molecular epidemiology and evolution of human enterovirus serotype 68 in thailand, 2006–2011分子流行病学和人类肠道病毒血清型的进化68年在泰国,2006 - 2011.pdfVIP

Molecular Epidemiology and Evolution of Human Enterovirus Serotype 68 in Thailand, 2006–2011 Piyada Linsuwanon, Jiratchaya Puenpa, Kamol Suwannakarn, Vittawat Auksornkitti, Preeyaporn Vichiwattana, Sumeth Korkong, Apiradee Theamboonlers, Yong Poovorawan* Chulalongkorn University, Bangkok, Thailand Abstract Background: Publications worldwide have reported on the re-occurrence of human enterovirus 68 (EV68), a rarely detected pathogen usually causing respiratory illness. However, epidemiological data regarding this virus in particular on the Asian continent has so far been limited. Methodology/Findings: We investigated the epidemiology and genetic variability of EV68 infection among Thai children with respiratory illnesses from 2006–2011 (n = 1810). Semi-nested PCR using primer sets for amplification of the 5 9- untranslated region through VP2 was performed for rhino-enterovirus detection. Altogether, 25 cases were confirmed as EV68 infection indicating a prevalence of 1.4% in the entire study population. Interestingly, the majority of samples were children aged .5 years (64%). Also, co-infection with other viruses was found in 28%, while pandemic H1N1 influenza/2009 virus was the most common co-infection. Of EV68-positive patients, 36% required hospitalizations with the common clinical presentations of fever, cough, dyspnea, and wheezing. The present study has shown that EV68 was extremely rare until 2009 (0.9%). An increasing annual prevalence was found in 2010 (1.6%) with the highest detection frequency in 2011 (4.3%). Based on analysis of the VP1 gene, the evolutionary rate of EV68 was estimated at 4.93 61023 substitutions/site/year. Major bifurcation of the currently circulating EV68 strains occurred 66 years ago (1945.31 with (1925.95–1960.46)95% HPD). Among the current lineages, 3 clusters of EV68 were categorized bas