Prevalence of drug resistant Mycobacterium tuberculosis among children in China.

The available data on the epidemic of drug resistant tuberculosis (TB) among children in China is limited. This study attempted to clarify the drug resistance profiles of clinical strains isolated from children and estimate risk factors related to acquisition of drug resistance. All Mycobacterium tuberculosis strains from children (age <15 years) and adolescent (age 15-18 years) TB patients received in the strain library of Chinese Center for Disease Control and Prevention between January 2005 and December 2012 were included in the study. A study collection included 450 clinical isolates (100 from children, 159 from adolescents, and 191 from adults) from all over China. Drug susceptibility testing was performed by a proportion method. As a result, the drug resistance and multi-drug resistance (MDR) rates in children were 55% (55/100) and 22% (22/100), respectively. In children with MDR-TB, new cases accounted for 40.9% (9/22). Compared with adults, the drug resistance rates were similar in all subgroups (new cases, previously treated cases and all cases) of children (P > 0.05), except for the lower resistance rate to isoniazid in total cases of children (P = 0.011). Patient related information was included in the MDR-TB association analysis. The treatment history was found to be strongly associated with MDR-TB in all three age groups (P < 0.05). Our results demonstrate that the prevalence of drug resistant TB in children in China is alarmingly high and similar to that seen in adults. In contrast, in adolescents, the drug resistance rate to most tested drugs was lower than in adults. Primary transmission and inadequate treatment are two equally important factors for the high MDR-TB rate in children. Thus, major efforts in the TB control in children should focus on decreasing the transmission of drug resistant TB and early testing of drug resistance.