Molecular epidemiology of Echovirus 30 in Fujian, China between 2001 and 2011

Temporal phylogeny and molecular characterization of echovirus 30 associated with aseptic meningitis outbreaks in China

BACKGROUND

An outbreak of aseptic meningitis occurred from June to August 2016, in Inner Mongolia Autonomous Region, China.

METHODS

To determine its epidemiological characteristics, etiologic agent, and possible origin, specimens were collected for virus isolation and identification, followed by molecular epidemiological analysis.

RESULTS

A total of 363 patients were clinically diagnosed from June 1st to August 31st 2016, and most cases (63.1%, n = 229) were identified between June 22nd and July 17th, with children aged 6 to 12 years constituting the highest percentage (68.9%, n = 250). All viral isolates from this study belonged to genotype C of echovirus 30 (E30), which dominated transmission in China. To date, two E30 transmission lineages have been identified in China, of which Lineage 2 was predominant. We observed fluctuant progress of E30 genetic diversity, with Lineage 2 contributing to increased genetic diversity after 2002, whereas Lineage 1 was significant for the genetic diversity of E30 before 2002.

CONCLUSIONS

We identified the epidemiological and etiological causes of an aseptic meningitis outbreak in Inner Mongolia in 2016, and found that Lineage 2 played an important role in recent outbreaks. Moreover, we found that Gansu province could play an important role in E30 spread and might be a possible origin site. Furthermore, Fujian, Shandong, Taiwan, and Zhejiang provinces also demonstrated significant involvement in E30 evolution and persistence over time in China.

A Large-Scale Outbreak of Echovirus 30 in Gansu Province of China in 2015 and Its Phylodynamic Characterization

Background

Echovirus 30 (E-30) has been investigated and reported worldwide and is closely associated with several infectious diseases, including encephalitis; myocarditis; and hand, foot, and mouth disease. Although many E-30 outbreaks associated with encephalitis have been reported around the world, it was not reported in northwest China until 2015.

Methods

The clinical samples, including the feces, serum, throat swabs, and cerebrospinal fluid, were collected for this study and were analyzed for diagnosis. E-30 was isolated and processed according to the standard procedures. The epidemiological and phylogenetic analysis were performed to indicate the characteristics of E-30 outbreaks and phylodynamics of E-30 in China.

Results

The E-30 outbreaks affected nine towns of Gansu Province in 2015, starting at a school of Nancha town and spreading to other towns within 1 month. The epidemiological features showed that children aged 6–15 years were more susceptible to E-30 infection. The genotypes B and C cocirculated in the world, whereas the latter dominated the circulation of E-30 in China. The genome sequences of this outbreak present 99.3–100% similarity among these strains, indicating a genetic-linked aggregate outbreak of E-30 in this study. Two larger genetic diversity expansions and three small fluctuations of E-30 were observed from 1987 to 2016 in China, which revealed the oscillating patterns of E-30 in China. In addition, the coastal provinces of China, such as Zhejiang, Fujian, and Shandong, were initially infected, followed by other parts of the country. The E-30 strains isolated from mainland of China may have originated from Taiwan of China in the last century.

Conclusion

The highly similar E-30 genomes in this outbreak showed an aggregate outbreak of E-30, with nine towns affected. Our results suggested that, although the genetic diversity of E-30 oscillates, the dominant lineages of E-30 in China has complex genetic transmission. The coastal provinces played an important role in E-30 spread, which implied further development of effective countermeasures. This study provides a further insight into the E-30 outbreak and transmission and illustrates the importance of valuable surveillance in the future.

Global phylodynamics of Echovirus 30 revealed differential behavior among viral lineages

Echovirus 30 (E30) is an important causative agent of aseptic meningitis worldwide. Despite this, the global and regional dispersion patterns, especially in South America, are still largely unknown. We performed an in-depth analysis of global E30 population dynamics, by using the VP1 sequences of 79 strains isolated in Argentina, between 1998 and 2012, and 856 sequences from GenBank. Furthermore, the 3D^pol regions of 329 sequences were analyzed to study potential recombination events. E30 evolution was characterized by co-circulation and continuous replacement of lineages over time, where four lineages appear to circulate at present and another four lineages appear to have stopped circulating. Five lineages showed a global distribution, whereas three other lineages had a more restricted circulation pattern. Strains isolated in South America belong to lineages E and F. Analysis of the 3D^pol region of Argentinean strains indicated that recombination events occurred in both lineages.

Analysis of enterovirus types in patients with symptoms of aseptic meningitis in 2014 in Shandong, China

We reviewed the epidemiological and clinical characteristics of 927 aseptic meningitis patients in Shandong in 2014, and the phylogeny of predominant enterovirus (EV) types causing this disease was analyzed. A total of 209 patients that were positive for EV were identified by both cell culture and a reverse transcription-seminested PCR in cerebrospinal fluid samples. The positive patients were most likely to be children within 15 years of age, had symptoms such as fever, vomiting and nausea (P＜ .05). The 209 EV sequences belonged to 11 types, and coxsackievirus B5, echovirus types 6 and 30 were predominant types. VP1 analysis exhibited multiple lineages were co-circulating. The significance of the study could come from the fact that surveillance is important to monitor the prevalence of EV types in population, which shows enterovirus meningitis maintains an important public health problem in China.

Echovirus serotypes circulating in Malaysia from 2002 to 2013

OBJECTIVE

To identify the circulating serotypes of human echovirus in Malaysia from 2002 to 2013.

METHODS

A total of 31 retrospective samples from non-polio acute flacid paralysis, hand-food-and-mouth disease, viral meningitis and enterovirus cases were subjected to amplification of partial VP1 gene by RT-PCR.

RESULTS

Sequencing and phylogenetic analysis of the partial sequences identified presence of human echovirus and human coxsackie viruses. It was found that echovirus 11 was the commonly circulating serotype followed by echovirus 6, echovirus 7, echovirus 3, echovirus 9, echovirus 30 and echovirus 1 in decreasing order. Additionally two types of human coxsackie virus isolates were detected which were coxsackie A24 and B3.

CONCLUSIONS

From the findings, there is a possibility that echovirus 11 is the predominant serotype among Malaysian patients with echovirus infection. However, a larger sample size will yield a more confident result to support this evidence.

Elucidation of echovirus 30's origin and transmission during the 2012 aseptic meningitis outbreak in Guangdong, China, through continuing environmental surveillance

An aseptic meningitis outbreak occurred in Luoding City of Guangdong, China, in 2012, and echovirus type 30 (ECHO30) was identified as the major causative pathogen. Environmental surveillance indicated that ECHO30 was detected in the sewage of a neighboring city, Guangzhou, from 2010 to 2012 and also in Luoding City sewage samples (6/43, 14%) collected after the outbreak. In order to track the potential origin of the outbreak viral strains, we sequenced the VP1 genes of 29 viral strains from clinical patients and environmental samples. Sequence alignments and phylogenetic analyses based on VP1 gene sequences revealed that virus strains isolated from the sewage of Guangzhou and Luoding cities matched well the clinical strains from the outbreak, with high nucleotide sequence similarity (98.5% to 100%) and similar cluster distribution. Five ECHO30 clinical strains were clustered with the Guangdong environmental strains but diverged from strains from other regions, suggesting that this subcluster of viruses most likely originated from the circulating virus in Guangdong rather than having been more recently imported from other regions. These findings underscore the importance of long-term, continuous environmental surveillance and genetic analysis to monitor circulating enteroviruses.

Molecular epidemiology of echoviruses 11 and 30 in Russia: different properties of genotypes within an enterovirus serotype

Over 100 known enterovirus serotypes differ in their epidemiological and pathogenic properties. Much less is known about variation of these features on a sub-serotype level, such as genotypes. Echovirus 11 (E11) and E30 are amongst the most frequent causative agents of aseptic meningitis. We studied the molecular epidemiology of these pathogens to evaluate potential epidemiological and pathogenic dissimilarities of their genotypes. The complete VP1 genome region was sequenced for 97 E11 and 62 E30 isolates collected in Russia from 2008 to 2012, and they were studied in comparison with all 140 E11 and 432 E30 sequences available in GenBank. A geographic pattern of genotype prevalence was observed for both types. Russian E11 isolates belonged mainly to A genotype, which is common in Asia, and D5, which is predominant in Europe. For E30, genotype III by classification of Ke et al. (2011), also termed genotype a by Bailly et al. (2009), was endemic in Russia from 2003 to 2012, while it was not detected in Europe and North America during this time. The E30 genotypes VI-B, VI-G, and VI-H (e, f and h) were regularly introduced from different countries, became predominant and vanished after no more than 4years. In addition to geographic patterns, E11 genotypes also differed by isolation source. Genotype A2 viruses were significantly more often found in sewage, compared to genotype D5 that was isolated from both sewage and human samples. In addition, there was evidence of a different capacity for international transfers among E11 GtA subclusters.

Molecular epidemiology of human enterovirus associated with aseptic meningitis in Shandong Province, China, 2006-2012

Background

Human enteroviruses (HEVs) are common causes of acute meningitis. However, there is limited information about HEV associated with aseptic meningitis in mainland China because it has not been classified as a notifiable disease.

Objectives

To characterize the HEVs associated with sporadic aseptic meningitis in China and to analyze their genetic features.

Study Design

Cerebrospinal fluid, throat swab and feces specimens were collected from patients with aseptic meningitis in 5 sentinel hospitals in Shandong Province, China between 2006 and 2012. Virological investigation (viral isolation and molecular identification) and phylogenetic analysis were performed.

Results

A total of 437 hospitalized patients were reported, and enteroviruses were detected in the specimens from 84 patients (19.2%) and were identified into 17 serotypes. The nine main serotypes were echovirus (E) 30 (27.4%), EV71 (13.1%), coxsackievirus (CV) B1 (9.5%), CVB3 (7.1%), CVB5 (7.1%), E6 (7.1%), E9 (7.1%), CVA9 (6.0%), and CVA10 (3.6%). Monthly distribution of isolated enteroviruses revealed a major peak in summer-fall season and a small second peak in winter constituted totally by EV71. Sequence analysis on VP1 coding region suggested Shandong strains had great genetic divergence with isolates from other countries.

Conclusions

Multiple serotypes were responsible for enterovirus meningitis in mainland China. Aseptic meningitis caused by EV71 and coxsackie A viruses–the predominant pathogens for the hand, foot, and mouth disease–is currently an important concern in mainland China.

Complete genome sequence analysis of human echovirus 30 isolated during a large outbreak in Guangdong Province of China, in 2012

In May and June 2012, an outbreak of aseptic meningitis caused by Echovirus 30 (E30) occurred on a large scale in Luoding, Guangdong Province, China. Our team successfully isolated one subtype, strain 2012EM161, and its complete genome was sequenced. The phylogenetic tree of viral protein (VP) 1 gene sequences showed that the viral isolate was similar to the E30 strain prevalent in Fujian (2011), with identity of 98.05–99.32 % and 98.63–99.32 % for nucleotides and amino acids respectively. Whole genome-based phylogenetic analysis indicated that 2012EM161 contained the most proximate consensus to DQ246620 (Zhejiang, 2003) and FDJS03 (AY948442, Jiangsu, 2005), with nucleotide homogeneity of 87.09 % and 86.98 % respectively. The RDP4.16 and Simplot analysis showed that the newly discovered 2012EM161 was probably a recombinant, which was closely related to the strain of E30 (DQ246620) in the first half of the genome and the strain of E6 (JX976771) in genomic P3 region. The whole genome sequence of 2012EM161 will allow further study of the origin, evolution, and the molecular epidemiology of E30 strains.