PHAs across the country conduct thousands of case and outbreak investigations (Holst et al., 2025) and conduct surveillance on numerous conditions each year by monitoring hundreds of surveillance systems. These activities help PHAs to determine the extent and cause of illnesses, identify sources of poisonings, and describe circumstances around injuries to identify public health actions and preventive measures.  

These investigations involve confidentially collecting health information from tens of thousands of individuals.This information may include data obtained from patient interviews, medical records, laboratory reports, treatment plans, immunization records, etc. Healthcare organizations (HCOs) and laboratories are required to report conditions of public health importance to PHAs.​ Historically, this has been accomplished through manual reporting, such as phone calls, faxes, and mail; more recently, reports are also obtained via electronic formats which support timely detection and taking public health action in response to potential public health threats. These reports are crucial for effective public health disease monitoring (surveillance) and response (public health action), and many of them require follow-up activities that necessitate additional health information about the individuals who are affected. 

Access to EHI, which refers to an individuals’ health data that are collected, maintained, and stored electronically by healthcare providers (HCPs) or systems provides an opportunity for PHAs to achieve efficiencies. EHI access allows PHAs to obtain more complete and timely health information for public health surveillance and investigation. Having direct access to EHI can save time and resources for both PHAs and healthcare providers (HCPs) and reduce delays in taking appropriate public health action.