The Epidemiology of Human Rotavirus Associated with Diarrhoea in Kenyan Children: A Review by Nicholas M. Kiulia, a Rose Kamenwa, b Grace Irimu, b James O. Nyangao, c Zipporah Gatheru, c Atunga Nyachieo, a Andrew D. Steele, d and Jason M. Mwenda a a Enteric Viruses Research Group, Institute of Primate Research, P.O. Box 24481, 00502, Karen, Nairobi, Kenya b Kenyatta National Hospital, Department of Paediatrics, Medical School, University of Nairobi c Kenya Medical Research Institute, P.O. Box 54628, 00200, Nairobi, Kenya d Medical Research Council (MRC), Diarrhoeal Pathogens Research Unit, Medunsa Campus, University of Limpopo, P.O. Box 173, MEDUNSA, 0204, Pretoria, South Africa Summary Rotavirus gastroenteritis still remains a major cause of morbidity and mortality among young children in developing countries, with »150 000–200 000 deaths occurring annually in sub-Saharan Africa. We reviewed papers published over the last 30 years on the epidemiology of rotavirus diarrhoea among the hospitalized and out-patient children in Kenya. The analysis shows rotavirus prevalence of 6–56% with diarrhoea occurring throughout the year and generally exhibiting distinct peaks during the dry months. Among the common genotype, G1 was the most predominant up to the year 2002 but more recently there has been an emergence of genotype G9 as the most predominant genotype and to a less extent G8. It is important to continue rotavirus surveillance in Kenya to determine accurately the burden of rotavirus disease and the emerging new genotypes. This will assist policy makers in decision making on rotavirus vaccine introduction and determining the impact of the vaccine. Key words: rotavirus, genotypes, vaccine. Introduction Rotavirus gastroenteritis still remains a major cause of morbidity and mortality among infants and young children in both developed and developing countries [1, 2]. It is estimated that 600 000 rotavirus-related deaths occur among children of <5 years globally every year due to increased diarrhoea hospitaliza- tions caused by rotavirus [3]. Studies done in Vietnam showed more than double increase from 21 to 56% rotavirus detection rates in children hospitalized with diarrhoea over a period of 15 years (1986–2001) [4, 5]. A similar surveillance done in nine Asian countries showed rotavirus prevalence of 45% in children hospitalized with diarrhoea [6]. Global prevalence of rotavirus derived from several studies conducted throughout the world have shown that rotaviruses account for 15–71% (average, 33%) of acute gastroenteritis requiring hospitalization of infants and young children [7]. Sanitation seems to have less impact on rotavirus infection rates as rotavirus infection occurs both in developed countries with high social economic levels and good sanitation standards as well as developing countries with poor sanitation [1, 8–14]. Nevertheless, mortality is higher in developing countries [8]. Herein, we highlight the epidemiology of rotavirus infection and review the prevalence of rotavirus strains circulating in Kenya. Rotavirus Strains Classification On the basis of antigenic and genetic diversities, 15 G types and 20 P types have been identified to date among rotavirus strains of both human and animal origin [2, 15]. In this context, 10 G types and 11 P Acknowledgements J.M.M. and A.D.S. are founder members of the African Rotavirus Network (ARN). N.M.K. and J.O.N. are members of the African Rotavirus Network. None of the authors have associations that could pose conflicts of interest. The results of this study were presented at the Virology Africa symposium held on November 8–11, 2005 in Cape Town, South Africa. We acknowledge support from World Health Organization and the African Rotavirus Surveillance Network. Correspondence: Dr Jason M. Mwenda, Institute of Primate Research, P.O. Box 24481-00502, Karen, Nairobi, Kenya. Tel.: þ254-020-882571-4; Fax: þ254-020-882546; E-mail <jmmathiu@yahoo.co.uk>. ß The Author [2008]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org 1 of 5 doi:10.1093/tropej/fmn052 Journal of Tropical Pediatrics Advance Access published July 1, 2008