As with data about West-Nile and rabies, Lyme Disease stats are collected on a county level. Physicians in NY State are required to submit positive test results to county health departments. The county health commissioners then report findings to Albany.

For what it?s worth? the state health dept. website has a table of Lyme numbers by county, expressed both in absolute number of cases, and as a rate, termed as cases per a 100,000 population unit. (The data lags a few years, as you would expect from a government agency). So, in 2005, Orange County shows 136 cases per 100,000 (if I?m reading this table correctly). By this rate, using the official village population (as per the 2000 census) of 3,058, the interpolated number here would have been an implied 4.16 cases of Lyme Disease in Cornwall-on-Hudson in 2005. In the Town of Cornwall (using a census based population of 12,307), the implied number of cases would have been 16.74 for the same year. Adding them together for ?Greater Cornwall? the number is about 21.

You can view this table at:
http://www.health.state.ny.us/statistics/chac/general/lyme.htm