Molecular epidemiology and clinical characterization of group A rotavirus infections in Tunisian children with acute gastroenteritis
ABSTRACT Rotaviruses are the most common cause of severe viral gastroenteritis in early childhood worldwide. Thus, the objectives of our study were to determine the molecular epidemiology and the clinical features of rotavirus gastroenteritis in Tunisia. Between January 2003 and April 2007, a prospective study was conducted on 788 stool samples collected from children under 12 years of age who were suffering from acute gastroenteritis. Rotavirus was detected by multiplex RT-PCR in 27% (n = 213) of samples, among them 79.3% (n = 169) cases were monoinfections. The frequency of rotavirus infections was significantly higher among inpatients (29%) than among outpatients (13%) (P < 0.001). The seasonal distribution of rotavirus diarrhea showed a winter peak, with an unusual peak from June to September. The mean duration of hospitalization was 6.5 ± 8.1 days and the mean age was 15.8 ± 22.8 months for rotavirus monoinfections. Fever, vomiting, abdominal pain, and dehydration were observed in 88, 98, 13, and 80 cases, respectively, in children with rotavirus monoinfections. G3P (45.6%) and G1P (23.9%) were the most common genotypes found in our study. The determination of rotavirus infection prevalence and the characterization of the rotavirus strains circulating will help us to better understand the molecular biology and epidemiology of the disease in our country.
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ABSTRACT: Different types of viruses are the leading cause of acute diarrhea among infants and young children worldwide. Epidemiological surveillance of viral agents is critical for the develop.ment of effective preventive measures, including vaccines. This study aimed to determine the prevalence of the four major enteropathogenic viruses-rotavirus, norovirus, adenovirus and astrovirus-in children over 7 years of age. A cross-sectional descriptive study conducted on stool specimens of children with acute gastroenteritis admitted to the Pediatrics Unit of 17 Shahrivar Hospital in Borazjan, Iran from October 2008 to September 2010. Acute gastroenteritis was defined as >=3 loose watery stools per 24 hours. A total of 375 stool samples were collected from hospitalized children aged < 7 years old with acute gastroenteritis. All samples were investigated by using enzyme-linked immunosorbent assay for the presence of viral antigens. Rotavirus was detected in 91 (24.3%) of the patients whereas the prevalence of norovirus, adenovirus and astrovirus was 12.5%, 5.1% and 2.4%, respectively. On average, 75.9% of children with viral diarrhea were younger than 2 years old (P=.023). All the strains of viral gastroenteritis studied peaked in the autumn, except for adenovirus which peaked in spring (P=.015). The most common clinical symptoms included diarrhea (92.2%), vomiting (68.7%), abdominal cramp (60.8%) and moderate dehydration (57.2%). Since nearly half of gastroenteritis cases (44.3%) were due to viral agents, testing for the viral antigens may guide the clinical approach to those patients with acute diarrhea particularly in the case of children less than 2 years old, and during cold seasons.Annals of Saudi medicine 01/2012; 33(2):124-9. DOI:10.5144/0256-4947.2013.124 · 0.71 Impact Factor
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ABSTRACT: Viral gastroenteritis can be a life-threatening disease in infants and young children, especially in developing countries. The aim of this study was to continue the epidemiological surveillance of norovirus (NoV) infections in Tunisian children suffering from acute gastroenteritis. Surveillance was initiated in January 2003, to monitor potential variations in strains over time, in terms of frequency and diversity of NoV genotypes, and more particularly the potential emergence of new GII.4 variants following the 2004 Hunter variant. From April 2007 to April 2010, a total of 407 stool specimens were collected from sporadic cases (238 inpatients and 169 outpatients). Furthermore, 28 stool samples were collected from children involved in 3 gastroenteritis outbreaks. Stool specimens were screened for NoV genogroup I (GI) and II (GII) by RT-PCR. NoV strains were genotyped, and variants identified, based on sequence and phylogenetic analyses of the polymerase and capsid genes. NoVs were detected in 38 sporadic cases (9.3%) and 21 epidemic cases (75%). Great diversity was observed throughout the period, with seven distinct NoV genotypes characterized in sporadic cases, and three in outbreaks. GIIb/II.3 and GII.4 were predominant globally, with fluctuations of their prevalence over time. Interestingly, the Hunter variant, which was the unique GII.4 variant observed from 2003 to April 2007 in the region of Monastir, was replaced by the 2006b variant. NoV is an important enteropathogen responsible for viral gastroenteritis among infants and children in Tunisia, and the infecting strains between 2007 and 2010 were different from those in previous years. J. Med. Virol. © 2013 Wiley Periodicals, Inc.Journal of Medical Virology 06/2013; 85(6). DOI:10.1002/jmv.23552 · 2.22 Impact Factor
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ABSTRACT: Human enteric viruses constitute a public health concern due to their low infectious dose and their resistance to environmental factors and to inactivation processes. We aimed at assessing the performance of a laboratory scale Submerged membrane bioreactor (SMBR) treating abattoir wastewaters for Rotavirus (RV) and total coliphages removal. We also aimed at evaluating removal efficiency of enteric viruses through conventional activated sludge treatment by measuring concentrations of total coliphages, considered as fecal and viral contamination indicators, with double-layer agar technique. The Log10 reduction values of bacteriophages ranged from 1.06 to 1.47. Effluents were analyzed to investigate and quantify RV, hepatitis A virus (HAV), Hepatitis E virus (HEV), Noroviruses genogroup I (NoV GI) and genogroup II (NoVGII), and Enterovirus (EV) by real-time PCR, using standardized detection kits (ceeramTools detection kits(®)). All effluent samples were positive for RV; concentrations ranged from 5.2 × 10(5) to 1.3 × 10(7) genome copies/L. These results highlight the inefficiency of conventional biological process for viral removal. A complete removal of RV during Membrane Bioreactor treatment was obtained. To the best of our knowledge, this is the first study providing an evidence of removal of RV simultaneously with total coliphages by SMBR.Current Microbiology 07/2015; DOI:10.1007/s00284-015-0882-y · 1.36 Impact Factor