It is used for Determining acute-phase infection with rubeola (measles) virus using IgM antibody testing. Aiding in the identification of nonimmune individuals through IgM antibody testing. The measles virus is among the most highly contagious infectious diseases among unvaccinated individuals and is transmitted through direct contact with aerosolized droplets or other respiratory secretions from infected individuals. 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.