If anyone is still interested, the best sci fi horror that I have recently read is the Infected series by Scott Sigler.
I am on a copy/paste deficient device, so here's the summary of book one (there are three and I highly recommend them all).
"The book follows several characters as they deal with an alien invasion on the microscopic level. The narration is primarily through the perspectives of Perry Dawsey, an ex-football player with an anger problem, and Margaret Montoya, an epidemiologist with the CDC who is investigating a strange disease that turns seemingly normal people into murderers."
It's very good, I'd love to know if anyone has read them.