Influence of herd immunity on norovirus: a long-term field study of repeated viral gastroenteritis outbreaks at the same facilities

Table 5 Average interval between outbreaks by the same genotype at the same facility

	Number of combination	Interval between outbreaks (Month)
	Number of combination	Average	Maximum	Minimum
Total	49	31.2	90	0
Genotype
GI.3	2	4.0	7	1
GII.2	13	43.2	90	0
GII.3	5	47.2	75	1
GII.4	20	18.6	47	0
GII.6	6	41.2	67	2
GII.14	3	35.0	51	6
Setting^a
K/Ns	17	36.4	83	0
PSs	20	35.7	90	0
NHs	11	16.8	40	0
Hospital	1	13	–	–

^aK/Ns: Kindergarten/nursery schools; PSs: Primary schools; NHs: Nursing homes for the aged

ISSN: 1471-2334