I really enjoyed this story, which is saying something as this type of novel (crime/thriller) usually doesn't appeal to me. That said, I had one major gripe, which is why Patient Zero gets 3 stars instead of 4, and that is the main character. 
 Joe Ledger is a little hard to swallow. Not because he is seemingly perfect in every way (although that IS a bit of a turn off from a story for me), but because he seems to go to try so hard to be self-deprecating, and all the other characters seem happy to continually reassure him that he isn't as bad as he thinks. 
 That's one gripe, however. I liked the concept and the execution of the overall story, and I would recommend this to any fan of zombie, thriller or crime novels.