Interpretation

The presence of IgM-class antibodies, with or without the presence of IgG-class antibodies, to measles virus may support a clinical diagnosis of recent/acute phase infection with the virus. IgM results alone should not be used to diagnose measles virus infection.

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.

The presence of detectable IgG-class antibodies, in the absence of IgM-class antibodies, indicates prior exposure to the measles virus through infection or immunization. These individuals are considered immune to measles infection.

The absence of detectable IgG-class antibodies suggests the lack of a specific immune response to immunization or no prior exposure to the measles virus. These individuals are considered nonimmune to measles virus infection.