Ten PHEs completed the electronic survey and individual interview; the eleventh position was vacant at the time of the study (response rate = 100%). The 10 PHEs surveyed had been in their positions for an average of 49 months at the time of the study (range, 17-80 months). All PHEs held a minimum of a BA or BS degree; fields of study included biology (3), nursing (3), medical technology (2), sociology (1), and environmental health science (1). Eight PHEs held one or more master's degrees; fields of study included public health (3), microbiology (2), education (2), health care administration (1), and nursing (1). One PHE held a PhD in epidemiology. PHEs also reported training in infection control, communicable disease, incident command systems, forensic epidemiology, and risk communication. Nine PHEs were based in their hospital's infection control department, while the tenth was based in their medical center's infectious diseases section.
Of the 144 communicable disease and TB control nurses surveyed, 119 completed the electronic survey (response rate = 82.6%). These 119 nurses represented 74 (87.1%) of the state's 85 LHDs. Respondents indicated they had been in their current positions for an average of 7 years (range, 2 months-42 years). Of the 119 nurses that completed the survey, 88 (73.9%) had interacted with one or more PHEs on a professional basis in the past year (August 2009-July 2010).
Four NCDPH key informants were interviewed (2 program managers and 2 epidemiologists). All 11 hospital supervisors were interviewed (response rate = 100%). Hospital supervisors held positions as the director, assistant director, or manager of infection control (8), infectious disease physician (1), hospital epidemiologist (1), and chief medical officer (1).
Services provided by public health epidemiologists
PHEs estimated the time spent on each of their 5 areas of responsibility and listed the activities associated with each. Surveys and/or interviews with LHD-based nurses, NCDPH key informants, and PHEs' hospital supervisors confirmed these activities.
PHEs spend the largest percentage of their time (mean, 46%; range, 30%-50%) on activities related to surveillance. PHEs use North Carolina's statewide syndromic surveillance system-the North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT)-to monitor emergency department visits for their hospital system and investigate "signals" (i.e., increases in syndromes above pre-established thresholds [6
]). All PHEs have received training on the use of NCDETECT. In addition, PHEs actively monitor their hospital's admissions, lab, and death reports on a daily basis. When a case/cluster of interest is detected, PHEs access patient medical records to investigate if it represents a real event.
NCDPH utilizes the network of PHEs to support specific state surveillance objectives. At the time of the study, PHEs were conducting febrile respiratory illness admission surveillance and laboratory surveillance for viral respiratory pathogens. In addition, PHEs prioritize surveillance for specific diseases based on information received from NCDPH or LHDs about cases/clusters of communicable disease in the community or state.
PHEs spend the second largest percentage of their time assisting LHDs with communicable disease reporting and investigation (mean, 20%; range 10%-40%). PHEs report communicable disease cases to LHDs either directly or by assisting physicians, respond to LHD requests (e.g., for information from patients' medical records), facilitate access to physicians, alert LHDs of unusual cases/clusters among inpatients or emergency department outpatients, and perform descriptive epidemiology on clusters.
In addition, PHEs send weekly reports to LHDs on communicable disease cases at their hospital and disseminate similar weekly influenza reports during flu season. PHEs may also meet with nearby LHDs' "epidemiology teams" (multidisciplinary public health response teams) to review cases of epidemiological significance.
An average of 13% of PHEs' time is spent enhancing communication (range, 5%-30%). In most instances, activities listed under "assisting LHDs" and "educating clinicians" serve the dual purpose of enhancing communication. Moreover, PHEs enhance communication by providing NCDPH with nearly all of the same services they provide to LHDs (i.e., reporting cases and assisting with investigations). PHEs also provide NCDPH with a channel for disseminating information (e.g., CDC advisories, state guidance) to hospitals. PHEs further enhance communication by serving on hospital disaster preparedness committees, representing public health views and concerns.
PHEs spend an average of 9% of their time educating clinicians (range, 5%-20%) by providing annual or as needed training to medical students, residents, and clinicians on communicable disease reporting and infection control. PHEs also deliver in-service presentations to hospital clinicians regarding diseases of public health significance.
Conducting special studies accounts for an average of 9% of PHEs' time (range, 2%-15%). Examples of special studies include a PHE-led study of diagnosis codes for surveillance, participation in CDC/national studies, and hospital-initiated studies (e.g., outbreak of norovirus infection among bone transplant patients).
Value of the public health epidemiologist program
Interviews and surveys provided an opportunity for respondents from LHDs, NCDPH, and hospitals to rate and/or discuss the perceived value of the PHE program. LHD-based nurses who responded to the electronic survey rated the importance of 10 services received from PHEs (see Table ). All ten services were rated as very or somewhat important by over 87% of respondents. Respondents reported that information requested for public health investigations was received more quickly from PHEs than from staff at "non-PHE" hospitals (i.e., all other hospitals in the state except the 11 that house PHEs). Nearly 40% (39.8%) of respondents reported receiving requested information immediately from PHEs, while only 15.7% received requested information immediately from infection control practitioners (ICPs) or medical records staff at non-PHE hospitals.
Importance of Services Provided by Public Health Epidemiologists to Local Health Departments
To further gauge LHDs' perception of the value of the PHE program, nurses rated the impact of the PHE program on four measures. Of the respondents that interacted with a PHE in the past year, 85% or more reported that the PHE program either greatly or somewhat enhanced 1) communication between hospitals and LHDs, 2) the timeliness of communicable disease reporting, 3) the completeness of communicable disease reporting, and 4) their LHD's efficiency in reporting and investigating communicable disease in the community.
NCDPH key informants placed a high value on the PHE program's ability to enhance the timeliness of case reporting and response, sensitivity/specificity of syndromic surveillance, and communication with hospitals. One key informant reported that the PHE program has increased the flow of information around communicable disease reporting and investigation, allowing for timelier interventions. PHEs immediately report significant cases to NCDPH, and can quickly access and share needed information from patient medical records, thereby increasing the speed of response. A second key informant highlighted the value of PHE program in enhancing surveillance, noting that surveillance information gathered by PHEs has been more specific than data available through the NC syndromic surveillance system. "Having a human being looking at cases and excluding the ones that have been clearly attributed to a non-flu cause is helpful and that is something we cannot do with [the syndromic surveillance system]." Key informants also emphasized the value of PHEs in connecting NCDPH to hospitals. PHEs provide "on the ground access to the issue of the day... and [act as] our liaison for dealing with the situation."
In discussing the value of the program to hospitals, PHEs' supervisors highlighted two unique aspects of the PHE role-its focus on syndromic surveillance of community-acquired infections and bioterrorism events, and its connection to public health agencies. Supervisors noted that this role is distinct from that of ICPs, who focus on hospital-acquired infections.
Eight supervisors noted that PHEs had played a significant role in responding to a public health emergency or outbreak (other than H1N1), including an E. coli outbreak at the state fair, illness related to contaminated street drugs, and various localized outbreaks of norovirus infection, pertussis, shigellosis, and cryptosporidiosis. Supervisors reported that PHEs often identified the outbreak and took an active role in responding by sharing key information (e.g., case definition, exposures) with frontline responders (e.g., emergency department and clinic staff). Using a scale of 1 to 10, supervisors rated the role played by their PHE in responding to public health emergencies or outbreaks (other than H1N1) as highly valuable (mean, 9.6; range, 8-10).
Supervisors also emphasized the value of the PHE position in providing a bridge between their hospital and public health agencies. Supervisors noted that PHEs' connection to public health resources allows hospitals to stay abreast of national trends, guidelines, and best practices regarding the management of diseases of public health significance. In addition, PHEs help "hospital staff to have a better comprehension of the role of public health and how we need to partner to promote the wellness and health of the community as a whole." Sub- heading for this section
Role of public health epidemiologists in the 2009 H1N1 pandemic response
The specific activities carried out by PHEs during the H1N1 pandemic are listed in Table . Approximately half of all LHD-based nurses surveyed interacted with a PHE. Over 85% of these respondents reported that that PHEs either greatly or somewhat enhanced communication between hospitals and LHDs with regard to H1N1 reporting and investigation, the timeliness and completeness of H1N1 reporting, and their LHD's efficiency in reporting and investigating H1N1 in the community (see Table ).
Public Health Epidemiologists' Role in the 2009 H1N1 Pandemic Response
Impact of Public Health Epidemiologists on Local Health Department Reporting and Investigation of H1N1
In discussing the value of PHEs in responding to H1N1, NCDPH key informants emphasized PHEs' ability to provide timely surveillance data to NCDPH and facilitate communication with hospitals. One NCDPH key informant noted, "They were really our link to those hospitals...[without the PHEs] we wouldn't have had a good sense of how many cases they're seeing, how many cases are in ICU [intensive care unit], how many cases among pregnant women and kids... it guided our recommendations on surveillance, testing, and infection control." A second key informant reported that PHEs "were integral in communicating case definitions and guidance information on treatment, isolation, and quarantine to their hospitals." NCDPH informants also valued PHEs' flexibility in quickly adapting the focus of their surveillance efforts to meet changing needs and priorities during the pandemic. "It didn't take time at all for them if requirements were changed. For example, monitor acute respiratory admissions, then monitor death, then monitor pregnant women with influenza, or monitor ICU admissions."
PHEs' hospital supervisors placed a high value on the role played by their PHE in responding to the pandemic, giving them an average score of 9.1 (range, 5-10) on a scale of 1 to 10. Hospital supervisors reported that PHEs were instrumental in helping develop hospital policies/protocols for the management of H1N1 based on surveillance data and state and federal guidance, and educating hospital staff on these policies/protocols. Having a PHE "allowed us to be linked with other PHEs and other resources in the state...[and] with the federal folks so that we could ensure that we were aware of what was going on and our response to what was going on in the region was the most appropriate thing to do at the time."