found were Beijing plus Beijing-like lineages (64.8%), followed by T1 lineages (12.3%) and MANU2 lineages (5.7%). MIRU typing identified 72 types that defined 17 clusters and 55 unique isolates. The largest cluster was 223325173533, which belongs to the Beijing lineage. Children in rural areas accounted for 68.8% and 50.5% of the children with TB were older than 5 years. Extrapulmonary tuberculosis accounted for 67.6%, and tuberculous meningitis (TBM) 53.3%. There was no association with clinical characterization (P > 0.05). In conclusion, Beijing isolates are the dominant genotype family in children in China. Beijing and non-Beijing strains did not differ in their propensities to cause extrapulmonary tuberculosis in general or meningitis in particular and there was no significant difference between children infected with Beijing strains and those infected with non-Beijing strains with respect to the clinical features.