Page 207 - pathology_services_handbook_5th_edition_2018

Note:
1. Submitted primarily for detection of MRSA carriers.
2. For other indications, please state relevant clinical history.

2. Pernasal swab/nasopharyngeal swab/aspirate MICROBIOLOGY

This is done to isolate Bordetella pertussis for the diagnosis of pertussis (whooping
cough).

i. A pernasal swab (Dacron or rayon with flexible ultrafine wire shaft) is inserted
through a nostril and advanced along the floor of the nose until it reaches the
nasopharynx.
ii. Leave the swab at the posterior nasopharynx for up to 30 % or until the patient
coughs.
iii. Then, slowly withdrawn the swab with a rotating motion.
iv. For culture, directly inoculate the swab onto Charcoal agar.
v. For PCR, place the Dacron/rayon swab into Stuart Transport Media.

Note:
• To get charcoal agar and Dacron/rayon swab from bacteriology laboratory
before taking sample.
• Write relevant clinical history on the request form eg: suspect pertussis/
whooping cough.
• It is compulsory to inform microbiologist staff of the suspected case before
taking specimen.

2.1 Nasopharyngeal aspirate

a) Vacuum-assisted nasopharyngeal aspirate method

• Attach mucus trap to suction outlet and catheter. Turn on suction and adjust to
suggested pressure.
• Without applying suction, insert catheter into the nose directly posteriorly as
far as nasopharynx.
• Apply suction using a rotating movement, slowly withdrawn catheter.
• Repeating procedure for the second nostril will deliver optimal combined
sample.
• Transport specimen to the laboratory immediately.

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