Rotaviruses and noroviruses are leading viral causes of diarrhoea in children. A cross-sectional study was undertaken among children aged <5 years with acute gastroenteritis at Al-Jala Children's Hospital, Tripoli, Libya, from October 2007 to September 2008. Of 1,090 fecal samples collected, 260 from inpatients and 830 from outpatients, all inpatients and approximately a third of outpatients, selected systematically, were investigated for rotavirus and norovirus infection by ELISA and real-time RT-PCR, respectively. Of 520 fecal samples examined (inpatients=260, outpatients=260), 164 (31.5%) had rotavirus and 91 (17.5%) had norovirus detected. Rotavirus was identified more often among inpatients than outpatients (35.8% vs. 27.3% respectively, P=0.038). Norovirus was detected more commonly among outpatients than inpatients (21.2% vs. 13.8% respectively, P=0.028). The peak incidence of infection with both viruses was among children aged between 6 and 11 months. The number of rotavirus cases was highest between November and June with a peak detection rate of 50% in January. Norovirus occurred most commonly from May through August with a peak detection rate of 47% in August. The most prevalent rotavirus genotypes were P[8], G9 (n=116, 65.9%), followed by P[8],G1 (n=49, 27.8%); a single P[9], G3 strain was detected. There were seven distinct electropherotypes among the G9 strains and all belonged to VP7 Lineage III. Among 91 noroviruses identified, 90 were genogroup II. Of 26 genogroup II noroviruses examined, all were genotype GII.4. Rotaviruses and noroviruses are both important causes of gastrointestinal infection among young children in Libya. © 2011 Wiley-Liss, Inc..
