In January 2003, the Westchester County Departments of Information Technology (DoIT) and Health (WCDH) jointly launched its highly sophisticated computerized early warning surveillance system. 

Today, 100 per cent of hospitals with emergency departments and selected outpatient clinics electronically send data files. An integral part of the county’s efforts to improve emergency preparedness, the Community Health Electronic Surveillance System (CHESS) is used daily to track and statistically analyze unusual levels or patterns of disease using SPSS statistical software. Findings are communicated to clinical staff each morning for review and possible follow-up. 

In these critical times, CHESS exemplifies the partnership of public health and technology in combating bioterrorism and other harmful outbreaks of illness.