The epidemiology and surveillance workforce among local health departments in California: mutual aid and surge capacity for routine and emergency infectious disease situations.

Public health surveillance and epidemiologic investigations are critical functions for the control and prevention of infectious diseases. The activities associated with these functions, including case and contact investigations, public health surveillance, and data analysis, are conducted by trained personnel in response to a variety of infectious disease threats, including those with pandemic potential, such as novel influenza.1–3 According to the 2010 National Profile of Local Health Departments, 92% of local health departments (LHDs) in the United States conduct epidemiology and surveillance for communicable diseases, while 77% conduct these activities for environmental health issues.4 In 2005, approximately 25% of all LHDs employed one or more epidemiologists, and epidemiologic activities were conducted by individuals with a wide range of backgrounds and training.5 For many LHDs that do not employ epidemiologists, other public health professionals (e.g., health officers, public health nurses, or environmental health staff) may fulfill epidemiologic functions within the LHD. To create and maintain sustainable preparedness and response systems, the public health workforce must have the proper skills, capabilities, and adequate staffing levels to respond successfully in a public health emergency.6 In 2007, the results of a survey of LHDs in California demonstrated that not all disease investigation staff had received basic epidemiology training and not all staff that might supply surge capacity for disease investigations had received formal disease investigation training.7 In 2005, 12 of 56 (21%) LHDs reported having a formal agreement with neighboring jurisdictions to secure services of qualified epidemiologists in an emergency.8 From 2006 to 2010, cuts to bioterrorism and emergency response funding resulted in substantial decreases in epidemiology capacity among state health departments nationally.9 Despite the decrease in preparedness and response funding, public health preparedness and emergency response remains an area of critical importance for LHDs; maintaining the public health capacity to detect, investigate, and respond to infectious disease threats is an essential component of preparedness efforts.10 The purpose of this study was to describe the public health workforce involved in public health surveillance and epidemiologic activities among LHDs in California. Other studies such as the Council of State and Territorial Epidemiologists (CSTE) Epidemiology Capacity Assessments (ECAs)11–15 have attempted to enumerate and assess the epidemiology capacity among LHDs in the United States. Our goals were to describe the functional epidemiology capacity among California LHDs, understand the internal and external networks that are used to support epidemiologic and surveillance functions, and find out how health departments recruit additional epidemiologic support during infectious disease emergency events. For the purposes of this study, we have defined “functional epidemiology capacity” to mean the ability of the organization to conduct epidemiology-related tasks, regardless of the personnel performing them. An in-depth understanding of the sources of epidemiologic support during infectious disease emergencies and ensuring these individuals are trained to meet the functional needs are essential to an effective public health response.