RESEARCH Infectious diseases in children and adolescents in China: analysis BMJ: first published as 10.1136/bmj.m1043 on 2 April 2020. Downloaded from of national surveillance data from 2008 to 2017 Yanhui Dong,1 Liping Wang,2 David P Burgner,3,4 Jessica E Miller,3,4 Yi Song,1 Xiang Ren,2 Zhongjie Li,2 Yi Xing,1 Jun Ma,1 Susan M Sawyer,3,4,5 George C Patton3,4,5 For numbered affiliations see ABSTRACT 100 000 in 2008 to 162 per 100 000 in 2015, but rose end of the article. OBJECTIVES again to 242 per 100 000 in 2017, largely related to Correspondence to:J Ma To outline which infectious diseases in the pre- mumps and seasonal influenza. Excluding mumps [email protected] (ORCID 0000-0003-3529-1808) covid-19 era persist in children and adolescents in and influenza, the incidence of vaccine preventable Additional material is published China and to describe recent trends and variations by diseases fell from 96 per 100 000 in 2008 to 7 per online only. To view please visit age, sex, season, and province. 100 000 in 2017. The incidence of gastrointestinal the journal online. DESIGN and enterovirus diseases remained constant, but C ite this as: BMJ2020;369:m1043 National surveillance studies, 2008-17. typhoid, paratyphoid, and dysentery continued to http://dx.doi.org/10.1136 bmj.m1043 decline. Vectorborne diseases all declined, with a SETTING Accepted: 12 March 2020 particularly noticeable reduction in malaria. Zoonotic 31 provinces in mainland China. infections remained at low incidence, but there were PARTICIPANTS still unpredictable outbreaks, such as pandemic A/ 4 959 790 Chinese students aged 6 to 22 years with a H1N1 2009 influenza. Tuberculosis remained the most diagnosis of any of 44 notifiable infectious diseases. common bacterial infection, although cases of scarlet The diseases were categorised into seven groups: fever doubled between 2008 and 2017. Sexually quarantinable; vaccine preventable; gastrointestinal transmitted diseases and bloodborne infections and enteroviral; vectorborne; zoonotic; bacterial; and increased significantly, particularly from 2011 to sexually transmitted and bloodborne. 2017, among which HIV/AIDS increased fivefold, MAIN OUTCOME MEASURES particularly in males. Difference was noticeable Diagnosis of, and deaths from, 44 notifiable infectious between regions, with children and adolescents in diseases. western China continuing to carry a disproportionate burden from infectious diseases. RESULTS http://www.bmj.com/ From 2008 to 2017, 44 notifiable infectious diseases CONCLUSIONS were diagnosed in 4 959 790 participants (3 045 905 China’s success in infectious disease control in the males, 1 913 885 females) and there were 2532 pre-covid-19 era was notable, with deaths due to deaths (1663 males, 869 females). The leading infectious diseases in children and adolescents aged causes of death among infectious diseases shifted 6-22 years becoming rare. Many challenges remain from rabies and tuberculosis to HIV/AIDS, particularly around reducing regional inequalities, scaling-up of in males. Mortality from infectious diseases decreased vaccination, prevention of further escalation of HIV/ on 24 September 2021 by guest. Protected copyright. steadily from 0.21 per 100 000 population in 2008 to AIDS, renewed efforts for persisting diseases, and 0.07 per 100 000 in 2017. Quarantinable conditions undertaking early and effective response to highly with high mortality have effectively disappeared. transmissible seasonal and unpredictable diseases The incidence of notifiable infectious diseases in such as that caused by the novel SARS-CoV-2 virus. children and adolescents decreased from 280 per Introduction WH AT IS ALREADY KNOWN ON THIS TOPIC China has undergone a rapid epidemiological transi­ tion, with major reductions in infectious diseases Even though China has made remarkable progress in the control of infectious contributing to an increasing life expectancy from diseases, the susceptibility of children and adolescents has made them a focus 35 years at birth in 1949 to 76.7 years in 2017.1 2 for many infectious disease strategies, including immunisation and enhanced The country successfully eliminated 11 infectious surveillance diseases, including smallpox, in the early 1960s, and No study has yet reported on recent trends in infectious diseases among children a further 10 more recently, including poliomyelitis.3 and adolescents in China An additional 13 diseases, including measles, seem 4 WH AT THIS STUDY ADDS now to be at low endemic levels, and the goal of a national malaria elimination programme that was The incidence of, and deaths from, infectious diseases in children and launched in 2010 is nationwide elimination by 2020.5 adolescents in China continues to decrease China’s success has greatly contributed to worldwide Quarantinable diseases with high lethality have virtually disappeared, sexually reductions in infectious diseases.6 7 transmitted diseases and bloodborne infections pose an increasing problem, In the context of rapid reductions in many infectious and HIV is now the leading cause of death diseases, questions remain about whether current The incidence of zoonotic infections and vectorborne diseases has been low priorities deal with contemporary needs. The epidemics since the epidemic of severe acute respiratory syndrome, but there is potential of severe acute respiratory syndrome (SARS) in 2003 for major outbreaks and the sudden emergence of the new coronavirus the bmj | BMJ 2020;369:m1043 | doi: 10.1136/bmj.m1043 1 RESEARCH disease in 2019(covid­19), highlight new threats and C lassification the need for effective surveillance.8­11 Further global A total of 44 notifiable infectious diseases were BMJ: first published as 10.1136/bmj.m1043 on 2 April 2020. Downloaded from outbreaks over the past decade, including H1N1, included in this study. We adapted and revised H5N1, and H7N9 influenza, Zika virus, yellow fever, Zhang and Wilson’s 2012 classification of 44 CISDCP chikungunya, dengue, and Ebola, reinforce this notifiable infectious diseases into seven major need.12­16 After the SARS outbreak in 2003, China categories reflecting disease causes, characteristics, overhauled its national China Information System for and policy responses.3 The main revisions were Disease Control and Prevention (CISDCP), the world’s the inclusion of hepatitis A, B, and D as vaccine largest internet based notifiable disease reporting preventable diseases. Hepatitis C was classified within system, introducing web based reporting in real time.1 an extended category of sexually transmitted diseases This was accompanied by a major national infectious and bloodborne infections and hepatitis E similarly disease control initiative, with a particular focus on for zoonotic infections. The revised categories were expanded immunisation.17 quarantinable; vaccine preventable; gastrointestinal Children and adolescents in China have benefited and enteroviral; vectorborne; zoonotic; bacterial; greatly from overall reductions in infectious disea­ and sexually transmitted and bloodborne (see table ses during the past several decades, but rapid demo­ 1). Medical staff confirmed all patients with a clinical graphic, epidemiological, and nutritional transitions diagnosis by clinical standards and laboratory have brought a pressing need to track infectious tests based on national uniform standards (see diseases in children and adolescents.16 18 Children and supplementary appendix). Since 2014, H1N1 has been adolescents remain the most susceptible age group to included in the seasonal influenza category.19 Case most infectious diseases, which makes them a priority information recorded in CISDCP included time and for Chinese public health policy. Yet there has been no place of onset and death, diagnosed disease, age, sex, systematic study of the changing patterns of infectious and occupation. Case identification information (eg, diseases in China. With the objective of highlighting name, address) is not recorded to ensure confidentiality public health policy priorities, we analysed recent of data. trends across time and by age, sex, season, and province for 44 notifiable infectious diseases in Inclusion and exclusion criteria children and adolescents using web based surveillance Children and adolescents were included in the analysis CISDCP data from 2008 to 2017. if they were a student aged 6 to 22 years with verified http://www.bmj.com/ records of any of the 44 notifiable infectious diseases, Methods from 31 provinces in mainland China. According to Data collection Chinese law, “the free nine­year compulsory education Data were drawn from CISDCP. After the SARS outbreak system” law, introduced in 2006,20 school enrolment in 2003, China updated and established the web based is mandatory for children from age 6 years—that is, CISDCP to rapidly identify new cases and respond to parents or other legal guardians must send the children outbreaks. Since 2008 all case based data on notifiable to school during these years. Under the education infectious diseases are transmitted electronically to system in China, most 22 year olds have completed on 24 September 2021 by guest. Protected copyright. the China Centre for Disease Control (CDC) through undergraduate education. People were excluded direct online reporting. The system covers national from our analysis if they met any of the following notifiable infectious diseases for all 31 provinces in conditions1: were resident in Hong Kong, Macao, mainland China. We analysed data for the decade