Asymptomatic circulation of HEV71 in Norway. Virus Res

Charles University in Prague, Praha, Praha, Czech Republic
Virus Research (Impact Factor: 2.32). 02/2007; 123(1):19-29. DOI: 10.1016/j.virusres.2006.07.015
Source: PubMed


Widespread circulation of human enterovirus 71 was discovered in a prospective study of fecal samples obtained from healthy Norwegian children. Molecular characterization of the virus determined that it belonged to genotype C1. Complete sequencing of this strain, HEV71 804/NO/03, revealed differences in the 5'UTR and polymerase with respect to more pathogenic genotypes that may explain its reduced neurovirulence.

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    • "In Europe, large outbreaks of polio-like disease caused by EV71 occurred in Bulgaria in 1975 and in Hungary in 1978. Thereafter, EV71 did not attract major attention until recently, when widespread asymptomatic circulation and detection from isolated neurological cases and minor outbreaks were reported from several European countries [5]–[8]. No major outbreaks have so far occurred in Europe. "
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    ABSTRACT: Enterovirus 71 (EV71) is an emerging human pathogen causing massive epidemics of hand, foot and mouth disease with severe neurological complications in Asia. EV71 also circulates in Europe, however it does not cause large outbreaks. The reason for distinct epidemiological patterns of EV71 infection in Europe and Asia and the risk of EV71 epidemic in Europe and Russia remain unknown. Seroepidemiology of EV71 and molecular epidemiology of occasional EV71 isolates were studied to explore circulation of EV71 in Russia. In six regions of Russian Federation, seroprevalence of EV71 in sera collected in 2008 ranged from 5% to 20% in children aged 1-2 years and from 19% to 83% in children aged 3-5 years. The seroprevalence among elder children was significantly higher (41-83% vs. 19-27%) in Asian regions of Russia. EV71 strains identified in Russia in 2001-2011 belonged to subtypes C1 and C2, while genotype C4 that was causing epidemics in Asia since 1998 emerged in 2009 and became dominant in 2013.
    PLoS ONE 05/2014; 9(5):e97404. DOI:10.1371/journal.pone.0097404 · 3.23 Impact Factor
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    • "Han et al. reported positive rates of 0, 4.93 and 10.29% in throat swabs and 2.86, 3.94 and 8.82% in stools from three villages with different HFMD prevalence rate [9]. Studies conducted among children in Finland [33] and Norway [10,30,31] reported an EV71 positive rate of 0.3 and 1.4% from stool samples respectively, and isolation rate of 1.8% from stool samples were reported among children in Shenzhen, China [29]. Herein we demonstrated that 23.2% and 15.0% out of 254 healthy children carried HEV and EV71 respectively. "
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    ABSTRACT: To determine the prevalence of human enteroviruses (HEVs) among healthy children, their parents, and children with hand, foot, and mouth disease (HFMD). We conducted a case-control study that included throat samples from 579 children with HFMD and from 254 healthy controls. Throat samples from 49 households (98 parents and 53 healthy children) were also analyzed. Phylogenetic analysis was carried out to study genetic relationships of EV71 strains. The HEV positive rate in HFMD patients was significantly higher than that in healthy controls (76.0% vs. 23.2%, P < 0.001). The EV71 (43.7% vs. 15.0%, P < 0.001), CVA16 (18.0% vs. 2.8%, P < 0.001), and CVA10 (5.7% vs. 0.8%, P = 0.001) serotypes were significantly overrepresented in HFMD patients in comparison to healthy children. Other HEV serotypes were detected with comparable frequency in cases and controls. The HEV positive rate in severe HFMD patients was significantly higher than that in mild group (82.1% vs. 73.8%, P = 0.04). The EV71 (55.0% vs. 39.7%, P = 0.001) and CVA16 (11. 9% vs. 20.0%, P = 0.024) positive rate differed significantly between severe and mild HFMD patients. Other HEV serotypes were detected with comparable frequency between severe and mild HFMD patients. Among 49 households, 22 households (44.9%) had at least 1 family member positive for HEV. Children had significantly higher HEV positive rate than adult (28.3% vs. 14.3%, P = 0.037). The HEV positive rate was similar between mothers and fathers (12.24% vs. 16.32%, P = 0.56). The VP1 sequences of EV71 from HFMD patients and healthy children were nearly identical and all were clustered in the same clade, C4a. Our study demonstrated the co-circulation of multiple HEV serotypes in children with and without HFMD during epidemic. Our study deserves the attention on HFMD control.
    BMC Infectious Diseases 12/2013; 13(1):606. DOI:10.1186/1471-2334-13-606 · 2.61 Impact Factor
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    • "The number of EV71-associated HFMD cases was relatively low in Europe compared to that in the Asia-Pacific region. In a prospective study from Norway (57), EV71 was detected in stool specimens from asymptomatic children, and the absence of disease may be due to host factors (immune system, genetic effect, nutritional and hygiene status) and/or viral factors. Since HFMD is not a disease under surveillance in Europe and healthy individuals are usually not the subjects under surveillance, the prevalence of EV71 may be underestimated (23, 58–60). "
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    ABSTRACT: Human enterovirus 71 (EV71) epidemics have affected various countries in the past 40 years. EV71 commonly causes hand, foot and mouth disease (HFMD) in children, but can result in neurological and cardiorespiratory complications in severe cases. Genotypic changes of EV71 have been observed in different places over time, with the emergence of novel genotypes or subgenotypes giving rise to serious outbreaks. Since the late 1990s, intra- and inter-typic recombination events in EV71 have been increasingly reported in the Asia-Pacific region. In particular, 'double-recombinant' EV71 strains belonging to a novel genotype D have been predominant in mainland China and Hong Kong over the last decade, though co-circulating with a minority of other EV71 subgenotypes and coxsackie A viruses. Continuous surveillance and genome studies are important to detect potential novel mutants or recombinants in the near future. Rapid and sensitive molecular detection of EV71 is of paramount importance in anticipating and combating EV71 outbreaks.
    Emerging Health Threats Journal 09/2013; 6:19780. DOI:10.3402/ehtj.v6i0.19780
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