Epidemiological characteristics of hemorrhagic fever with renal syndrome in Qiqihar City, Heilongjiang Province from 2016 to 2020 / 中华地方病学杂志

ABSTRACT

Objective:To analyze the epidemiological characteristics of hemorrhagic fever with renal syndrome (HFRS) in Qiqihar City, and to understand the epidemic and development rules of HFRS, and to provide scientific basis for formulating targeted prevention and control measures.Methods:The data of HFRS cases in Qiqihar City from 2016 to 2020 were collected from the China Disease Control and Prevention Information System by retrospective analysis, and the three distributions (time, region and population distribution) of HFRS were analyzed by descriptive epidemiology. At the same time, the monitoring data of rats in Nehe City from 2016 to 2020 were collected from the Nehe Municipal Center for Disease Control and Prevention for descriptive analysis.Results:From 2016 to 2020, 868 HFRS cases were reported in Qiqihar City, with 10 deaths. The average annual incidence rate was 3.26/100 000, the average annual mortality rate was 0.04/100 000, and the case fatality rate was 1.15%. From 2016 to2020, the incidence rates were 3.23/100 000, 3.31/100 000, 3.22/100 000, 4.10/100 000 and 2.43/100 000, respectively. Incidence occurred in all months of the year, with the peak period from October to December (490 cases in total). The top five counties(cities) with the incidence of HFRS were Nehe City (7.46/100 000), Keshan County (5.03/100 000), Gannan County (3.84/100 000), Fuyu County (3.82/100 000) and Tailai County (3.63/100 000). Among the patients, 76.04% (660/868) were male and 23.96% (208/868) were female; the age of onset was mainly 30-69 years old, accounting for 81.57% (708/868) of the total cases; the occupation distribution was mainly farmers, accounting for 75.46% (655/868) of the total cases. The results of rat monitoring in Nehe City from 2016 to 2020 showed that Rattus norvegicus was the dominant species in the field and village, accounting for 65.13% (581/892) and 80.21% (466/581), respectively. In spring, the rat density in the field and village was 3.37% (397/11 771) and 6.64% (275/4 141), respectively; in autumn, the rat density in the field and village was 8.47% (495/5 843) and 9.40% (306/3 254), respectively. The virus carrying rate of Rattus norvegicus was high, 13.14% (131/997); the infection rate of Rattus norvegicus was also high, 15.15% (151/997); the virus carrying rate and infection rate in the village were higher than those in the field (χ 2 = 6.87, P = 0.009; χ 2 = 13.05, P < 0.001). Conclusions:The incidence of HFRS in Qiqihar City is relatively stable from 2016 to 2018, rising in 2019 and falling back in 2020; the onset time is mainly in autumn and winter, mainly male and farmers. From 2016 to 2020, among all counties (cities, districts) in Qiqihar City, the incidence of HFRS in Nehe City is high, and the density of rats in autumn is higher than that in spring. Rattus norvegicus is the main species of rats, with high virus carrying rate and infection rate.