An early detection of decline in rotavirus cases during the 2013/2014 season in Japan as revealed by time-series analysis of national surveillance data

ABSTRACT

Rotavirus is a leading cause of severe acutegastroenteritis in children worldwide, and globally licensed vaccines areavailable. To expedite the introduction of rotavirus vaccines in the nationalimmunisation programme, a simple, economical method to monitor changes in theburden of rotavirus disease may be of great help. Here, we report anapplication of a time-seriesanalysis on a publicly-available dataset in Japan on the weekly number oflaboratory-confirmed rotavirus-positive samples over the last 5 year period betweenthe 36th week of 2009 and the 35th week of 2014 during which rotavirus vaccines became marketed in Japan andpresumed to reach an uptake rate of at least 39% as a national average. Comparedwith the expected number of rotavirus detection based on the preceding four rotavirusseasons, the number of rotavirus detection during the 2013-2014 season was 43%(95% CI 38.6, 47.8). This suggeststhat the use of rotavirus vaccine had a positive impact on reducing the burdenof rotavirus diarrhoea in Japan. This method, because of its simplicity andlittle cost, should be applicable to early detection of the impact of rotavirusvaccine even in resource-poor countries where the World Health Organizationfunded and implemented the sentinel surveillance programmes oflaboratory-confirmed rotavirus cases.