Background: The re-emergence of dengue virus 4 (DENV-4) has become a public health concern in South\r\nAmerica, Southeast Asia and South Asia. However, it has not been known to have caused a local outbreak in China\r\nfor the past 20 years. The purpose of this study was to elucidate the epidemiology of one local community\r\noutbreak caused by DENV-4 in Guangzhou city, China, in 2010; and to determine the molecular characteristics of\r\nthe genotype II virus involved.\r\nCase presentations: During September and October of 2010, one imported case, a Guangzhou resident who\r\ntravelled back from Thailand, resulted in 18 secondary autochthonous cases in Guangzhou City, with an incidence\r\nrate of 5.53 per 10,000 residents. In indigenous cases, 14 serum samples tested positive for IgM against DENV and\r\n7 for IgG from a total of 15 submitted serum samples, accompanied by 5 DENV-4 isolates. With identical envelope\r\ngene nucleotide sequences, the two isolates (D10168-GZ from the imported index case and Guangzhou 10660\r\nfrom the first isolate in the autochthonous cases) were grouped into DENV-4 genotype II after comparison to 32\r\nprevious DENV-4 isolates from GenBank that originated from different areas.\r\nConclusions: Based on epidemiological and phylogenetic analyses, the outbreak, which was absent for 20 years\r\nafter the DENV-4 genotype I outbreak in 1990, was confirmed as DENV-4 genotype II and initially traced to the\r\nimported index case, a Guangzhou resident who travelled back from Thailand.
Loading....