Flu by Simmons and Infection by Schubert have the exact same cover.  Infection doesnt show a cover here, but both are on Amazon with the same one.

It's a piece of stock photography that they bought for their covers from the artist or a company that supplies cover artwork.  Unfortunately they both bought the same one.  I saw a few months ago that there was the same cover used for some larger, more mainstream authors, with the main difference one was tinted blue, the other red, but I can't recall the title at the moment.  If you google you can find other examples, (and a link to this post: http://www.paperbackswap.com/Two-Books-Same-Cover/topic/167593/?&l=25&ls=0)