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Measles
Virus (Rubeola)
The information provided is offered as a resource for Wisconsin Laboratories and Health Care Facilities
Note (4/11/2008): During the current Measles outbreak, testing and transport of specimens for Measles will be provided at no cost to the submitter.
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Submit the following specimens to the WSLH:
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Throat swab and nasopharyngeal swab, combined in the same vial of viral transport medium for Measles PCR
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Urine, submitted in an empty, sterile, screw-capped container (no additives)
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Serum for Measles IgM (if patient has a rash); a second serum may be required.
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Request WSLH test # 3214 for Measles PCR and WSLH test # 2814 for Measles IgM testing. Test results will be available within 24 hours of receipt at the Wisconsin State Laboratory of Hygiene.
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When submitting specimens to the WSLH for Measles testing, include a completed requisition form (CDD form A or B). If you do not have a WSLH requisition form available, you may substitute the "General Outbreak" form available at General Outbreak Response Form. Be sure to complete the submitter information, along with complete patient information, and the agent and test requested.
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Transport is available from Dunham Express at no cost to the submitter when you tell them to bill to WSLH account # 7263.
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NOTE: If sending specimens on a Friday, you must specify “Saturday delivery” or specimens will not be received at the WSLH until Monday.
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Specimens should be packaged with refrigerant packs following regulatory requirements.
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Guidance
- All suspected cases of measles should be immediately reported to the local public health department.
- Following CDC guidelines, the Wisconsin State Laboratory of Hygiene (WSLH) recommends collection of specimens for serologic and culture and real-time polymerase chain reaction (PCR) testing for all suspect cases of measles.
- The WSLH will perform IgM serology on the acute serum and will perform measles PCR testing of aliquots of combined nasopharyngeal/throat swab and urine specimens.
- The WSLH may perform culture and/or PCR for other agents that can cause similar symptoms.
- An aliquot of urine and combined nasopharyngeal/throat swab specimens will be forwarded to CDC for culture and characterization as appropriate.
- Specimens for culture and PCR testing should be collected at the same time as the acute serum for measles IgM serology.
- A repeat serum for measles IgM antibody should be collected if the first serum was collected within three days of rash onset and is negative for IgM antibody to measles.
- Negative results do not rule out Measles infection due to the following:
- The amount of virus shed at the time of sample collection may have been too low to be detected.
- Inadequate specimen collection, processing, shipping or storage can also significantly reduce the likelihood of detecting Measles virus or Measles RNA.
- Measles IgM antibody may be transient or undetectable in previously vaccinated individuals.
Measles Testing at the WSLH
- PCR
- Results of measles PCR testing are available within 24 hours of specimen receipt at the WSLH.
- Culture
- Isolation of measles virus is not recommended as a routine method to diagnose measles, but virus isolates are extremely important for molecular epidemiologic surveillance to help determine the geographic origin of the virus and the viral strains circulating in the United States.
- The WSLH will forward aliquots of appropriate specimens to the CDC for measles culture.
- Specimens for virus culture should be collected at the same time as samples taken for serologic testing. Specimens for culture should be collected within 10 days (preferably within 3 days) of rash onset.
- Measles virus can be isolated from urine, nasopharyngeal aspirates/swabs, or throat swabs.
- Serology
- IgM Serology
- Test results of serum specimens submitted to the WSLH for Measles IgM serology will be available within 24 hours of receipt of the specimen at the WSLH.
- Previously vaccinated individuals may not have a detectable IgM response. Therefore, the full clinical and epidemiologic picture should be taken into consideration when interpreting test results.
- If IgM serology is negative for specimens collected within 72 hours of rash onset, a repeat specimen should be collected and tested.
- IgG Serology
- Immune status
- Measles IgG serology can be performed at the WSLH on a single serum to assess an individual’s immune status for Measles.
- Diagnostic Testing
- Measles IgG serology of paired sera is available at the CDC. The WSLH will forward aliquots of appropriate specimens to CDC for testing.
- Measles IgG serology of paired sera is not recommended for diagnostic testing of previously vaccinated individuals.
- Measles IgG serology of paired sera can be of value for patients with no history of vaccination or with seronegative acute specimens. Collect acute serum as soon after onset as possible and collect the convalescent serum 2-3 weeks later to determine if a significant rise in IgG antibody titer has occurred.
Specimen Collection and Submission
Collect specimens for Measles testing as follows:
- Throat AND Nasopharyneal swabs
- WSLH recommends collection of a throat swab AND a nasopharyngeal swab, combined in the same vial of virus transport medium.
- Collect specimens as soon as measles is suspected, preferably within the first 3 days of illness, but no later than 10 days after rash onset.
- Synthetic swabs (e.g., Dacron) are preferred over cotton swabs, which may be inhibitory to enzymes used in PCR. Do not use calcium alginate swabs.
- Place both swabs in a single tube of virus transport medium; any commercially available virus transport medium is acceptable.
- Maintain specimen at refrigerator temperature prior to transport. Transport using kool-packs.
- Urine Samples
- Collect 10-50 ml of urine in an empty container; do not add virus transport medium.
- First-voided morning urine usually contains the highest concentration of infected cells. Virus can be present in the urine even a few days before rash appears and begins to diminish a few days following rash onset.
- Maintain the urine specimen at refrigerator temperature prior to transport. Transport using kool-packs.
- Serum Samples
- IgM Serology
- Collect 7-10 ml of blood in a red top or serum separator tube (SST). Store specimens at refrigerator temperature. Transport using kool-packs.
- Serum specimens for IgM serology will be tested at the WSLH within 24 hours of receipt of specimen.
- If IgM serology is negative for specimens collected within 72 hours of rash onset, a repeat specimen should be collected and tested.
- Previously vaccinated individuals may not have a detectable IgM response. Therefore, the full clinical and epidemiologic picture should be taken into consideration when interpreting test results.
Forms
- When submitting specimens to the WSLH for Measles testing, include a completed requisition form (CDD form A or B). If you do not have a WSLH requisition form available, you may substitute the "General Outbreak" form available at this link:
- Be sure to complete the submitter information, along with complete patient information, and the agent and test requested.
Shipping
- Patient specimens or isolates for Measles testing can be packaged and transported as "Category B Biological Substances".
- Specimens should be maintained at refrigerator temperature before and during transport.
Resources
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