Surveillance of rotavirus in three hospital settings of Sri Lanka 2007 - 2010

Abstract

INTRODUCTION: Rotavirus is an important aetiological agent of childhood diarrhoeas in Sri Lanka. OBJECTIVES: To study the rotavirus epidemiology and genotypic diversity of cases hospitalized in three geographical locations of Sri Lanka, Ragama, Galle and Kandy. MATERIALS AND METHODS: The study was approved by the ethical review board of the Sri Lanka College of Paediatricians. Stool samples were collected from children < 5 years, hospitalized at the Teaching Hospitals at Ragama (RTH) (November 2007 - October 2010) Galle (GTH) and Kandy (KTH) (mid and late 2008) respectively for acute gastroenteritis. Rotavirus was detected using EIA kit, Rotaclone®. A subset of rotavirus positive samples was genotyped by reverse-transcription(Rt)-PCR and polyacrylamide-gel-electrophoresis (PAGE). RESULTS: Stool samples of 1245 children (69.2%, 23.3% and 7.3% from RTH, GTH and KTH respectively) were screened for rotavirus. Of them, 476 were positive by EIA. The overall rate of prevalence of rotavirus infection was 38.2%. The median age of infection ranged from 13-20 months. Rotavirus genotyping was done on 375 (78.8 %) samples. G1 [P8] was the overall dominant strain (44.8%) followed by G9[P8] (10.1%), G2[P4] (5.3%), G3[P8] (3.2%), G1[P6] (2.1%), G12[P6] (1.3%), G2[P8] (1.06%) and 0.26% of G4[P6], G4[P4] and G4[P8]. The G or P serotype was untypable in 25.6% of samples and 5.6% were of mixed-G and P type. PAGE yeilded 25 electropherotypes (E1-E12 and E16-E29), with E5 and E20 causing 19 and 14 percent of infections respectively. The electropherotype could not be determined in 26%. CONCLUSIONS: Rotavirus continues to be an important cause of childhood diarrhoreas in Sri Lanka. Strain G1P8 predominated in all areas during the surveillance period with a notable percentage of mixed-G and P infections. Multiple E types identified indicate increasing strain diversity