Table 4.2.

Distribution of common viruses causing human gastroenteritis

	Brandt et al1983	Nguyen 2007	Li 2009
Place of study	Washington	Vietnam	Hong Kong
Time period of study	1974–1982	2002–2003	January–August 2008
Population	Pediatric	Pediatric	Pediatric
Norovirus	_a	5.5 %	23 %
Rotavirus	34.5%	67.4 %	28 %
Enteric Adenovirus	4.7%	3.2 %	3 %
Astrovirus	_a	0.6 %	0.6 %
Sapovirus	_a	0.8 %	0
Mixed viruses	40.1%	5.5 %	0.4 %
Unexplained viruses	19.1%

^aThese viruses were not known till 1982