Clinical surveillance for human astrovirus in Monastir region, Tunisia.

Abir Monastiri,Sabeur Hamami,Jordi Serra-Cobo,Nabil Ben Salem Abid,Susana Guix,Badereddine Mechri,Mahjoub Aouni,Neji Gueddiche,Marc Lopez-Roig,Lamjed Boughzala

doi:10.1186/s12889-016-2726-5

Abstract

Background/aimsAstroviruses (AstVs) are enteric viruses that can cause gastroenteritis in children. This study is part of monitoring the circulation of astroviruses in children hospitalized and/or outpatients for acute gastroenteritis at the primary care center of Ouerdanine or at the Pediatric Department of the University Hospital Fattouma-Bourguiba (Monastir, Tunisia). The aims of our study were to know the prevalence of human astrovirus in clinical samples of children, characterize the strains and evaluate the infectivity of isolated strains on cell culture.MethodsFifty stool samples were collected from children under five years old in the region of Monastir (Tunisia) from October 2010 to June 2011. All specimens were subjected to RT-PCR amplification followed by sequencing and phylogenetic analysis.ResultsThe study shows a low prevalence of astrovirus (4 %) in children. The two positive samples obtained were HAstV type 3. Samples that were RT-PCR positive were cultured in CaCO-2 cells and the presence of infectious viral particles was confirmed. The phylogenetic analysis shows that the different HAstV-3 strains isolated in Tunisia are grouped into two clusters. The first cluster includes strains obtained in 2004, which belong to lineage HAstV-3a, while strains isolated in 2010 belong to lineage HAstV-3c.ConclusionsThis study is part of monitoring the circulation of astroviruses in children younger than five years old from Monastir region, Tunisia. The results show low prevalence (4 %). All genotyped samples belonged to lineage HAstV-3c, which could be presently emerging. Two different lineages have been isolated in Tunisia: HAstV-3a in 2004 and HAstV-3c in 2010.

Highlights

Astroviruses (AstVs) are enteric viruses that can cause gastroenteritis in children and a severe disease in immunocompromised and elderly people [1, 2]
The two sequences obtained from ORF2 belonged to lineage human astrovirus (HAstV)-3c [15]
They shared 98.6 % and 97.9 % of nucleotide identity with the HAstV-3c reference strains KC896091 and AB551378 isolated in Pakistan and India in 2009, respectively

Summary

Introduction

Astroviruses (AstVs) are enteric viruses that can cause gastroenteritis in children and a severe disease in immunocompromised and elderly people [1, 2]. The prevalence rate of human astrovirus (HAstV) infection ranged from 2 % to 9 % among children with diarrhea, incidences over 60 % have been reported [3]. The main symptom of astrovirus infection is watery diarrhea, which is Astroviruses are a non-enveloped positive-strand RNA viruses belonging to the Astroviridae family [5]. The first includes the classic eight serotypes of HAstVs (HAstV-1 to HAstV-8). The other two groups (MLB and VA clades), identified in 2009, are prevalent but their pathogenic role in humans requires further characterization [3]. Epidemiological surveys on classic HAstVs show that HAstV-1 is the most common serotype identified worldwide in children [6, 7], while HAstV-6, and −7 are less frequent [8, 9]. A precedent study, performed in Tunisia, showed the predominance of genotype HAstV-1 [10]

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