Effect: Your total number of healing surges is reduced by 1 while under the effects of the disease. You suffer a -2 to fort defense.
Cure: Each day you make a saving throw. You must have 3 successful saving throws to recover from the disease. A DC 15 heal check can provide a +1 to a saving throw.
(a common cold remedy should be cheap and easy to come by, a rare disease needs a rare component, so you can start an adventure with it - Does anyone know Elenium saga of Eddings?)
I will be happy enough if 4e diseases do not expire at the end of the encounter
By the way, 3e disease rules were excellent. They should have used the same rules for poisons (modified to work by the hours eventually), because instead 3e poison rules sucked.