Is there a test for measles (Measles, also known as Laboratory test for Measles virus)?

From the Guidelines

Yes, there are tests available to diagnose measles, including blood tests that detect measles antibodies (IgM and IgG) and RNA detection using polymerase chain reaction (PCR) testing. The most common diagnostic test is a blood test that detects measles antibodies in a person's blood 1. Healthcare providers can also collect samples from the throat, nasal passages, or urine to identify the measles virus through RNA detection using PCR testing. Additionally, viral cultures can be performed, though these take longer to yield results.

Key Points to Consider

• Testing is typically ordered when a person shows characteristic symptoms of measles, including high fever, cough, runny nose, red eyes, and a distinctive rash that spreads from the face to the rest of the body.
• Early testing is important because measles is highly contagious, and prompt diagnosis helps prevent further transmission.
• If you suspect measles, you should contact a healthcare provider immediately rather than visiting a medical facility unannounced, as special isolation precautions may be needed to prevent exposing others.
• The timing of specimen collection in relation to rash onset is crucial for interpreting serologic data, and measles IgM may be detectable at the time of rash onset, peaks approximately 10 days after rash onset, and is usually undetectable 30-60 days after rash onset 1.
• Measles can be severe and prolonged among immunocompromised persons, particularly those who have certain leukemias, lymphomas, or human immunodeficiency virus (HIV) infection, and may occur without the typical rash 1.

From the Research

Laboratory Tests for Measles

• Laboratory diagnosis of measles relies largely on the detection of specific IgM antibodies in serum, dried blood spots, or oral fluid, or the detection of viral RNA in throat or nasopharyngeal swabs, urine, or oral fluid 2.
• Measles IgG avidity assays can determine the overall strength of molecular binding between measles-specific IgG antibodies and measles virus antigens, and can distinguish recent from distant measles virus infections 3.
• The plaque reduction neutralization test (PRNT) and the enzyme-linked immunosorbent assay (ELISA) are both widely used to assess immunity to infectious diseases such as measles, but they use two different measurement principles 4.
• Focus reduction neutralization test (FRNT) is a faster and more specific assay than PRNT, and is extremely useful when immunity to measles virus needs to be assessed in patients with a specific medical condition 4.
• Commercial immunoassays for detection of measles-specific IgG can have varying performance characteristics, and false-negative test results may lead to unnecessary quarantine and exclusion from activities, while false-positive results may fail to identify susceptible individuals 5.

Types of Laboratory Tests

• IgM antibody detection in serum, dried blood spots, or oral fluid 2.
• Viral RNA detection in throat or nasopharyngeal swabs, urine, or oral fluid 2.
• Measles IgG avidity assays 3.
• Plaque reduction neutralization test (PRNT) 4.
• Focus reduction neutralization test (FRNT) 4.
• Commercial immunoassays for detection of measles-specific IgG 5.