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Objective:To understand the influencing factors of death of epidemic Japanese encephalitis (EJE) cases in Longnan City of Gansu Province.Methods:In the EJE Monitoring Information Report Management System of the Chinese Disease Prevention and Control Information System, data on EJE cases with onset from 2014 to 2018 and current address in Longnan City were derived. An "Individual Questionnaire of Epidemic Japanese Encephalitis in Longnan City" was designed, retrospective study was conducted on enrolled cases, their information on demographic data, consultation, onset, clinical classification, and chronic underlying diseases were collected, characteristics of EJE cases and death-related factors were analyzed.Results:From 2014 to 2018, a total of 260 EJE cases were reported in Longnan City, and 259 cases completed the questionnaire. Among them, 70 cases (27.0%) were aged ≥60 years old, 67 cases (25.9%) were severe and extremely severe, and 55 cases (21.2%) had chronic underlying diseases. Among 259 EJE cases, 46 cases died, with a fatality rate of 17.8%. After multivariate unconditional logistic regression analysis, age ≥60 years old [odds ratio ( OR)=2.667, 95% confidence interval ( CI): 1.140-6.237], severe and extremely severe ( OR = 2.762, 61.820, 95% CI: 1.053-7.091, 5.149-742.239), and chronic underlying diseases ( OR = 2.489, 95% CI: 1.038-5.964) were risk factors for death in EJE cases. Conclusions:The influencing factors of death of EJE cases in Longnan City are age, clinical classification and chronic underlying diseases. Therefore, we should focus on patients over 60 years old, clinically classified as severe or extremely severe, and suffering from chronic underlying diseases, and strengthen the immunization of EJE vaccine for key populations.
RESUMEN
Objective:To understand the epidemic characteristics of epidemic Japanese encephalitis and the antibody level of healthy people in Longnan City, Gansu Province, analyze and evaluate its epidemic risk, and provide scientific basis for future prevention and control of Japanese encephalitis.Methods:By retrospective analysis, the data of Japanese encephalitis cases in Longnan City from 2015 to 2020 were collected from the "Japanese Encephalitis Monitoring Information Report Management System" of the "China Disease Prevention and Control Information System", and the distributions of the cases(time, region and population distribution) were statistically described and analyzed. In 2018, the cluster stratified sampling method was adopted to select Li County and Xihe County with higher incidence rate of Japanese encephalitis in Longnan City, and Wudu District and Hui County with lower incidence rate as monitoring sites, and 3 administrative villages (communities) were selected from each monitoring site to collect blood samples from healthy people to detect the level of Japanese encephalitis IgG antibodies.Results:From 2015 to 2020, a total of 261 cases of Japanese encephalitis were reported in Longnan City, with an average annual incidence of 1.66 per 100 000; among them, the number of reported cases in 2017 and 2018 accounted for 82.38% (215/261) of the total number of cases. The incidence of Japanese encephalitis was mainly concentrated in August, accounting for 72.03% (188/261); 9 counties (districts) in Longnan City had reported cases of Japanese encephalitis, and the top 5 counties (districts) with the number of cases were Li County (68 cases), Xihe County (64 cases), Wudu District (40 cases), Kang County (33 cases) and Cheng County (18 cases), accounting for 85.44% (223/261) of the total number of cases. The age of onset of Japanese encephalitis cases was mainly concentrated in the 40 - < 60 years old, accounting for 40.23% (105/261); male to female ratio was 1.00 ∶ 1.14 (122 ∶ 139); the occupation was mainly farmers, accounting for 75.86% (198/261). A total of 887 sera samples from healthy people were tested, and the antibody positive rate was 91.09% (808/887); the difference in antibody positive rate of different age groups was statistically significant (χ 2 = 5.77, P < 0.05); the differences of positive rate of antibodies between different genders and regions were not statistically significant (χ 2 = 0.45, 2.06, P > 0.05). Conclusions:The incidence of Japanese encephalitis in Longnan City is mainly middle-aged farmers, with a high incidence in August each year. After the outbreak of Japanese encephalitis in Longnan City in 2017 and 2018, it has showed a low epidemic trend, and the positive rate of Japanese encephalitis antibody in healthy people is high. It is recommended to carry out regular monitoring of Japanese encephalitis immunization level of healthy people and strengthen the immunization of key populations in time.