Molecular analysis of the first dengue fever case in Dapeng New District of Shenzhen City / 上海预防医学

Objective:To analyze the first suspected dengue fever case in Dapeng New District by characterizing the virus and exploring its origin. Methods:Dengue virus nucleic acid in blood sample was identified by real-time fluorescent RT-PCR. The E gene of dengue virus was amplified and sequenced. Homology and phylogenetic tree of this dengue virus were compared with the isolates from other regions. Results:Nucleic acid of dengue virus type 1 was detected in the serum sample from the suspected dengue fever patient. Phylogenetic tree showed that the homology based on nucleotide sequence of E gene of DP-DGR19001 was very similar with the isolates of MG894965/TW/CHN/2016 （99.87%）， LC428079/VNM/2017（99.80%）， MG894867/TW/CHN/2015 （99.60%） and MN512242/GX/CHN/2014 （99.46%）. The deduced amino acid sequence of 5 isolates was 100% identical. The patient had traveled to high-incidence country Cambodia in 14 days before infection. Conclusions:The first suspected dengue fever case in Dapeng New District is caused by dengue virus type 1. The case is an imported dengue fever .

Surveillance of antibody level of influenza among physical examination population of Shenzhen City from 2014 to 2018 / 上海预防医学

Objective To provide the basis for influenza epidemic prevention and control by monitoring the antibody level of influenza among the general population in Dapeng New District of Shenzhen City. Methods A total of 1 350 serum samples of people were collected ten times from 2014 to 2018, and the antibody level was tested by hemagglutination-inhibition test. Results During 2014-2018 years, only the positive rate of antibody to H3N2 was above 60%.The positive rates of H1N1, H3N2, BV and BY were 50.0%, 85.6%, 35.4% and 45.6%, respectively, and the geometric mean titers (GMT) of antibody were 8.2, 81.5, 3.9 and 6.4, respectively.Influenza antibody titers of 1 : 160 and 1 : 320 were mainly distributed in influenza H3N2.The antibody level of BV and BY in age group 0~4 years was 29.0% and 30.4% separately. Conclusion It is imperative to enhance the surveillance of antibody level of influenza among general population in Dapeng New District, to investigate the epidemic development trend of influenza constantly, and to prevent and control the outbreak of influenza epidemics.