Abstract: Objective To explore the epidemic of dengue fever and analyze the genotype of dengue virus serotgpe Ⅰ （DENV-1） and characteristic of E gene in Dongguan from 2014 to 2019. Methods A total of 962 serum samples of clinically diagnosed suspected dengue fever cases were collected from various town and street hospitals in Dongguan from 2014 to 2019. The level of IgM antibody of 729 serum samples were detected by enzyme-linked immunosorbent assay （ELISA）. All 962 serum samples were detected by real time PCR method. DENV-1 samples in nucleic acid positive samples were isolated and identified by cell culture, and their E gene sequences were sequenced and phylogenetic tree analysis was carried out. Results From 2014 to 2019, dengue fever in Dongguan was prevalent from July to November and peaked from September to October. Two hundred and sixty-one samples of IgM antibody positive were detected, and the positive rate was 35.90%. Three hundred and sixty-two samples were positive for DENV nucleic acid. Among the positive samples, 311 were DENV-1 positive, accounting for 85.9%, and 35 strains of DENV-1 were isolated. Sequence alignment and evolutionary of Egene analysis showed that the nucleotide homology among the 35 strains of DENV-1 was 89.8%-100.0%. They were genotype Ⅰ （29 strains）, genotype Ⅱ （1 strain） and genotype Ⅴ （5 strains）. The 35 strains had higher homology with strains from Guangzhou and Zhejiang and the southeast Asian countries such as Viet Nam and Philippines and India. Conclusions The dominant type of dengue virus circulating in Dongguan during 2014-2019 is genotype Ⅰ DENV-1. The epidemic mode of dengue fever may be local outbreaks caused by imported cases mainly from the cities in or around Guangzhou and southeast Asian countries. We must be wary of the imported genotype Ⅴ DENV-1 that causes dengue fever outbreak.

Key words: DENV-1, ELISA, E gene, Similarity, Evolutionary analysis