Table 2. Association between Cp value and recovery in culture, for samples positive for IS481 (a) and IS1001 (b).

a	Cp value IS481	PCR positive	Culture positive (B. pertussis)	Recovery culture/PCR
	Cp ≤ 20	165	133	80.6%
	20 < Cp ≤ 25	122	81	66.4%
	25 < Cp ≤ 30	227	89	39.2%
	Cp > 30	675	39	5.8%
	Total	1189	342	28.8%
b	Cp value IS1001	PCR positive	Culture positive (B. parapertussis)	Recovery culture/PCR
	Cp ≤ 20	7	7	100.0%
	20 < Cp ≤ 25	16	13	81.3%
	25 < Cp ≤ 30	22	14	63.6%
	Cp > 30	105	11	10.5%
	Total	151	45	29.8%