Measles (Rubeola) Antibodies, IgM

Serum

1 mL

0.5 mL (Note: This volume does not allow for repeat testing.)

Gel-barrier tube, red-top tube or serum transfer tube

Stability determined by manufacturer or literature reference.

This test is invaluable for determining acute-phase infection with the rubeola (measles) virus by detecting the presence of IgM antibodies. It also plays a crucial role in identifying individuals who are not immune to the virus, enabling timely preventive measures. By measuring IgM antibodies the molecular detection of virus, healthcare providers can accurately diagnose current infections and recognize those at risk, ensuring appropriate medical responses and public health interventions.

Measles is extremely contagious, especially among unvaccinated individuals, and spreads through direct contact with aerosolized droplets or respiratory secretions. Immunocompromised individuals, pregnant women and those with nutritional deficiencies face a higher risk of severe complications, such as pneumonia and central nervous system involvement, when infected with the measles virus. The national measles vaccination program, launched in 1963, has reduced measles incidence to fewer than 0.5 cases per 1,000,000 people in the U.S., eliminating its endemic status. However, outbreaks still occur due to exposure of nonimmune individuals or waning immunity from infected travelers. The presence of IgM-class antibodies suggests recent infection but should not be used alone to diagnose measles infection. The CDC recommends to obtain both a serum sample (for IgM antibody) and a throat swab or nasopharyngeal swab (for PCR) from patients suspected to have measles at first contact with them. Urine samples may also contain virus. When feasible to do so, collecting both respiratory and urine samples for PCR can increase the likelihood of detecting measles virus.

The absence of IgM-class antibodies suggests lack of an acute phase infection with measles virus. However, serology may be negative for IgM-class antibodies in early disease, and results should be interpreted in the context of clinical findings.

Testing for IgM-class antibodies to measles should be limited to patients with clinically compatible disease.

Immunofluorescence