The virus originated on an ice planet in an unnamed galaxy several billion light years from the Milky Way. Destiny, low on water reserves, stopped at this planet long enough for Colonel Everett Young and Lt. Matthew Scott to collect seemingly clean ice to replenish their supply. (SGU: "Water")
Unfortunately, the water collected from "Hoth" was not clean. Lt. Tamara Johansen discovered that the microscopes originally used to inspect the water were not powerful enough to detect the virus. Several - if not all - members of the expedition drank the water and began to feel sick. When they appear, the symptoms in the first three hours are nausea and muscle stiffness, followed by loss of consciousness. If untreated, the sickness is fatal. (SGU: "Time")
On a Jungle planet is a cure for the virus. However, the cure is in the venom of an extremely dangerous Squiggler. Because of solar flares interrupting the wormhole between the planet and Destiny, the expedition found a Kino on the planet that had been thrown back in time. After watching the Kino recordings of the experiences of the alternate timeline expedition members, they were able to determine that Lt. Matthew Scott was cured of the illness when bitten, but not killed, by one of the Squigglers; he awoke from a coma without any symptoms of the sickness.
With limited time before the solar flares would again interrupt the wormhole, the expedition decided to return to the planet and retrieve a live Squiggler. Unfortunately, it was already night and while on the planet, people had already begun to die on Destiny. Several creatures attacked and killed the members of the away team, except for Scott who sprinted back to the Stargate and dialed Destiny. He then left a Kino recording detailing all they had learned from the first Kino found on the planet and from T.J.'s studies of the virus. He waited for the solar flares to occur and then threw the Kino through the Stargate. (SGU: "Time")
In a third, and henceforth current timeline, the Destiny expedition found Scott's second Kino and traveled to the Jungle planet in daylight, captured a Squiggler, and cured the disease. (Kino: "New Kind of Crazy")