Intercity Spread of Echovirus 6 in Shandong Province, China: Application of Environmental Surveillance in Tracing Circulating Enteroviruses

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>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 (<jats:italic>n</jats:italic>= 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 (<jats:italic>n</jats:italic>= 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.</jats:p>

Molecular characterisation of enteroviruses and clinical findings from a cluster of paediatric viral meningitis cases in Tshwane, South Africa 2010–2011

“…Furthermore the characterisation of the circulating HEVs provides valuable epidemiological data which can be applied to identify and monitor outbreaks and can also be used to identify intercity [39] or intercountry spread of epidemic-related HEVs [29].…”

Environmental Surveillance of Human Enteroviruses in Shandong Province, China, 2008 to 2012: Serotypes, Temporal Fluctuation, and Molecular Epidemiology

“…Although environmental surveillance has served primarily as part of PV surveillance in many parts of the world, gradually more focus has been put on the circulation and molecular characterization of environmental nonpolio enteroviruses (NPEVs) (7)(8)(9)(10)(11)(12). In China, information on the circulating NPEVs is limited due to the absence of a specific enterovirus surveillance system.…”

“…Previously we reported the isolation of a rare recombinant poliovirus with chimeric capsid VP1 protein from sewage in 2009 (13) and molecular epidemiology and intercity spread of echovirus 6 (E6) in 2008 to 2011 (10,11), demonstrating the high sensitivity of the surveillance. In this report, we present an overview of serotype distribution and temporal dynamics of PVs and NPEVs from environmental surveillance from 2008 to 2012 and phylogenetic comparison of the relationship of Access RT-PCR system (Promega, USA).…”

Molecular Detection of Hepatitis E Virus in Rivers in the Philippines

“…The concentration and purification of these water samples was carried out as described previously 16 ; briefly, 500 mL of water was collected from each sampling site, and centrifuged at 3,000 rpm for 30 min at 4 C. Then, 2.5 mM MgCl 2 was added to the supernatant to a final concentration of 0.05 mM. The pH value was adjusted to 3.5.…”

“…Water samples were drawn at all locations during both the dry season (December 23, 2012) and the wet season (July 23, 2013), and were named D1 to D6 and W1 to W6, respectively. The water samples were kept at 4 C during transport.The concentration and purification of these water samples was carried out as described previously 16 ; briefly, 500 mL of water was collected from each sampling site, and centrifuged at 3,000 rpm for 30 min at 4 C. Then, 2.5 mM MgCl 2 was added to the supernatant to a final concentration of 0.05 mM. The pH value was adjusted to 3.5.…”