Mallein Test

The mallein test is a sensitive and specific clinical test used to diagnose glanders, a bacterial disease of horses, donkeys and mules caused by Burkholderia mallei, a pathogen that is also contagious to humans and other species. Structured as a type 4 delayed hypersensitivity test, it involves injecting mallein, a protein fraction of the bacterium, usually as an eye drop; in an infected animal this produces swelling around the eye within about 48 hours, sometimes with discharge and conjunctivitis, while the test itself is non-toxic to healthy animals. Because glanders is a reportable disease, its occurrence must be reported to the World Organisation for Animal Health.