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Department of Health Services

Public Health Regional Laboratory

Novel Coronavirus (SARS-coV-2; COVID-19)

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Ordering

Testing at the Sonoma County Public Health Lab is only available with Disease Control approval. Once approved, contact the lab at (707) 565-4711 to set up electronic ordering via our web portal.

Methodology

RT-PCR

CPT Code

87798

Acceptable Specimens

Use only synthetic fiber swabs with plastic shafts. Do not use calcium alginate swabs or swabs with wooden shafts, as they may contain substances that inactivate some viruses and inhibit PCR testing. Place swabs immediately into sterile tubes containing 2-3 ml of viral transport media. 

Nasopharyngeal swab: Insert a swab into the nostril parallel to the palate. Leave the swab in place for a few seconds to absorb secretions. Swab both nasopharyngeal areas with the same swab.

NP/OP combined swabs: Both a nasopharyngeal (NP) swab AND oropharyngeal (OP) swab in a SINGLE, COMBINED viral/universal transport medium.

Oropharyngeal swab (e.g., throat swab): Swab the posterior pharynx, avoiding the tongue. 

Nasal swab (Anterior nares): Collected by a healthcare provider or by a supervised onsite self-collection.  Using a flocked or spun polyester swab, insert the swab at least 1 cm (0.5 inch) inside the nostril (naris) and firmly sample the nasal membrane by rotating the swab and leaving in place for 10 to 15 seconds. Sample both nostrils with same swab.

Nasal mid-turbinate swab: Collected by a healthcare provider or by a supervised onsite self-collection. Use a flocked tapered swab. Tilt patient’s head back 70 degrees. While gently rotating the swab, insert swab less than one inch (about 2 cm) into nostril (until resistance is met at turbinates). Rotate the swab several times against nasal wall and repeat in other nostril using the same swab.

Nasopharyngeal wash/aspirate or nasal aspirate:Collect 2-3 mL into a sterile, leak-proof, screw-cap sputum collection cup or sterile dry container. 

Sputum: Have the patient rinse the mouth with water and then expectorate deep cough sputum directly into a sterile, leak-proof, screw-cap sputum collection cup or sterile dry container.

Bronchoalveolar lavage, tracheal aspirate:Collect 2-3 mL into a sterile, leak-proof, screw-cap sputum collection cup or sterile dry container.

Specimen Storage and Transport

  • Refrigerate specimen at 2-8°C and ship same day or overnight to SCPHL on ice pack.
  • If specimens must be held for >72 hours, they should be promptly frozen at -70°C and shipped on dry ice.

Specimen Rejection

  • Leaking specimens
  • Unlabeled specimens
  • Incorrect swab
  • Incorrect transport media
  • Incorrect transport/storage temperature

Setup Days

Daily

Turn-around-time

8-72 hours (from time of receipt)

Lab Slip

Testing at the Sonoma County Public Health Lab is only available with Disease Control approval. Once approved, contact the lab at (707) 565-4711 to set up electronic ordering via our web portal.