Tracking food-borne disease is also complicated by the number of illnesses thought to be caused by unknown pathogens.

ECONOMIST: Food poisoning

The genetics of common disease has just turned out to be much more complicated than we hoped.

FORBES: Gene Tests That Predict When You Will Die

One problem is that it is amazingly easy to get false positive results when scanning through complicated data sets and searching in the dark for correlations between genes and disease.

FORBES: Why You Shouldn't Trust Newfangled Gene Tests