Molecular tracing of pathogen of the first local dengue fever case in Hangzhou

Objective To understand the pathogen's molecular characteristics of the first local dengue fever case in Hangzhou. Methods The epidemiological survey was conducted and the serum sample was collected from the dengue fever patient to detect dengue virus nucleic acids and antibody. The envelope(E) gene of the viruswas amplified and sequenced. The genotype of the isolate was analyzed with bioinformatics software. Results The serum sample of the patient was positive for dengue virus nucleic acids and anti-dengue IgM.The homologous and phylogenetic analysis showed that the isolate belonged to dengue virus type 1 and the sub genotype was GⅣ. It had a closest phylogenetic relationship with the strain isolated from the case imported from the Philippines in Korea in 2007, sharing 98.9% and 99.6% homology in nucleotide sequence and amino acid sequence respectively; and the strain isolated shared 98.6% and 99.6% homology in sequences of nucleotide and amino acid respectively with the strain isolated from the Philippines in 2010, indicating that it might originated from the Philippines. Conclusion The first local dengue fever case in Hangzhou might be caused by the imported case who returned from Philippines after the travel in this country.