Shandong Provincial Key Laboratory of Infectious Disease Control and Prevention, Shandong Center for Disease Control and Prevention, Jinan, People's Republic of China.
Appl Environ Microbiol. 2012 Oct;78(19):6946-53. doi: 10.1128/AEM.01861-12. Epub 2012 Jul 27.
Environmental surveillance is an effective approach in investigating circulating enteroviruses and had been conducted in the cities of Jinan and Linyi since February 2008 and April 2010, respectively. This study analyzed 46 sewage samples collected in the two cities in 2011 and found that echovirus 6 (E6) was the predominant serotype, with 134 isolates (65 in Jinan and 69 in Linyi) from 23 (50%) samples. This differs from the 2010 data that found 29 E6 isolates in Jinan and only 3 in Linyi. Phylogenetic analysis of the VP1 coding region showed that all environmental E6 samples from 2008 to 2011 (n = 167) segregated into two lineages and revealed an increase in VP1 gene diversity in 2011, suggesting that the increased number of E6 detections reflects a real epidemic in the two cities. Most Linyi isolates (n = 61, or 88%) in 2011 segregated into sublineage 1a, together with 18 Jinan isolates in 2011. Interestingly, the ancestral VP1 sequence of sublineage 1a inferred using the maximum-likelihood method had 100% identity with the sequence of one environmental isolate from Jinan in August 2010, suggesting an intercity spread from Jinan to Linyi. By Bayesian phylodynamic methods, the most recent common ancestor of Linyi isolates in sublineage 1a dated back to 24 December 2010, revealing that this sublineage was likely imported into Linyi from August to December in 2010. This study demonstrates that environmental surveillance is a sensitive method in tracing transmission pathways of circulating enteroviruses among different regions and reveals that E6-associated aseptic meningitis is an emerging concern in China.
环境监测是调查循环肠道病毒的有效方法，自 2008 年 2 月和 2010 年 4 月以来，分别在济南市和临沂市开展了此项监测。本研究分析了 2011 年从这两个城市采集的 46 份污水样本，发现肠道病毒 6 型（E6）是主要血清型，23 份（50%）样本中分离出 134 株（济南 65 株，临沂 69 株）。这与 2010 年的数据不同，当时在济南分离出 29 株 E6，而在临沂仅分离出 3 株。VP1 编码区的系统进化分析显示，2008 年至 2011 年所有环境 E6 样本（n = 167）分为两个分支，2011 年 VP1 基因多样性增加，表明 E6 检出数量的增加反映了这两个城市的真实疫情。2011 年，大多数临沂分离株（n = 61，占 88%）分为亚组 1a，与 2011 年的 18 株济南分离株一起。有趣的是，使用最大似然法推断的亚组 1a 的祖先 VP1 序列与 2010 年 8 月济南的一个环境分离株的序列完全一致，提示病毒从济南传播到了临沂。贝叶斯系统发育方法表明，亚组 1a 中临沂分离株的最近共同祖先可追溯到 2010 年 12 月 24 日，表明该亚组可能于 2010 年 8 月至 12 月从济南输入。本研究表明，环境监测是追踪不同地区循环肠道病毒传播途径的敏感方法，并揭示 E6 相关无菌性脑膜炎是中国的一个新出现的问题。
