Objective To explore the epidemiological characteristics of Kala-azar disease in China from 2005 to 2015,to provide evidence for the development of related control and measurement strategies.Methods Data was obtained from Disease Reporting Information System of China CDC,to compare factors on type,distribution,peak season and the age of onset of the cases.Results Epidemic of Kala-azar had been persistent in China.Number of the reported cases declined in Sichuan and Gansu provinces but two outbreaks had occurred in Xinjiang Uygur autonomous region.The epidemic was confined in few areas.The reported cases were mainly from Xinjiang,Gansu and Sichuan,with the total cases in these three provinces accounted for 95.29％ of all the cases seen in the country.The main peak season was from October to November,followed by April.There were significant differences seen in the age distributions of canine Kala-azar,anthroponotic Kala-azar and wildlife-oriented Kala-azar (P＜0.05) cases.Majority of the cases involved under 3-year-olds,with peak age in under 1-year-olds for wildlife-oriented Kala-azar.For anthroponotic and canine Kala-azar cases,most of them were seen among the under 10 years old,with the peak among the 5-year-olds.Conclusions In recent years,Kala-azar had been seen endemic and persistent,in the mid-west regions of China,but with different epidemiological characteristics.Further study on Kala-azar should be carried on to include appropriate measurements and strategies,according to the features of the disease,in the mid-western areas of China.

Objective To investigate the feasibility of constructing the risk index of Echinococcus infection based on the classification of echinococcosis lesions, so as to provide insights into the management of echinococcosis. Methods The imaging data of echinococcosis cases were collected from epidemiological surveys of echinococcosis in China from 2012 to 2016, and the detection of incident echinococcosis cases was captured from the annual echinococcosis prevention and control reports across provinces (autonomous regions) and Xinjiang Production and Construction Corps in China from 2017 to 2022. After echinococcosis lesions were classified, a risk index of Echinococcus infection was constructed based on the principle of discrete distribution marginal probability and multi-group classification data tests. The correlation between the risk index of Echinococcus infection and the detection of incident echinococcosis cases was evaluated in the provinces (autonomous regions and corps) from 2017 to 2022, and the correlations between the short and medium-term risk indices and between the medium and long-term risk indices of Echinococcus infection were examined using a univariate linear regression model. Results A total of 4 014 echinococcosis cases in China from 2012 to 2016 were included in this study. The short-, medium- and long-term risk indices of E. granulosus infection varied in echinococcosis-endemic provinces (autonomous regions and corps) of China (χ² = 4.12 to 708.65, all P values < 0.05), with high short- (0.058), medium- (0.137) and long-term risk indices (0.104) in Tibet Autonomous Region, and the short-, medium- and long-term risk indices of E. multilocularis infection varied in echinococcosis-endemic provinces (autonomous regions and corps) of China (χ² = 6.74 to 122.60, all P values < 0.05), with a high short-term risk index in Sichuan Province (0.016) and high medium- (0.009) and long-term risk indices in Qinghai Province (0.018). There were no significant correlations between the risk index of E. granulosus infection and the detection of incident cystic echinococcosis cases during the study period (t = −0.518 to 2.265, all P values > 0.05), and strong correlations were found between the risk indices of E. multilocularis infection and the detection of incident alveolar echinococcosis cases (including mixed type) in 2018, 2020, 2021, 2022, during the period from 2017 through 2020, from 2017 through 2021, from 2017 through 2022 (all r values > 0.7, t = 2.521 to 3.692, all P values < 0.05). Linear regression models were established between the risk index of E. multilocular infection and the detection of alveolar echinococcosis cases (including mixed type), and the models were all statistically significant (b = 0.214 to 2.168, t = 2.458 to 3.692, F = 6.044 to 13.629, all P values < 0.05). The regression coefficients for the correlations between the medium- and short-term, and between the long- and medium-term risk indices of E. granulosus infection were 2.339 and 0.765, and the regression coefficients for the correlations between the medium- and short-term, and between the long- and medium-term risk indices of E. multilocular infection were 0.280 and 1.842, with statistical significance seen in both the regression coefficients and regression models (t = 16.479 to 197.304, F = 271.570 to 38 928.860, all P values < 0.05). Conclusions The risk index of Echinococcus infection has been successfully established based on the classification of echinococcosis lesions, which may provide insights into the prevention and control, prediction, diagnosis and treatment, and classified management of echinococcosis.