GenBank Accession numbers are given in parentheses

GenBank Accession numbers are given in parentheses. Four and three common amino acid residue changes were observed in polyproteins within the two isolates from Dongguan and Yangjiang compared to the Singapore isolate (“type”:”entrez-nucleotide”,”attrs”:”text”:”FJ445484″,”term_id”:”288572713″,”term_text”:”FJ445484″FJ445484) respectively. using Real-time RT-PCR and indirect immunofluorescence. Positive samples of Real-time RT-PCR were subjected to viral isolation. The results showed 3/12 samples positive for Real-time RT-PCR. 7/12 and 4/12 samples were positive for IgM and IgG against CHIKV respectively, two Flufenamic acid computer virus strains were isolated. Four viral genomes from Dongguan and Yangjiang were sequenced, characterized and phylogeneticly analyzed. Phylogenetic analysis revealed that this four seqeunced viruses had the closest relationship (99.4~99.6% identify) with the Singapore 2008 isolate belonging to the Indian ocean clade. A common mutation at the site of the E1-A226V was observed among four viruses. Four and three aa substitutions were detected in the CHIKV sequence from the Dongguan and Yangjiang outbreak strains respectively. Conclusion CHIKV with an E1-A226V mutation that originated from Southeast Asia isolates caused two outbreaks in China in 2010 2010, and originated from two different infectious sources. mosquitoes [1]. Human infections caused by Chikungunya virus were reported for the first IgM Isotype Control antibody (PE-Cy5) time in East Africa in 1952C53 during an epidemic of fever that developed along the border between Tanzania and Mozambique [2]. Retrospective case reviews have suggested that CHIKV epidemics occurred as early as 1779 but were frequently documented inaccurately as dengue outbreaks [3]. Between the 1960s and 1990s, the virus was isolated repeatedly from numerous countries in Central, Southern and Western Africa [4]. In Southeast Asia, the first outbreak was reported in Bangkok in 1958 [5] followed by frequent outbreaks in India [6], Indonesia [7], Myanmar [8], Malaysia [9], Singapore [10], Thailand [11], Cambodia [12] and Vietnam [13]. However, no outbreak due to the local transmission of CHIKV was reported in China before 2010. Mutations in CHIKV, climate change, increasing globalization, and increasing ease of travel have favored the continuing spread of mosquitoes to non-indigenous habitats [4,14]. The new E1-A226V variant enhanced the replication and dissemination of CHIKV in mosquitoes and evaluate the risk of dengue-virus transmission in Guangdong, the Breteau index (BI) has been used as a mosquito density investigation tool for many years. BI is defined as number of positive containers for per 100 houses. BI was investigated for one month after the two CHIKV outbreaks were confirmed in two communities as well as their neighbor communities. No Flufenamic acid were found during monitoring, and was found to be the predominant species. An average BI of 126 was observed in the Huahong communities before control Flufenamic acid measures were implemented. The BI began to notably decrease after control measures were implemented. Average BI after control measures was implemented were found to be 2.1 in the Huahong communities. Sample collection and IgM and IgG detection A total of 12 sera samples were collected from patients between the ages of 32C70 years with dengue-like symptoms in the outbreak. The patients were comprised of 8 males and 4 females. Five of 12 samples were collected during the acute phase (1C9 days after onset of symptoms) and 7 of the 12 samples were collected during the convalescent phase (10C28 days after onset of symptoms). For serologic diagnosis, these 12 samples were subjected to an indirect immunofluorescence test (IIFT) and an enzyme linked immunosorbent assay (ELISA) for CHIKV and Dengue virus IgM and IgG antibody respectively. The results proved that 7 and 4 samples were positive for CHIKV IgM and IgG respectively. All of the sera were negative for dengue IgM and IgG antibodies. Real-time RT-PCR and virus isolation In order to diagnose the suspected cases at the nucleic acid level, improve the CHIKV isolation rate, and reduce labor intention, 12 samples collected from the Yangjiang outbreaks were subjected to Real-time RT-PCR (Table?1). The results showed that 3 samples collected.