Acute infantile gastroenteritis associated with human enteric viruses in Tunisia

Abstract

This prospective study, conducted from January 2003 to June 2005, investigated the incidence and the clinical role of various enteric viruses responsible for infantile gastroenteritis in 632 Tunisian children presenting in dispensaries (380 children) or hospitalized (252 children) for acute diarrhea. At least one enteric virus was found in each of 276 samples (43.7%). A single pathogen was observed in 234 samples, and mixed infections were found in 42 samples. In terms of frequency, rotavirus and norovirus were detected in 22.5 and 17.4% of the samples, respectively, followed by astrovirus (4.1%), Aichi virus (3.5%), adenovirus types 40 and 41 (2.7%), and sapovirus (1.0%). The seasonal distribution of viral gastroenteritis showed a winter peak but also an unusual peak from May to September. The severity of the diarrhea was evaluated for hospitalized infants. No significant differences were observed between rotavirus and norovirus infections with regard to the incidence and the clinical severity of the disease, especially in dehydration.

FIG. 1.

Distribution of monoinfections and mixed infections in hospitalized and nonhospitalized children. RVs and NoVs were significantly more frequent in hospitalized than in nonhospitalized children, as shown by χ² or Fisher's exact test results (*, P = 0.002; **, P < 0.001). No significant differences were observed in comparisons of the rates of incidence of RVs and NoV infections in each population by analysis of percentages with χ² or Fisher's exact test. AdV 40/41, type 40 and 41 HAdV.

FIG. 2.

Distribution of positive samples of the enteric viruses detected in Tunisian children for the following three age groups: ≤24 months, 25 to 60 months, and >60 months. RVs were significantly more frequent than NoVs (*, P = 0.042) in children under 24 months old, whereas no significant differences were observed in the other 25-to-60-month and >60-month age groups (P = 0.50 and P = 0.10, respectively). RV grA, group A RV; AdV 40/41, type 40 and 41 HAdV.

FIG. 3.

Monthly distribution of viral infections in hospitalized children between January 2003 and May 2005 in the district of Monastir, Tunisia. Most of the RV and NoV infections occurred in winter and from June to September, and these two peaks of incidence together accounted for 80.5% and 62.2% of RV and NoV infections, respectively. HAdV, type 40 and 41 HAdV. Reading left to right across the bottom of the figure, the letters J, F, M, A, M, J, J, A, S, O, N, and D represent the months January, February, March, April, May, June, July, August, September, October, November, and December, respectively.