Whooping Cough (Culture)

Test information: The isolation of Bordetella pertussis, Bordetella parapertussis. Where applicable to determine antimicrobial susceptibility results.

Availability: Available locally during routine hours: 08:45 - 17:15.

Turnaround Time: 7 Days (Culture)

Related Tests:

• Bordetella pertussis Antibody
• Routine Respiratory PCR

Specimen Type(s)

• Pernasal Swab;
• Swab;

Other Acceptable Specimen Type(s)

N/A

Specimen Container - Adult

• Sterile CE-marked Charcoal swab in Transport medium (Narrow bud);

Specimen Container - Paediatric

• Sterile CE-marked Pernasal Swab (Narrow bud);

Analytes

• Culture & Sensitivity;

Part of a test profile?

No

Volume (min) of sample to be sent to laboratory

N/A

Patient Preparation, Sample Handling and Transport

• Sample before antimicrobial therapy where possible.
• It is best to obtain a culture from nasopharyngeal specimens collected during the first
• 2 weeks of cough. This is when viable bacteria are still present in the nasopharynx.
• A per-nasal swab is inserted through a nostril and advanced along the floor of the nose until it reaches the nasopharynx. It has been suggested that the swab is held against the posterior nasopharynx for up to 30 seconds or until the patient coughs. In practice, it is more likely that a patient will only be able to tolerate this for a few seconds.
• Specimens should be transported to the laboratory without delay during normal working hours. B. pertussis and B. parapertussis are delicate organisms and therefore, processing delays may affect the likelihood of a positive culture.
• Sensitivity is also highly dependent on specimen quality and is affected by increasing patient age, vaccination status and length of illness.
• If transport is delayed store at 2-8 °C.
• The swab must arrive in the laboratory within 48 hours of being taken.

Maximum add on time

N/A

Units and Reference Ranges / Interpretation

Susceptibility Testing: Each susceptibility category is defined by breakpoints specific for each species and agent. The breakpoints are minimum inhibitory concentrations (MIC) and describe the amount of agent required to inhibit the growth of the organism.

The definitions of (S),(I), and (R) emphasize the close relationship between the susceptibility of the organism and the exposure of the organism at the site of infection.

Susceptible (S): High likelihood of therapeutic success with standard dosing.
Susceptible Increased Exposure (I): High likelihood of therapeutic success with increased dosing.
Resistant (R): High likelihood of therapeutic failure.

UKAS number

8869

UKAS accredited test?

Yes

Comments

• Cultures are unlikely to be positive in adolescents and adults with more than 3 weeks of coughing.
• It is also more difficult to recover the organism in vaccinated compared with unvaccinated children.
• Given the limitations of culture methods, it is important to emphasise that a negative culture does not exclude pertussis.
• Serology may be helpful to confirm the diagnosis of whooping cough in patients with cough duration of more than 2 to 3 weeks, when culture is unlikely to yield positive results.

Useful Links:

• Adult Antimicrobial Guide
• Paediatric Antimicrobial Guide
• Primary Care Antibiotic Guide

If you have any queries about a test or results interpretation please contact us.