During the past decade, significant federal investments were made to improve the nation’s response to bioterrorism, pandemic influenza, and other emerging threats. Those investments supported the development and acquisition of medical countermeasures, such as vaccines, and also strengthened diagnostics capability – that is, the ability for laboratories to detect threat agents. Medical countermeasures and diagnostics capability are currently at a critical intersection – without accurate and rapid diagnostics, it is difficult to determine the appropriate course of treatment or other countermeasure. Although most people may be familiar with vaccines, antibiotics, and antivirals, many are unaware of the behind-the-scenes work of laboratories to detect the causative threat agent.
Identifying, Testing & Characterizing Samples Formed in 1999 by the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and the Federal Bureau of Investigation (FBI), the Laboratory Response Network (LRN) is the nation’s premier system for rapidlyentifying, testing, and characterizing potential agents of biological and chemical terrorism and other emerging public health threats. The LRN maintains an integrated national and international network of laboratories that can respond quickly to acts of chemical or biological terrorism, emerging infectious diseases, and other public health threats. State and local public health laboratories comprise approximately 70 percent of the LRN Biological Reference Laboratories and almost 100 percent of the LRN Chemical Laboratories. These laboratories produce high-confidence test results that form the basis for threat analysis and intervention by both public health and law enforcement authorities.
The LRN for Biological Threat Preparedness is organized as a three-tiered pyramid. At the foundation are thousands of sentinel clinical laboratories, which perform initial screening of potential pathogens. When sentinel clinical laboratories cannot rule out the presence of a biological threat agent, they refer specimens and isolates to the appropriate LRN reference laboratory. More than 160 local, state, and federal facilities provide rapid reference testing. At the apex are national laboratories, such as those at the CDC and the Department of Defense. These laboratories test and characterize samples that pose challenges beyond the capabilities of reference laboratories, and provide support for other LRN members during a serious outbreak, public health emergency, or terrorist event. The most dangerous or perplexing pathogens are handled only at the highest level biosafety laboratories (BSL-4) at CDC and the U.S. Army Medical Research Institute of Infectious Diseases.
Diagnostics as a Countermeasure Tool Following the release of a biological threat agent, clinical diagnostic assays are important tools to distinguish infected, exposed, and “worried-well” populations. The detection of exposures will determine which people need treatment (infected) and which require post-exposure prophylaxis (exposed, but asymptomatic). LRN reference laboratories are conducting ongoing public health surveillance testing on clinical specimens and non-clinical samples, such as food, surface swabs, air filters, and white powders, for a myriad of biological threat agents. These laboratories serve a vital function in all phases of a terrorist or other public health threat: (a) pre-event (surveillance testing); (b) event (rapid diagnostics, connection to sentinel clinical laboratories, local law enforcement/first responders, and FBI for rapid response); and (c) post-event (remediation/clean-up).
In addition to their role in the LRN, state and local public health laboratories play a vital role in protecting the nation’s health – whether detecting the next resistant strain of tuberculosis orentifying a novel pathogen such as Influenza A H1N1. These laboratories are at the forefront of the diagnostics that provide guidelines for the use of medical countermeasures such as antibiotics, antivirals, or other non-pharmaceutical intervention – appropriate personal protective equipment, for example.
In the future, it will be important to see a continued commitment from governmental leaders to improve the development of robust rapid assays for the detection of public health threats in clinical samples such as human blood and non-clinical samples such as powders or water. Rapid diagnostics are critical for providing the information necessary to deploy and distribute medical countermeasures.
________________________ Chris N. Mangal, MPH, is the director of public health preparedness and response at the Association of Public Health Laboratories (APHL). The recipient of a bachelor’s degree in microbiology from the University of Florida, and of a master of public health degree from the University of South Florida, she is responsible for providing programmatic and scientific leadership for preparedness activities for the benefit of APHL members, staff, and partner organizations, such as the Centers for Disease Control and Prevention (CDC). Chris has over ten years of experience working to improve laboratory practice in the detection of public health threats, and to expand and enhance the relationships between APHL member laboratories and CDC, other federal agencies, and private organizations involved in emergency preparedness and response, public health testing, policy, and training.