CDC’s Biosense program uses statistics from a variety of sources to develop benchmarks to detect emerging health crises.
For an example of how it is used see Haobo Ma, Jerome I. Tokars, Roseanne English, Theresa L. Smith, Colleen Bradley, Leslie Sokolow, Henry Rolka. Surveillance of West Nile Virus Activity Using Biosense Laboratory Test Order Data. Advances in Disease Surveillance, Vol 1 (2006) available online here.