Specimen Collection

Determining who has pertussis can be difficult. Whenever possible, a nasopharyngeal (NP) swab or aspirate should be obtained from all persons with suspected cases. A properly obtained NP swab or aspirate is essential for optimal results (see Figures 1 & 2).

If culture is planned, once an NP swab has been collected it should be directly plated or immediately placed into transport medium. NP aspirates should be dispensed and plated within 24 hours of collection. The same specimen can be used both for culture and polymerase chain reaction (PCR). With PCR, the most rapid test, the specimen should ideally be collected during the first 3 weeks of illness, but may provide accurate results for up to 4 weeks. Culture has better specificity, but takes up to 7 days to obtain results and the specimen ideally should be collected during the first 2 weeks of illness.

Key Resource

Best Practices for Healthcare Professionals on the Use of Polymerase Chain Reaction (PCR) for Diagnosing Pertussis

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Proper Technique for Obtaining a Nasopharyngeal Specimen for Isolation of Bordetella pertussis

Figure 1

Image: Manual for the Surveillance of Vaccine-Preventable Diseases, 2015

Figure 2

Image: Courtesy of CDC