The epidemiology of pulmonary tuberculosis in children in Mainland China, 2009–2015

Tuberculosis (TB) is a serious infectious disease that affects children worldwide, especially infants and children aged less than 15 years. According to the latest report issued by the WHO in 2018, children with TB comprise approximately 10% (aged <15 years) of all TB cases, and thus, approximately 1 million new cases of TB emerge in children globally.1 However, the number of reported cases of child TB greatly differed from the number of estimated cases. It has been estimated that almost two-thirds of all children with active TB have not been reported.2 The low reporting rate of child TB is partially due to the low detection rate. Therefore, the prevention and control of TB in children still faces enormous challenges. In China, the data on the prevalence of TB in children are still from the fourth nationwide random survey of TB reported 19 years ago.3 4 To date, few large-scale epidemiological studies relating to TB in children have been performed in China. The characteristics of TB in children differ from those in adults. The diagnosis of TB in children is more difficult than that in adults because most cases are bacteriologically negative and often have non-specific clinical symptoms and signs.5 6 In 2005, the Chinese Center for Disease Control and Prevention (CDC) developed a web-based Tuberculosis Information Management System (TBIMS) to collect real-time TB data, including on child TB, in 31 provinces in Mainland China.7 However, only the notification of pulmonary TB (PTB) is mandatory under the Chinese Law of Preventing and Controlling Infectious Disease. Based on these data, we reported the incidence of children with PTB notified in China and assessed its epidemiological characteristics from 2009 to 2015 in order to formulate the effective and precise strategy for prevention and treatment. ### Incidence Child TB was defined as …