The Center for Disease Control and Prevention of Guangdong Province, 160 Quxian Road, Dashi Street, Panyu District, Guagnzhou, Guangdong 511430, China.
Virol J. 2013 Jun 2;10:174. doi: 10.1186/1743-422X-10-174.
CHIKV is a mosquito-borne emerging pathogen that has a major health impact in humans in tropical zones around the globe. A new variant of the virus, E1-A226V caused a large outbreak in the Indian Ocean islands and India from 2004-2007. CHIKV outbreak was initially reported in Dongguan region of Guangdong in 2010 in China, another smaller CHIKV outbreak was found in Yangjiang region of Guangdong two weeks later. The viral agent causing the two outbreaks was inferred to be the new E1-A226V variant and Yangjiang CHIKV might be introduced from Dongguan. To confirm the hypothesis and determine the origin of CHIKV causing the outbreaks, we described Yangjiang outbreak in this study, and the molecular characterization of CHIKV from Yangjiang and Dongguang outbreaks were analyzed.
27 clinical cases of CHIK fever were reported in outbreak in Yangjiang region. Sera sample from 12 clinical cases were collected from the outbreak, and nucleic acid and antibody tests for CHIKV were performed 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 virus strains were isolated. Four viral genomes from Dongguan and Yangjiang were sequenced, characterized and phylogeneticly analyzed. Phylogenetic analysis revealed that the 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.
CHIKV with an E1-A226V mutation that originated from Southeast Asia isolates caused two outbreaks in China in 2010, and originated from two different infectious sources.
基孔肯雅热病毒（CHIKV）是一种通过蚊子传播的新兴病原体，对全球热带地区的人类健康造成重大影响。该病毒的一个新变体 E1-A226V 于 2004 年至 2007 年在印度洋岛屿和印度造成了一次大规模爆发。2010 年，中国广东省东莞市首次报告了基孔肯雅热疫情，两周后，广东省阳江市也发现了另一次较小规模的基孔肯雅热疫情。两次疫情的病毒病原体被推断为新型 E1-A226V 变体，阳江市的基孔肯雅热病毒可能是从东莞市传入的。为了证实这一假设并确定引发疫情的基孔肯雅热病毒的来源，我们在本研究中描述了阳江市的疫情，并对阳江市和东莞市疫情的基孔肯雅热病毒进行了分子特征分析。
阳江市疫情共报告 27 例基孔肯雅热病例。采集了 12 例临床病例的血清样本，采用实时 RT-PCR 和间接免疫荧光法进行基孔肯雅热病毒的核酸和抗体检测。对实时 RT-PCR 阳性样本进行病毒分离。结果显示，12 份样本中有 3 份实时 RT-PCR 阳性。7 份和 4 份样本分别对基孔肯雅热病毒的 IgM 和 IgG 呈阳性，分离出两种病毒株。对来自东莞和阳江的 4 株病毒基因组进行测序、特征分析和系统进化分析。系统进化分析显示，这 4 株分离株与属于印度洋分支的 2008 年新加坡分离株的亲缘关系最密切（99.4%~99.6%的同源性）。在这 4 株病毒中观察到 E1-A226V 位点的共同突变。在东莞和阳江疫情株的 CHIKV 序列中分别检测到 4 个和 3 个 aa 取代。
源自东南亚分离株的具有 E1-A226V 突变的基孔肯雅热病毒于 2010 年在中国引发了两次疫情，起源于两个不同的传染源。
