Can cases and outbreaks of norovirus in children provide an early warning of seasonal norovirus infection: an analysis of nine seasons of surveillance data in England UK

Table 2 Spearman’s rank correlation, showing the relative temporal position of cases in children (0-15yrs) in relation to adults (≥ 16yrs) (by week)

Surveillance dataset	Lead time					Lag time
Surveillance dataset	+ 4 weeks	+ 3 weeks	+ 2 weeks	+ 1 week	Concurrent	-1 week	-2 weeks	-3 weeks	-4 weeks
Laboratory norovirus reports	0.75	0.78	0.80	0.80	0.75	0.67	0.58	0.48	0.40
NHS 111 calls for diarrhoea^c	0.68	0.66	0.64	0.69	0.64	0.39	0.20	0.10	0.02
NHS 111 calls for vomiting^c	0.62	0.71	0.76	0.78	0.73	0.58	0.48	0.41	0.37
GP consultations^ab	-0.09	-0.09	-0.30	-0.21	0.14	-0.03	-0.15	-0.01	-0.09

ISSN: 1471-2458