Molecular Characterization of Rotavirus Strains Causing Gastroenteritis in Children under 5 Years in Cairo, Egypt

Globally, human rotavirus (RV) remains the most common cause of severe diarrhea in children, causing 453,000 deaths per year and proximately 2.4 million hospitalization among children aged less than 5 years, with a maximum incidence in the developing countries [1-3]. Transmissions of RVs occur mainly via fecal-oral contact but it also might be transmitted by respiratory spread [4,5]. RV group A is the most cause of viral gastroenteritis in human and at least 27 G-serotypes and 32 P-serotypes have been identified [6,7]. Among them, 12 G-serotypes (G1 to G6, G8 to G12, G22) and 15 P-serotypes (P[1] to P[11], P[14], P[19], P[25]) have been identified in human [8-11]. Globally, G1 to G4 and recently G9 are the major G-serotypes in human. Globally uncommon G-serotypes such as G5, G6, G8, and G10 to G12 may be detected regionally [911]. On the other hand, P[4], P[6] and P[8] are the most prevalent human P-serotypes [12,13], while rare human P-serotypes P[9], P[11] and P[14] are increasingly identified locally in different areas of the world [14,15]. Furthermore, novel RV serotypes can be produced from mixed infection of segmented RV genome. Two oral live attenuated vaccines, pentavalent RotaTeq (Merck and Co. Inc.), consisting of G1-G4 types with P[8], and monovalent Rotarix (GlaxoSmithKline), consisting of G1 with P[8], to prevent RV gastroenteritis are currently licensed in lower middle income countries [16] and European countries [17]. In this study, we studied the incidence of RV genotypes among children less than 5 years old circulating in Egypt to determine whether the current vaccines cover the most circulating RV among children below 5 years old in Egypt.