Clinical Specimens

Clinical specimens for viral isolation are often helpful to confirm a positive serum result and for viral surveillance of rubella genotypes.

Clinical Specimens: Throat Swab
Specimen type: Throat swab (Oropharyngeal swab). This is the preferred sample for rubella virus.
Collection procedure: Use a cotton/dacron swabs to collect the specimen. Swab the posterior pharynx and tonsillar areas, avoiding the tongue (tongue depressor may be helpful). The mucosa behind the uvula and between the tonsils should be gently swabbed with a back-and-forth motion. Keeping swabs moist after collection is most important (see transportation below).
Optimum collection time: Collect at first contact. Virus can usually be detected 2-3 days before rash and up to about 14 days post rash. The optimal timing for virus isolation is day of rash through day 5 post rash.
Transportation container: Place swab in 3-4 ml Viral Transport Media (VTM). Any sterile isotonic fluid, like phosphate buffered saline (PBS) or common tissue culture medium like Eagle’s MEM can be used. Swabs may be broken off and shipped with media. Alternatively, swirl/agitate the swab in the media for several minutes before removal.
Commercially available kits containing swabs and viral transport media are acceptable.
Volume: 3-4 ml of VTM.
Transport: Cold, with ice packs. Should be received at the lab within 48 hours of collection. If shipment is delayed and facilities are available, the specimens should be frozen at –70 C and shipped on dry ice. Otherwise, store specimens in refrigerator (freezing at -20 C reduces viability of virus).
Clinical Specimens: Nasopharyngeal Swab
Specimen type: Nasopharyngeal (NP) swab. An NP swab can be collected in addition to a throat swab or can serve as an alternative specimen for infants with CRS. The NP swab can also be pooled with a throat swab or shipped separately.
Collection procedure: Use a cotton/dacron swab to collect the specimen. Insert sterile swab into nasopharynx, rotate and remove. Keeping swabs moist after collection is most important (see transportation below.)
Transportation container: Place swab in 3-4 ml Viral Transport Media (VTM). Any sterile isotonic fluid, like phosphate buffered saline (PBS) or common tissue medium like Eagle’s MEM can be used. Swabs may be broken off and shipped with media. Alternatively, swirl/agitate the swab in the media for several minutes before removal. Commercially available kits containing swabs and viral transport media are acceptable
Volume: 3-4 ml of VTM.
Transport: As above for oropharyngeal specimens.
Clinical Specimens: Urine
Specimen type: Urine. (Throat or NP specimens have higher rate of rubella virus recovery than urine.)
Collection procedure: Collect clean void, first morning if possible.
Optimum collection time: As above.
Transportation container: Sterile plastic leak-proof container.
Volume: 10ml
Transport: Cold, on ice packs.

CDC accepts specimens from state public health laboratories and other federal agencies for analysis. Specimens from private healthcare providers and institutions must be submitted to the local state health department laboratory (state, county, city) for appropriate processing.

Note that specimens sent for testing must be accompanied by a completed Specimen Submission Form. For instructions on packing and shipping, see Shipping Specimens to CDC.

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