TABLE 3.

Use of assays to determine diagnosis

Diagnosis	Result by RT-PCRa
	B. per- tussis	B. para- pertussis	Internal control
B. pertussis	Pos	Neg	Pos
B. holmesii or coinfectionb	Pos	Pos	Pos
B. parapertussis	Neg	Pos	Pos
Valid result, negative for B. pertussis, B. parapertussis, and B. holmesii	Neg	Neg	Pos
Inhibition or invalid extraction— test needs to be repeated	Neg	Neg	Neg

^aRT-PCR, real-time PCR; Pos, positive; Neg, negative.

^bDifferentiation by Sequencing of real-time PCR product.