French Cheese

Rage stops what appears to be a drunk driver on the way to work. He dies the next day in the hospital. The gave him 26 points of blood but could not stop the blood from clotting in his veins. The hospital notifies the CDC of the unusual case. The CDC has no idea the cause.
In Seattle, the case is given to Inspector Strong to review. The CDC instructions are to wraps the body and car with special plastic. The CDC sends an agent to determine the cause. All federal agencies are notified of this death.
The CDC fears a plague. They take blood samples from everyone that even came close to the person. Then they find he spent two weeks in Europe and has a new job at a dairy. It is panic time for the CDC. She threatens to close the airport, the dairy, and everyplace he has been. They are unable to identify or recreate the blood clotting.
They first assumed it was terrorists, then murder, then an accident he caused, the cheese he bought in Europe, the cheese caves he visited.
Each investigation is a dead end. The CDC buys his apartment, then the entire floor. It is remodeled, cleaned with live steam. His body, car, apartment is all wrapped and burned or placed in a blast furnace.