Investigation and analysis of an outbreak of dengue fever in Jishou city,Hunan province in 2023
Objective To analyze the epidemiological characteristics of dengue fever outbreak in Jishou city,Hunan province in 2023,and provide reference for the prevention and control of local dengue fever outbreak in the future.Methods Case search,epidemiological investigation and vector Aedes mosquito surveillance of dengue fever were conducted in all medical facilities and designated epidemic zones in Jishou city in September to October 2023.Biosamples of cases were also collected for laboratory testing to assess the epidemic situation and its influencing factors.Results The first case of dengue fever outbreak occurred on September 11,2023,and the last case occurred on September 30,2023.The outbreak ended on October 28 and lasted for 47 days.A total of 47 cases of dengue fever were reported,of which 45 cases were confirmed,2 cases were clinically diagnosed,and there were no severe cases or deaths.The reported attack rate was 1.88/100 000.The epidemic curve showed a proliferative pattern of human-to-human transmission.The cases were distributed in 5 streets and 15 communities in the city,mainly in Qianzhou street and Shijiachong street.The sex ratio of male to female was 1∶1.24.Occupation distribution shows that farmers,retirees,unit workers and commercial service personnel were the majorities,accounted for 29.79％,17.02％,12.77％,12.77％.All the 47 cases denied that they had a history of going out and traveling in epidemic areas,and all of them had a history of mosquito bites in Jishou city.The interval between onset and diagnosis was 0-12 days,with a median of 4 days,and 42.55％of the patients were ≥ 4 days.The interval between the onset of the first case and the discovery of the epidemic situation was 12 days.Daily emergency surveillance of Aedes mosquito was carried out in the designated core area and warning area;the comprehensive Breitu index in Jishou city decreased from 81.8 on September 27 to 1.69 on October 12.Laboratory tests showed that 95.74％of the cases(45/47)were positive for NS1 antigen and nucleic acid,and the virus was DENV-1 serotype.Conclusions This outbreak might be local transmission caused by imported cases of dengue fever or recessive infection.It was suggested that the diagnosis level of dengue fever in medical institutions should be strengthened,the sensitivity of dengue fever surveillance should be improved,and the external environment control and mosquito vector density surveillance should be strengthened to ensure that the epidemic could be detected and controlled promptly.
万方数据
维普
