Laboratory Information

Refer to Measles Testing at the Arizona State Public Health Laboratory for information on collection, storage, and transport of specimens for measles testing.

Lab Reporting Requirements

The Lab Reporting Requirements outline information necessary for reporting pathogens and laboratory tests to the Arizona Department of Health Services.

Specimen Collection

Nasopharyngeal swabs are generally the preferred sample for detection of the virus. Only Dacron swabs should be used for measles testing. Urine samples may also contain the virus and when feasible to do so, collection of both respiratory and urine samples may increase the likelihood of detecting virus. Blood samples may also be used to detect antibodies to the measles virus.

Measles virus isolation is most successful when samples are collected on the first day of rash through 3 days following onset of rash; however, it may be possible to detect virus in specimens collected up to 7 days following rash onset.

Storage of Specimens

Measles virus is sensitive to heat and desiccation. The viability decreases markedly when samples are not kept cold. It is important to transport samples with cold packs as soon as possible following sample collection. Avoid repeat freeze-thaw cycles or freezing at -20°C (standard freezer temp). If a specimen cannot be shipped immediately, it is generally preferred that the sample be kept in the refrigerator (4°C) before shipping. Freezing specimens may delay test results, as the specimen must be thawed prior to testing.

  • Respiratory Samples - Specimens can be refrigerated and kept at 4°C until shipment. Ideally, specimens should be shipped as soon as possible. Dacron nasopharyngeal swabs that are in very little fluid (1-4ml) may be frozen at -70°C if necessary.
  • Urine Samples - Measles virus may be present in the cells that have been sloughed off in the urinary tract. Virus can be present in the urine even a few days before rash appears and begins to diminish a few days following rash. For optimal virus preservation, centrifuge 10-50ml of urine and re-suspend the sediment in 2-3 ml of sterile transport medium, tissue culture medium or physiological buffered saline. Freeze the re-suspended urine sample at -70° C or keep the urine sample at 4° C and ship on cold packs as soon as possible to a laboratory that is able to perform viral isolation.
  • Blood Samples - Serum should be collect 2-28 days after rash onset. Specimens should be shipped refrigerated with cold packs but not frozen.

Refer to the Instructions for Collecting Nasopharyngeal Swab Specimens guide for detailed nasopharyngeal swab specimen collection instructions.

Lab Criteria for Diagnosis

A case is considered to be laboratory confirmed if it is positive for measles IgM antibodies or is positive for Measles virus upon PCR or viral culture.

Isolate Submission to the Arizona State Public Health Laboratory

The Arizona Administrative Code, R9-6-204, requires that all clinical and reference laboratories submit a positive Measles culture or IgM serologic result to the Arizona State Public Health Laboratory for confirmatory testing. After confirmatory testing, the specimen is forwarded to the Centers for Disease Control and Prevention (CDC) for additional testing and genotyping if possible.

Guide to Laboratory Services

Refer to the Guide to Laboratory Services: Microbiology for detailed specimen collection instructions.

Microbiology Submission Form

The Arizona State Health Laboratory's Microbiology Submission Form must be submitted with each specimen. The fields that are required for specimen processing include: Patient first and last name, age, sex, submitting agency name, specimen collection date, and specimen type. Before submitting specimens, be sure to notify your local health department to coordinate specimen collection and submission.

Shipping Details

Specimens should be mailed to:

Bureau of State Laboratory Services
250 N. 17th Avenue
Phoenix, AZ 85007-3231
Fax Number: (602) 542 - 1188