Acute norovirus gastroenteritis in children in a highly rotavirus-vaccinated population in Northeast Brazil.
Gastroenteritis is one of the most important causes of morbidity and mortality in children and an important etiological agent is norovirus.



We describe the occurrence and characteristics of norovirus diarrhoea in children from Sergipe, Northeast-Brazil, over two consecutive periods of three years following rotavirus vaccine introduction.



A cross sectional hospital-based survey conducted from October-2006 to September-2009 and from July-2011 to January-2013. Acute diarrhoea cases had a stool sample collected and tested for norovirus by RT-PCR and positive samples were sequenced.



In total 280 (19.6%) of 1432 samples were norovirus positive, including 204 (18.3%) of 1113 samples collected during the first period and 76 (23.9%) of 318 collected during the second period. The proportion of children with norovirus infection increased significantly through the second study period (χ2for trend=6.7; p=0.009), was more frequent in rotavirus vaccinated and in younger children (p<0.001). Of 280 norovirus-positive specimens, 188 (67.1%) were sequenced. Of these, 12 were genogroup I and 176 genogroup II. The main genotype was GII.4 (149/188, 79.3%), followed by GII.2 (6, 3.2%) and GII.6 (5, 2.6%).



Norovirus annual detection rates increased over the study period. The detection of norovirus was higher among young children.
Federal University of Sergipe, Aracaju, Brazil.
Victor S
VS
Santos
Federal University of Sergipe, Aracaju, Brazil. Electronic address: ricardoqgurgel@gmail.com.
Ricardo Q
RQ
Gurgel
Federal University of Sergipe, Aracaju, Brazil.
Sandra M M
SM
Cavalcante
Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK.
Andrew
A
Kirby
Federal University of Sergipe, Aracaju, Brazil.
Lilian P
LP
Café
Federal University of Sergipe, Aracaju, Brazil.
Maria J
MJ
Souto
Federal University of Sergipe, Aracaju, Brazil.
Silvio S
SS
Dolabella
Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Matheus R
MR
de Assis
Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Tulio M
TM
Fumian
Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Marize P
MP
Miagostovich
Department of Clinical Infection, Microbiology & Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
Nigel A
NA
Cunliffe
Liverpool School of Tropical Medicine, Liverpool, UK.
Luis E
LE
Cuevas
D001938:Brazil; D017250:Caliciviridae Infections / Q000453:epidemiology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003967:Diarrhea / Q000453:epidemiology* / Q000821:virology; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D015995:Prevalence; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
Brazil; Children; Diarrhoea; Norovirus; Rotavirus vaccine