Establish evidence of early/acute infection with Bordetella pertussis, the causative agent of whooping cough.

Patients with acute infection develop IgG, IgM, and IgA antibodies to fimbrial agglutinogens, and IgM and IgA antibodies are probably diagnostic. Following vaccination, IgG and IgM antibodies can be demonstrated. The presence of specific IgM in a single sample may indicate an acute infection and should be considered suggestive of recent infection or a presumptive diagnosis of a supporting clinical presentation.