Public Health Surveillance System Update

Indiana Epidemiology Newsletter
October 2006

Michael Wade, MPH, MS
Syndromic Surveillance Epidemiologist

The purpose of the Indiana Public Health Emergency Surveillance System (PHESS) is to detect acts of bioterrorism, disease outbreaks, and other public health emergencies as early as possible. In addition, the PHESS augments traditional disease surveillance by offering a “situational awareness” capability during known outbreaks. The purpose of this article is to describe the continued evolution of Indiana’s PHESS.

Over the past year, we have enhanced the Indiana PHESS by connecting 29 additional hospital emergency departments (ED) to the system. The PHESS now includes 67 EDs securely transmitting patient chief complaint data to the ISDH in near real-time. (We anticipate connecting 12 additional hospitals by August 2007.) These additional ED data sources have nearly doubled the daily surveillance data flow through the ESSENCE data analysis tool, from 3,500 patient encounters in August 2005 to 6,000 currently. Further, these hospital connections provide enhanced geographic coverage, thereby improving the performance capability of the PHESS. While expanding the PHESS by simply adding more ED data sources is necessary to achieve adequate coverage, another way to improve the system is to increase the number of appropriate public health officials who view these data. With additional users viewing data through ESSENCE, analysis and response time are enhanced.

Early in 2006, the ISDH PHESS staff partnered with a group of Indiana public health professionals participating in a leadership development program through the Mid-America Regional Public Health Training Institute (MARPHLI). As their final project, group members volunteered to develop training materials to pilot with counties and hospitals participating in the PHESS. This pilot was conducted in Marion, Montgomery, Delaware, Monroe, Vigo, Vanderburgh, and Warrick Counties. Local health department (LHD) and hospital personnel were given a general orientation to the PHESS and educated specifically on the use of the ESSENCE data analysis tool. User accounts were created for the appropriate individuals at each organization so they could access the data for their LHDs or hospital(s). The ESSENCE pilot project was time well spent in developing important relationships, enhancing capacity at the local level, and improving the ISDH’s approach to the future statewide rollout of ESSENCE. Expanding access to the PHESS syndromic surveillance data in this way greatly improves the ability to identify, and if needed, respond to significant public health events.

During the early development phase of the PHESS, access to syndromic surveillance data was necessarily limited to the Indiana State Department of Health (ISDH) PHESS staff and a small group of individuals at the Marion County Health Department. This time was used to establish a reliable syndromic data flow and for epidemiology staff to learn how to “read” the data. While the ESSENCE interface does an outstanding job of categorizing and statistically processing the data, a skilled epidemiologist must ultimately discern what data truly appear to have both statistical significance, as well as practical public health significance. When PHESS epidemiologists think alert data merit further investigation, these data are relayed to an ISDH field epidemiologist for follow-up with the hospital and LHD. As LHDs and hospitals gain access to ESSENCE, the field epidemiologists will be able to send secure data links to them via email, vastly improving the investigation process.

Currently, the ISDH PHESS staff are gearing up to provide ESSENCE access and training for key infection control and ED personnel at all Indiana hospitals connected to the PHESS and all LHDs. This rollout is expected to be completed by early 2007.