slow virus

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of a group of viruses that cause various diseases with a long latent period and a slow, progressive course, such as subacute sclerosing panencephalitis.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a virus that remains dormant in the body for a long time before symptoms appear