Waiting to exhale: The recent detection of tularemia bacteria on Washington’s National Mall on the weekend of the big anti-war rally to protest the war in Iraq brought to light the BioWatch program. Most of us probably forgot that George Bush announced the implementation of the BioWatch program during his 2003 State of the Union address.
The program falls under the general auspices of the Department of Homeland Security, and also involves the Centers for Disease Control and Prevention, the FBI and the National Security Agency. It is shrouded in secrecy.
The function of the BioWatch Program is to detect the release of pathogens into the air, providing warning to the government and public health community of a potential bioterror event. While there is limited federal government description of the BioWatch Program, there have been media reports describing the functional concept. According to these reports, aerosol samplers mounted on pre-existing Environmental Protection Agency air quality monitoring stations collect air, passing it through filters. These filters are manually collected at regular, reportedly 24-hour, intervals and are analyzed for potential biological weapon pathogens using polymerase chain reaction techniques.
While filters from the BioWatch program were initially shipped to and tested at a federal laboratory in California, state and local public health laboratories now perform the analyses. News reports suggest that the system tests for pathogens that cause anthrax, smallpox, plague and tularemia (a bacterial illness, sometimes called “rabbit fever”), but the entire list of pathogens is not publicly available.
BioWatch equipment is fielded in select cities, reportedly including Philadelphia, New York, Washington, San Diego, Boston, Chicago, San Francisco, St. Louis, Houston and Los Angeles. The Department of Homeland Security has not confirmed the exact number of cities engaged in the BioWatch program, nor the number of pathogens that are detected using BioWatch equipment. It is reported that at least 31 cities are included in the program, while according to the minutes of a Centers for Disease Control and Prevention Information Council meeting, the program may expand to as many as 120 cities. While the exact cost of this program is unknown, the capital costs for installation in a single city are estimated at $1 million and the yearly budget for operation at $1 million per city.
The press has reported that state and local public health labs conducting BioWatch testing are all part of the national Laboratory Response Network for Bioterrorism (LRN). The LRN is a nationwide network composed primarily of local, state and federal government laboratories. It was developed by the CDC, the Federal Bureau of Investigation, and the Association of Public Health Laboratories prior to the anthrax mailings of 2001. It provides confirmatory testing in all 50 state public health labs and in additional locations. There are currently 118 member labs in the LRN.
BioWatch equipment is heavily based on the Biological Aerosol Sentry and Information System (BASIS), a system developed within the Chemical and Biological National Security Program of the National Nuclear Security Administration (now part of the Department of Homeland Security) by scientists at Lawrence Livermore and Los Alamos National Laboratories. BASIS is composed of an air collector coupled to a series of filters. Airborne particles passing through the system are captured on a filter. The filter mechanism is designed to roughly determine when an attack occurred by using sequential filters automatically rotated on an hourly basis. Filters are removed and tested using PCR for the presence of select pathogens.
BASIS was deployed for both indoor and outdoor monitoring at the Salt Lake City Olympics in 2002, and was also tested and characterized in urban settings. Some conclusions about instrument performance based on these tests were released. BASIS was characterized as having high specificity, with fewer than 0.005% false positives per filter measurement, and high sensitivity. However, BASIS was noted to be labor intensive, requiring people to collect filters and perform PCR testing and analysis.
The first incident of a positive BioWatch result was reported on October 9, 2003, in Houston, Texas. The Houston Department of Health and Human Services reported detecting low levels of the bacterium that causes tularemia. According to a press release, positive results were detected on three consecutive days, with negative results on subsequent days.
The response to the positive result was a modest one with precautionary measures being taken by the local and state public health agencies, including increased surveillance for human illness; additional environmental sampling and testing; and assessment of activities in the area that may have caused the sensors to pick up the organism. There are no indications that this signal was the result of an intentional pathogen release, but investigation is ongoing with federal, state and local agency participation.
The Director of the Houston Department of Health and Human Services stated, “We are investigating to determine if the bacteria was always present or newly present and if it represents a health threat to the community.” These findings may likely reflect natural “background” levels of the organism in the environment, and authorities have chosen to enhance surveillance rather than distribute antibiotics in the affected community.
While the system might appear to function well, there does seem to be a disconnect between detection and action — something that has become a hallmark of the Department of Homeland Security and its divisions, including the Federal Emergency Management Agency.
