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Specimen Collection Manual: Nasopharyngeal (NP) Specimens

Instructions

Purpose

Proper collection of a nasopharyngeal swab is imperative to ensure an optimal specimen for detection of microbial pathogens within the nasopharynx.

Allowable Patients

NP swabs can be collected on adults and children greater than 24 months of age. NP specimens on infants less than 24 months old must be obtained by a physician or a nurse.

Safety

• When handling NP swab specimens, always handle as potentially hazardous and use Standard Precautions.
  1. When obtaining the specimen, wear gloves and a lab coat.
  2. If the patient is coughing, also wear a surgical mask and eye protection.
  3. Discard all contaminated materials in biohazard waste containers.
• Refer to the WBH Clinical Pathology Safety and Infection Control Manuals.

Materials

• Dacron or rayon-tipped nasopharyngeal swab with a flexible shaft (flocked swabs are acceptable).
• Transport media:
  • For viral or Chlamydia infections: UTM or UVT.
  • For bacterial infections: Amies transport media.
• Personal protective equipment (mask, gloves, eye protection, lab coat).
• Note: Cotton or calcium alginate swabs are not acceptable.

Viral Transport Medium

Preparation

1. The NP swab specimen must be placed into the correct transport media:
   • Viral Transport Medium (UTM, UVT).
     • Viral culture tests.
     • Chlamydia culture.
     • Molecular tests.
   • Bacterial Transport Medium: The E-swab contains liquid Amies transport medium for bacteria and fungi. The specimen must be collected with a mini-tip swab.
2. Specimens should be collected within the first 24-72 hours of the onset of symptoms and no later than 5 days after the onset of symptoms.
   • Collect up to two (2) samples from each patient with a respiratory-like illness.
   • Properly collected NP swabs are the optimal specimens.
   • NP swabs should be placed into standard container with a pre-dispensed amount (2-3 mL) of transport medium.
   • It is CRITICAL that the correct transport medium for the requested test(s) is used.
3. Label each container with the following:
   • Patient's name:
     • The patient's name must EXACTLY match that in the computer system or on the test requisition form.
   • Patient's date of birth.
   • Patient's MRN (if available).
   • Type of specimen (e.g., Nasopharyngeal, NP).

Specimen Collection Criteria

Procedure (Adults)

1. Obtain a nasopharyngeal swab.
2. Identify patient with two patient identifiers (i.e., name and birthdate).
3. Have the patient sit with head against a wall as patients have a tendency to pull away during this procedure.
4. Open the package.
5. Put of gloves, mask, and eye protection.
6. Measure the distance between the earlobe and the base of the nose. The swab should be inserted to 1/2 the distance of that measurement. It may help to mark the halfway point on the swab or bend it slightly.
7. Tilt patient's head back at a 70 degree angle (see diagrams below).
   
   
   
8. Slowly insert the swab into one nostril by gently passing the NP swab on a flexible wire straight back (not upwards) and continue along the floor of the nasal passage for several centimeters until reaching the nasopharynx (resistance will be met). A distinct feeling of resistance indicates that the posterior pharynx has been reached. Never force the swab. If obstruction is encountered before reaching the nasopharynx, remove swab and try the other nostril.
9. This may instinctively cause the patient to gag. Have a tissue ready for the patient to use if necessary.
10. Gently rotate the swab several times (5-10 seconds) across the surface to loosen epithelial cells.
11. Gently remove swab and immediately inoculate the appropriate transport media by inserting the swab at least 1/2 inch below the surface of the media. Bend or clip the wire swab handle to fit the transport medium tube and reattach the cap securely.
12. Label specimen and transport to the Microbiology Laboratory.

Older Children (2 years to 8 years, variable)

1. Have the child sit on their parent's lap, if necessary.
2. The patient should place one hand on the hands of the child and their other hand on the child's forehead.
3. The phlebotomist should place one hand on the child's chin and swab with the other, as described above.

Children younger than 4 years (Newborn to 4 years, variable)

1. If necessary, the phlebotomist may have the parent hold the child chest to chest, securing the child's arms.
2. The parent should have one hand on the child's head and one arm across their chest.
3. The phlebotomist should place one hand on the child's chin and swab with the other, as described above.

Preparation for Courier Transport

• Transport labeled specimens to the testing laboratory.
  • Viral tests: Put swab into UTM or UVT viral transport media.
    • Bend or clip the flexible shaft of the swab into the transport medium. OR
    • Break off swab at the perforation into the transport medium.
  • Bacterial or other non-viral culture testing:
    • Put swab into collection container.
    • Tightly cap the container for transport.
• Transport specimens immediately. If transport will be delayed for viral specimens, refrigerate (2-8°C or 36-46°F) specimen or place on wet ice.

Reference

1. BD Diagnostics, Sparks, Maryland. Nasopharyngeal Specimen Collection poster, February 2005.
2. Linscott, A.J., 2010. Specimen Collection, Transport, and Acceptability. Clinical Microbiology Procedures Handbook, Garcia, Lynne S., Editor in Chief, et al, 3^rd Edition. ASM Press, Washington, D.C., Section 2.1.

Contacts

Last Updated

3/8/2024