Abstract:

Objective To analyze the epidemiological and pathogens characteristics of other infectious diarrhea in Heilongjiang Province for scientific evidence to formulate prevention and control measures. Methods Surveillance data on other infectious diarrhea and public health emergencies in Heilongjiang Province from January, 2005 to December, 2024 were retrieved from the Chinese Disease Prevention and Control Information System. Descriptive epidemiology was used to analyze the epidemiological characteristics by time, region and population as well as the pathogenic spectrum. Software Joinpoint was applied to calculate the average annual percent change (AAPC) for analyzing the trend of the infection. Results A total of 89 461 cases of other infectious diarrhea were reported in Heilongjiang Province from 2005 to 2024, with an average annual reported incidence rate of 12.06 per 100 000 population. The reported incidence showed a downward trend, with AAPC (95%CI) of -2.40% (-4.80% to -0.30%) (t=-2.26, P<0.05). The incidence peaked in 2007 (17.64 per 100 000 population) and was the lowest in 2022 (4.96 per 100 000 population). Two epidemic peaks were observed, during which the peak incidence gradually shifted from June-August in 2005-2012(13 034/39 291; 33.17%) to March-April in 2023-2024(2 129/6 704; 31.76%). There were significant differences in the reported incidence among different prefecture-level cities across the province. The top three cities in average annual incidence were Mudanjiang (26.90 per 100 000), Hegang (17.66 per 100 000), and Harbin (16.19 per 100 000). Of the reported cases, 52 717 were males and 36 744 females. Children under 5 years old accounted for the majority of cases (55 980/89 461; 62.57%), and individual children living at home were the predominant occupation group (55 533/89 461; 62.08%). A total of 3 419 cases had confirmed pathogens, including 3 362 viral infections (98.33%) and 57 bacterial infections (1.67%). Norovirus and rotavirus were the dominant pathogens, with 1 710 cases (50.01%) and 1 558 cases (45.57%), respectively. In total, 30 public health emergencies of other infectious diarrhea were reported from 2005 to 2024, all caused by norovirus, of which 28 (93.33%) occurred in schools/kindergartens. Conclusion The overall incidence of other infectious diarrhea in Heilongjiang Province showed a downward trend from 2005 to 2024. However, the proportion of cases among kindergarten children and students presented an upward trend. Comprehensive prevention and control measures should be strengthened in the key settings such as kindergartens and schools to reduce the risk of outbreaks.

Key words: Other infectious diarrhea, Epidemiological characteristics, Pathogens, Heilongjiang Province