Chen, Li, Xing, Yi, Zhang, Yi, Xie, Junqing, Su, Binbin, Jiang, Jianuo, Geng, Mengjie, Ren, Xiang, Guo, Tongjun, Yuan, Wen, Ma, Qi, Chen, Manman, Cui, Mengjie, Liu, Jieyu, Song, Yi, Wang, Liping, Dong, Yanhui, and Ma, Jun
Background: An accelerated epidemiological transition, spurred by economic development and urbanization, has led to a rapid transformation of the disease spectrum. However, this transition has resulted in a divergent change in the burden of infectious diseases between urban and rural areas. The objective of our study was to evaluate the long-term urban–rural disparities in infectious diseases among children, adolescents, and youths in China, while also examining the specific diseases driving these disparities. Methods and findings: This observational study examined data on 43 notifiable infectious diseases from 8,442,956 cases from individuals aged 4 to 24 years, with 4,487,043 cases in urban areas and 3,955,913 in rural areas. The data from 2013 to 2021 were obtained from China's Notifiable Infectious Disease Surveillance System. The 43 infectious diseases were categorized into 7 categories: vaccine-preventable, bacterial, gastrointestinal and enterovirus, sexually transmitted and bloodborne, vectorborne, zoonotic, and quarantinable diseases. The calculation of infectious disease incidence was stratified by urban and rural areas. We used the index of incidence rate ratio (IRR), calculated by dividing the urban incidence rate by the rural incidence rate for each disease category, to assess the urban–rural disparity. During the nine-year study period, most notifiable infectious diseases in both urban and rural areas exhibited either a decreased or stable pattern. However, a significant and progressively widening urban–rural disparity in notifiable infectious diseases was observed. Children, adolescents, and youths in urban areas experienced a higher average yearly incidence compared to their rural counterparts, with rates of 439 per 100,000 compared to 211 per 100,000, respectively (IRR: 2.078, 95% CI [2.075, 2.081]; p < 0.001). From 2013 to 2021, this disparity was primarily driven by higher incidences of pertussis (IRR: 1.782, 95% CI [1.705, 1.862]; p < 0.001) and seasonal influenza (IRR: 3.213, 95% CI [3.205, 3.220]; p < 0.001) among vaccine-preventable diseases, tuberculosis (IRR: 1.011, 95% CI [1.006, 1.015]; p < 0.001), and scarlet fever (IRR: 2.942, 95% CI [2.918, 2.966]; p < 0.001) among bacterial diseases, infectious diarrhea (IRR: 1.932, 95% CI [1.924, 1.939]; p < 0.001), and hand, foot, and mouth disease (IRR: 2.501, 95% CI [2.491, 2.510]; p < 0.001) among gastrointestinal and enterovirus diseases, dengue (IRR: 11.952, 95% CI [11.313, 12.628]; p < 0.001) among vectorborne diseases, and 4 sexually transmitted and bloodborne diseases (syphilis: IRR 1.743, 95% CI [1.731, 1.755], p < 0.001; gonorrhea: IRR 2.658, 95% CI [2.635, 2.682], p < 0.001; HIV/AIDS: IRR 2.269, 95% CI [2.239, 2.299], p < 0.001; hepatitis C: IRR 1.540, 95% CI [1.506, 1.575], p < 0.001), but was partially offset by lower incidences of most zoonotic and quarantinable diseases in urban areas (for example, brucellosis among zoonotic: IRR 0.516, 95% CI [0.498, 0.534], p < 0.001; hemorrhagic fever among quarantinable: IRR 0.930, 95% CI [0.881, 0.981], p = 0.008). Additionally, the overall urban–rural disparity was particularly pronounced in the middle (IRR: 1.704, 95% CI [1.699, 1.708]; p < 0.001) and northeastern regions (IRR: 1.713, 95% CI [1.700, 1.726]; p < 0.001) of China. A primary limitation of our study is that the incidence was calculated based on annual average population data without accounting for population mobility. Conclusions: A significant urban–rural disparity in notifiable infectious diseases among children, adolescents, and youths was evident from our study. The burden in urban areas exceeded that in rural areas by more than 2-fold, and this gap appears to be widening, particularly influenced by tuberculosis, scarlet fever, infectious diarrhea, and typhus. These findings underscore the urgent need for interventions to mitigate infectious diseases and address the growing urban–rural disparity. Li Chen, Yi Xing, and colleagues examine the long-term urban-rural disparities in 43 infectious diseases among children, adolescents, and youths in China. Author summary: Why was this study done?: ➢ Despite national health priorities and immunization programs, the urban–rural disparity in infectious diseases in children and adolescents is often overlooked. ➢ To our knowledge, while some studies have evaluated infectious diseases burdens in children, adolescents, and youths, none have conducted a comprehensive comparison of disease patterns between urban and rural areas in China or other countries. What did the researchers do and find?: ➢ We used the incident cases of infectious diseases aged 4 to 24 years old from China to study the urban–rural disparity in infectious diseases and its long-term change over time. ➢ The burden of infectious diseases in urban areas was more than double that of rural areas, and this disparity widened over time, particularly for tuberculosis and scarlet fever among vaccine-preventable diseases, and infectious diarrhea among gastrointestinal and enterovirus diseases. ➢ Among Chinese youth, overall infectious diseases were unequally distributed, with vaccine-preventable diseases showing the highest inequality. What do these findings mean?: ➢ The substantial burden of infectious diseases in urban areas, underscores the unique health challenges faced by urban populations. ➢ The urban–rural disparities and inequality underscore the need for nuanced strategies in addressing infectious diseases, influenced by factors like socioeconomic development and urbanization, across diverse disease types and geographical contexts. ➢ Study limitations involve using annual average population data without considering population mobility for incidence calculations. [ABSTRACT FROM AUTHOR]