Virus Culture/Isolation/Identification

The Oregon State Public Health Laboratory (OSPHL) provides viral testing for providers attending patients with illnesses of suspected viral etiology. These tests are intended to assist providers by confirming or ruling out viral illness. They also serve to identify particular viruses which may be prevalent in the state. Both serological testing and virus isolation are performed. However, due to financial limitations, OSPHL does not accept specimens for routine culture and isolation of oral or genital herpes.

NP/Throat swabs, stool specimens, cerebrospinal fluids, lesion swabs, body fluids and tissues may be submitted for virus isolation. Use the special virus isolation kit provided by the OSPHL or commercial viral transport media with an OSPHL request form. Do not use wooden swabs, wood applicator/tongue depressors, or calcium alginate swabs to collect or transfer virus specimens as they are toxic to viruses.

Collect specimen(s) as soon as possible after onset of symptoms to increase the likelihood of isolating a virus. Optimal time for collecting NP/Throat swabs, cerebrospinal fluid, and stool specimens is during the first three to four days of illness. Specimens collected more than seven days after onset of symptoms are less likely to yield a viral isolate. It is difficult, if not impossible to isolate viruses from specimens that are improperly collected or transported.

Collection Instructions

NOTE: Do not freeze specimens for respiratory syncytial virus (RSV), varicella zoster (VZV), or cytomegalovirus (CMV). See special instructions for CMV at the end of this section.

1. Cerebrospinal Fluid (CSF)

Submit CSF in a sterile tube sealed tightly. Ship frozen on dry ice, or unfrozen, with ice packs.

2. Lesion Swabs

Swab the lesion thoroughly. Place swab in viral transport media.

3. Other Body Fluids

Submit all other body fluids (except blood which is not cultured for virus by OSPHL) in a tightly sealed sterile tube, labeled with the patient's name, the specimen type, and the date collected. Transport on cold packs.

4. Stool Specimens

Use only containers with screw cap lids for transport to the OSPHL. Use spoon to transfer a portion of the specimen to the screw-capped bottle. Do not fill the container more than 1/2 full to minimize leakage. Screw cap on tightly and tape. Dispose of box, spoon, and remaining specimen in a safe manner. NOTE: Stool specimen bottle for virus isolation contains no fluid.

5. Tissue - Autopsy or Biopsy

Collect tissue aseptically, using a separate set of instruments for each tissue. Send a representative sample of all infected organs, preferably frozen ( do not freeze if cytomegalovirus, varicella zoster virus, or respiratory syncytial virus is suspected ), in separate, sterile, screw-capped containers. Ship on dry ice.

Shipping Instructions

1. Close specimen containers tightly.
2. Fill out request form completely and package specimen appropriately.

3. Transport specimen promptly on dry ice if frozen or on cold pack if unfrozen. Keep specimen refrigerated prior to shipment. If specimens must be held for longer than 24 hours, freeze, preferably at -70 ^oC, and ship on dry ice. Do not freeze specimens which may contain CMV, RSV, or VZV.

4. Specimens must be packaged with enough absorbent material to contain and absorb all liquid if leakage or breakage should occur in shipment. Specimens with insufficient postage, breakage or leakage in transit will not be accepted.
Reporting

A preliminary report is made when either a virus has been isolated or a culture has been observed for two weeks. A final report is issued when when the virus is identified, or after 30 days, to allow slow-growing viruses such as CMV and VZV time to appear, if present.

Interpretation

No Virus Isolated:

On a Preliminary Report this result indicates that no virus has been isolated in the first 10 days of culture. On a Final Report it indicates that no virus was isolated over the entire course of the test. A report of "No Virus Isolated" does not rule out the possibility of a viral infection -- it merely indicates that no virus was observed in the specimen submitted. Improper specimen handling, transport, and storage may contribute to a "false" negative result.

Virus Isolated:

This result will be followed by the name of the organism isolated (e.g., "Influenza A isolated"). Exceptions are as follows:

• Herpes Simplex is not reported as Type 1 or Type 2.
• Enteroviruses may be identified only as far as family (e.g., "Coxsackievirus isolated").