Noroviruses were only assayed in 2001; Enteroviruses were assayed in all years; Adenoviruses were assayed in 2002 and 2003 (positive results were only obtained in 2003).
Noroviruses were only assayed in 2001; Enteroviruses were assayed in all years; Adenoviruses were assayed in 2002 and 2003 (positive results were onlyobtained in 2003).