Epidemiological and molecular features of norovirus infections in Italian children affected with acute gastroenteritis.
During a 5-year (2007-2011) surveillance period a total of 435 (15·34%) of 2834 stool specimens from children aged <14 years with acute gastroenteritis tested positive for norovirus and 217 strains were characterized upon partial sequence analysis of the polymerase gene as either genogroup (G)I or GII. Of the noroviruses, 99·2% were GII with the GII.P4 genotype being predominant (80%). GII.P4 variants (Yerseke 2006a, Den Haag 2006b, Apeldoorn 2008, New Orleans 2009) emerged sequentially during the study period. Sequence analysis of the capsid gene of 57 noroviruses revealed that 7·8% were recombinant (ORF1/ORF2) viruses including GII.P7_GII.6, GII.P16_GII.3, GII.P16_GII.13, GII.Pe_GII.2, and GII.Pe_GII.4, never identified before in Italy. GII.P1_GII.1, GII.P2_GII.1, GII.P3_GII.3 and GII.P6_GII.6 strains were also detected. Starting in 2011 a novel GII.4 norovirus with 3-4% nucleotide difference in the polymerase and capsid genes from variant GII.4 New Orleans 2009 was monitored in the local population. Since the epidemiology of norovirus changes rapidly, continuous surveillance is necessary to promptly identify the onset of novel types/variants.
Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine,University of Parma,Parma,Italy.
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Medici
Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine,University of Parma,Parma,Italy.
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Tummolo
Department of Veterinary Medicine,University Aldo Moro of Bari,Valenzano, Bari,Italy.
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Martella
Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine,University of Parma,Parma,Italy.
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Chezzi
Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine,University of Parma,Parma,Italy.
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Arcangeletti
Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine,University of Parma,Parma,Italy.
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De Conto
Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine,University of Parma,Parma,Italy.
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Calderaro
D000208:Acute Disease; D017677:Age Distribution; D017250:Caliciviridae Infections / Q000175:diagnosis / Q000453:epidemiology*; D036022:Capsid Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D007558:Italy / Q000453:epidemiology; D008297:Male; D017720:Molecular Epidemiology; D029322:Norovirus / Q000235:genetics* / Q000302:isolation & purification*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D012367:RNA, Viral / Q000235:genetics; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution
D036022:Capsid Proteins; D012367:RNA, Viral