Table 4

Proportion of laboratory confirmed cases among primary (first) cases in families of pertussis cases in PICU and wards

Relationship	PICU	Ward	Total
Parent	10/11	2/3	12/14
Sibling	0/6	2/3	2/9
Baby or co-primary	6/8	2/2	8/10
Total	16/25	6/8	22/33