Specimen Collection and Testing for Influenza A Variant Viruses H3N2v and H1N2v - Minnesota Dept. of Health

Specimen Collection and Testing for
Influenza A Variant Viruses

MDH is continuing to ask for specimens from all inpatients with illness compatible with influenza* and outpatients with illness compatible with influenza who meet any of the following criteria:

  • Direct or in-direct exposure to swine within 7 days of illness onset
  • Attendance at an agricultural event (e.g., county fair) where swine were present within 7 days of illness onset
  • Contact with a confirmed case of variant or swine influenza (which may include H3N2v, H1N2v and H1N1v) within 7 days of symptom onset

*Illness compatible with influenza may present as influenza-like illness (ILI) [fever ≥ 100°F plus cough and sore throat]. Note that influenza may not cause fever in all patients (especially in patients < 5 years of age, ≥ 65 years of age, or patients with suppression of their immune system).

Appropriate Specimen Types

For patients admitted with ILI or clinical suspicion of influenza without evidence of pneumonia or other lower respiratory disease – submit one upper respiratory specimen per patient.

  • Nasopharyngeal swab is the preferred specimen
  • Other acceptable specimens include; nasal swab, nasal wash/aspirate, throat swab, or combined nasal swab with an oropharyngeal swab, and viral culture

Specimen Collection

  • Place swab in Viral Transport Media (VTM; e.g. M4, M5, Hanks) for transport to MDH. If VTM is not available, then sterile saline or phosphate buffered saline (PBS) is acceptable.
    • Specimens transported in VTM must reach MDH within 7 days of collection
    • Specimens not transported in VTM must reach MDH within 5 days of collection
  • If sending leftover saline solution (no other chemicals, preservatives) from rapid testing, you must send at least 500 µl.
  • Swabs collected and/or transported in non-sterile containers, baggies, or without transport media (dry) will not be accepted.
  • Ship at refrigeration temperature.

  • Collection of Nasopharyngeal Specimens with the Swab Technique. (Video-New England Journal of Medicine)

Specimen Submission Forms

Please indicate "swine exposure" as appropriate.

Only a single Clinical Testing and Submission Form is required, however, you must use the correct version of the form, which is dependent on whether the patient is hospitalized or not.
NOTE: There is NO fee sticker required for influenza testing.

Non-Hospitalized Influenza Testing (Project #493)
Use this form for submitting specimens for influenza testing from non-hospitalized patients. Write project #493 in the upper right hand corner of the form and indicate "swine exposure" as appropriate.

Hospitalized Patients Only (Project #1492)
Use this form for all specimens submitted from persons hospitalized with ILI or clinical suspicion of influenza. In order to allow for prompt testing of submitted specimens for project #1492, please be sure to fill out the form completely, especially information regarding hospitalization (date of admission, hospital of admission, and outcome) found on the lower right hand corner of the form, and indicate "swine exposure" as appropriate.

Shipping to MDH-PHL

  • Ship at refrigeration temperature.
    • Use cold packs to keep specimens at 4 degrees C.
  • Ship specimens to MDH-PHL by an overnight delivery service.
    • NOTE: It is the responsibility of the submitting laboratory to determine the appropriate packaging and shipping for patient specimens and culture isolates.
    • DOT HAZMAT regulations: PHMSA Regulations
  • Ship to:
    Minnesota Department of Health
    Public Health Laboratory
    Attn: Biological Accessioning
    601 Robert St. N
    St. Paul, Minnesota 55155-2531


Updated Monday, April 09, 2018 at 10:40AM