The pathogen of Andronesian encephalitis.
Andronesian encephalitis is an unpleasant, but not life-threatening, disease transmitted by airborne particles that is common in Federation space due to the transmission of the particles via space travel.
In 2154, a sample of this disease's pathogen was stored at Cold Station 12. (ENT: "Cold Station 12")
Although the disease was easily treated and regarded as a minor condition by 2365, Anya, the guardian of the Dauphin of Daled IV, regarded it as a threat and requested that the person infected be terminated. (TNG: "The Dauphin")