Ticks as small as a freckle can transmit a number of illnesses for which there is no vaccine and, in some cases, no cure. These creatures even could become bioterrorism weapons.

A New York Medical College microbiologist warns that live virus vaccines to prevent infectious diseases like West Nile virus and yellow fever could have dire consequences.

After a long hike through some of California's forests, it may be tempting to rest on a log or lean against a tree. Wrong move, say researchers at the University of California, Berkeley, who found that such activities may increase the risk of acquiring ticks harboring the Lyme disease bacterium.

A specific outer-surface protein found in the bacterium that causes tick-borne Lyme disease is essential to survival of the bacterium in its natural life cycle and colonization in the insect, researchers at UT Southwestern Medical Center at Dallas have found.