Objective:To study the epidemic characteristics of kala-azar in Shaanxi Province, and to provide scientific basis for formulating effective prevention and control measures.Methods:Information of kala-azar confirmed cases and clinically diagnosed cases whose current addresses were reported in Shaanxi Province in the Surveillance Report Management System of China Disease Control and Prevention Information System from 2011 to 2022 was collected. Trend analysis was made on the number of cases in each year, and descriptive epidemiological methods were used to analyze the onset time, regional and population distribution characteristics and the time interval from onset to diagnosis of kala-azar cases.Results:A total of 225 kala-azar cases were reported in Shaanxi Province from 2011 to 2022, and the number of cases showed an increasing trend (χ 2trend = 98.50, P < 0.001), with the highest number in 2020 (42 cases). The onset time was mainly from March to May (77 cases, 34.22%). The top three cities with the number of reported cases were Hancheng (65 cases, 28.89%), Shangluo (47 cases, 20.89%) and Weinan cities (44 cases, 19.56%). The male to female ratio was 1.74∶1.00 (143/82), the age of onset was mainly concentrated in the age group of 36 - 60 years old (111 cases, 49.33%), and the occupation was mainly farmers (150 cases, 66.67%). The median interval from onset to diagnosis was 11 days, and 78.22% (176/225) of the cases were diagnosed within 1 month. Conclusions:From 2011 to 2022, the overall incidence of kala-azar in Shaanxi Province has showed an upward trend, with the main population being middle-aged male farmers. The main affected areas are Hancheng, Shangluo and Weinan cities. It is urgent to strengthen the surveillance and prevention and control of kala-azar in key populations and key regions.

【Objective】 To assess the epidemiological characteristics and transmission risk of asymptomatic COVID-19 infection in Shaanxi Province. 【Methods】 A dense population database of COVID-19 cases in Shaanxi Province was constructed as of March 26, 2020, and 28 asymptomatic infected patients were selected through case epidemiological investigation report for descriptive analysis. 【Results】 In Shaanxi Province, the majority of asymptomatic COVID-19 infections were in the 20-59 years old group, and women took up a higher proportion than men. 82.14% of asymptomatic infections were found in the centralized isolation state. Nearly 80% of asymptomatic infections and confirmed cases were mainly exposed by living together in the family. The median number of days from last contact with the source of infection for all asymptomatic infected persons was 13, with 3 (10.71%) showing clinical symptoms. Epidemiological investigations showed that asymptomatic infections could spread as a result of shared family life. 【Conclusion】 At present, imported cases in Shaanxi Province continue to exist. Considering the concealed transmission of asymptomatic infections, prevention and control work is still facing challenges.