ABSTRACT
Diarrheal diseases can be caused by viral, bacterial and parasitic infections. This paper provides a preliminary image of diarrhea with regards to etiology and epidemiologic factors in Tunisian children less than five years of age. Overall, 124 diarrhoeal stools were collected from patients suffering from acute diarrhea and 54 stool samples from healthy children. All stools were examined for the presence of enteric pathogens. In diarrheagenic children, 107 pathogenic bacteria were isolated [12 Salmonella spp. [9.7%] and 95 diarrheagenic Escherichia coli strains [76.6%]: 29 enteroaggregative E.coli [EAEC] [23.4%], 15 enteroinvasive E.coli [EIEC] [12.1%], 17 enteropathogenic E.coli [EPEC] [13.7%], 26 enterotoxigenic E.coli [ETEC] [21%] and 2 enterohemoragic E.coli [EHEC] [1.6%]. However, in the control group, 23 pathogenic E.coli strains were isolated [42.6%] 8 EAEC [14.8%], 12 EIEC [22.2%] and 3 EPEC [5.5%]. Among diarrheagenic E.coli [DEC], only ETEC strains were significantly recovered from diarrheagenic children than from healthy controls [P < 0.0003]. Group A rotavirus was identified in 33.9% [n=42] of diarrheagenic children and in 11.1% among the control group [n=6]. Concerning norovirus, 8.9% [n=11] of the samples collected from diarrheagenic children and 9.2% [n=5] from the control group were positive. The prevalence of rotaviruses and Salmonella spp were also significantly higher in patients with diarrhea than in controls [P = 0.002 and P < 0.019, respectively]. Finally, enteropathogenic parasites [Entamoeba coli and cryptosporidium Oocystes] were isolated from 4.8% and 9.2% of diarrheagenic and control children, respectively. These results provide baseline data about the relative importance of different enteropathogens in Tunisian children
ABSTRACT
Wastewater frequently has been contaminated by enteric viruses, which can cause gastroenteritis, hepatitis, and other viral diseases. Since current water treatments do not ensure their complete removal and they become contaminants of the water environment. In order to monitor and assess the prevalence and the seasonal incidence of enteric viruses contaminating wastewater, a total of 93 samples were collected from the stations of Sayada-Lamta-Bouhjar and El Frina. The purpose of this study is to establish a rapid, sensitive and specific RT-PCR method using highly conserved primers to detect enteric viruses [caliciviruses, enteroviruses and hepatitis A viruses] circulating in the area of Monastir, during the period from October 2005 to July 2006. Our study shows that the caliciviruses were detected in 67.56%of the wastewater samples and present an essentially winter distribution with a specific peak in spring. The enteroviruses were detected in 35.13%of the samples tested and present a regular circulation during the year with a predominance in the summer and early fall. Finally, the presence of hepatitis A viruses was noted especially in winter in 10.81%of the wastewater samples. We notice that current wastewater treatment methods are sometimes not efficient to eliminate enteric viruses