Surveillance of Rotavirus Gastroenteritis (2015-2017): Epidemiology and Circulating Rotavirus Genotypes in Pre-rotavirus Vaccine Introduction Period in Myanmar

A hospital-based prospective active surveillance for rotavirus gastroenteritis (RVGE) was conducted among hospitalised acute gastroenteritis (AGE) patients to identify the infecting rotavirus strains and to provide epidemiological information on RVGE in Myanmar. Stool samples were collected from children less than 5 years old admitted to Yangon Children’s Hospital (YCH) for AGE during January 2015 to September 2017. Collected stool samples were screened for rotavirus antigen by ELISA and genotyped by reverse transcription polymerase chain reaction (RT-PCR). Overall, 48.8% (1,167/2,393) of samples were ELISA positive for rotavirus and the most affected were children aged 6-23 months, 81.9% (956/1,167). RVGE occurred in a seasonal cycle with peak detection in the cold and dry months (November to February). As compared with non-RVGE, RVGE cases had significant higher percentage of vomiting (84.5% versus 73.0%; P<0.05), fever (80.1% versus 71.8%; P<0.05) and severe clinical scoring (79.4% versus 67.5%; P<0.05). Genotyping revealed that G9P[8] was predominant in the year 2015 (53.3%) and 2016 (30.9%), but it was replaced in 2017  by G3P[8] (58.2%). Information from this surveillance not only highlights facts for consideration of rotavirus vaccine introduction plan in pre-vaccination era, but also provides vital baseline data for post-vaccination monitoring of vaccine impact and effectiveness.