Srikanth P, Sarangan G, Mallilankaraman K, Nayar S A, Barani R, Mattew T, Selvaraj G F, Sheriff K A, Palani G, Muthumani K
Department of Microbiology, Sri Ramachandra Medical College and Research Institute, Sri Ramachandra University, Chennai, Tamil Nadu, India.
Indian J Med Microbiol. 2010 Oct-Dec;28(4):299-302. doi: 10.4103/0255-0857.71812.
Re-emergence of Chikungunya is a major public health problem in the southern states of India.
This study was undertaken to investigate an outbreak of Chikungunya, in June-August 2008 using PCR and determine the prevalent genotypes of Chikungunya virus (CHIKV) associated with the outbreak.
Samples of blood were collected (in heparinized vacutainer tubes) from suspected patients of CHIKV infection from both Government Taluk Hospital in Kerala and a tertiary care hospital in Chennai, Tamil Nadu. A one-step RT-PCR was carried out on a block thermo-cycler targeting the E2 gene that codes for the viral envelope protein. The amplicons were verified for 305 bp size by standard agarose gel electrophoresis. The PCR products were purified, sequenced, and compared with other CHIKV strains reported from different geographical regions. A phylogenetic tree was constructed using MEGA 4.
Altogether 118 samples were collected from patients who presented with sudden onset of fever and/or joint pain, myalgia, and headache. CHIKV infection was confirmed by RT-PCR in 14 patients and all these cases were from Kerala. The positivity correlated with the early stage of the disease as all these patients had fever of less than seven days duration. The study isolates have been allotted the GenBank accession nos. GQ272368-GQ272381. Phylogenetic analysis of recent CHIKV isolates by partial sequencing of E2 region shows that isolates are closely related to strains from neighboring states and the African type.
RT-PCR is a useful technique for the early detection of CHIKV infection during outbreaks. Molecular characterization of the strains indicates that majority of the strains have originated from the Central/East African strains of CHIKV.
基孔肯雅热的再度出现是印度南部各邦的一个主要公共卫生问题。
本研究旨在利用聚合酶链反应（PCR）调查2008年6月至8月间基孔肯雅热的一次疫情爆发，并确定与该疫情相关的基孔肯雅病毒（CHIKV）流行基因型。
从喀拉拉邦政府Taluk医院和泰米尔纳德邦金奈的一家三级护理医院的基孔肯雅病毒感染疑似患者中采集血液样本（置于肝素抗凝真空管中）。在一个模块式热循环仪上进行一步法逆转录聚合酶链反应（RT-PCR），以靶向编码病毒包膜蛋白的E2基因。通过标准琼脂糖凝胶电泳验证扩增产物的大小为305 bp。对PCR产物进行纯化、测序，并与不同地理区域报告的其他基孔肯雅病毒株进行比较。使用MEGA 4构建系统发育树。
共从出现突发发热和/或关节疼痛、肌痛及头痛的患者中采集了118份样本。通过RT-PCR在14名患者中确诊了基孔肯雅病毒感染，所有这些病例均来自喀拉拉邦。阳性结果与疾病早期相关，因为所有这些患者的发热持续时间均不到7天。该研究分离株已被赋予GenBank登录号GQ272368 - GQ272381。通过对E2区域进行部分测序对近期基孔肯雅病毒分离株进行的系统发育分析表明，分离株与来自邻国的毒株及非洲型毒株密切相关。
RT-PCR是疫情爆发期间早期检测基孔肯雅病毒感染的一种有用技术。毒株的分子特征表明，大多数毒株源自基孔肯雅病毒的中非/东非毒株。
