While a federal program for detecting a biological weapons attack has operational weaknesses, the effort should not be discontinued, public health specialists said in a Friday Center for Infectious Disease Research and Policy report.
A recent Los Angeles Times report enumerated a number of technical shortcomings of the Biowatch program, which deploys sensors that scan the environment for disease agents in more than 30 cities. Biowatch detectors from 2003 through 2009 raised in excess of 50 false alerts of a potential bioterrorism attack. Computer exercises have also determined that the sensors are not reliable, among other challenges.
"From a local perspective, the information and issues raised in the article are not new to us," said National Association of County and City Health Officials public health preparedness head Jack Herrman. "These are things we've heard consistently over the years from local health departments."
"However, I think it's important that we don't kind of bash the system in the absence of any other technology that's better," Herrman continued. "More important, I think we should focus on what we need to develop in human and technological resources that can provide us with timely and accurate data that can detect the presence of potentially life-threatening pathogens."
Milwaukee Health Department disease control chief Paul Biedrzycki noted that Biowatch as a novel system had its deficiencies. "I can understand why (some public health officials) don't think it's useful because of the sensitivity and specificity limitations. But it does add to the common operating picture. It is the only biosurveillance program I'm aware of that has some dimension of standardization in terms of collection and analysis of data in the country."
Homeland Security Department officials insist that Biowatch does not issue needless alarms. They argue that a number of the pathogens the technology is intended to detect such as anthrax are naturally occurring, which can make it difficult for laboratory scientists to determine if the disease agent's presence is an act of nature or an intentional act. Seven million analyses have on 37 occasions turned up environmental disease material, according to DHS chief medical officer Alexander Garza.
Department officials claimed the program has been praised by state and city officials for its involvement of emergency responders, health professionals and other government personnel.
Biedrzycki said the confined scope of the Biowatch program means that biological weapon attacks in uncovered areas might not be identified. Other factors such as the kind of pathogen, its lifespan, the day's climate, and the sensor's location could impact detection of biological weapons.
"Some events may be under the radar for those reasons, the number of variables and the complexity of interactions among them," the Milwaukee health official said. "On the other hand, there are some things that could be picked up, if there were sufficient concentration.
"I don't think the system by any account is useless," he added.
Even the alarms raised by the biosensors have resulted in positive changes to the system, Biedrzycki said. "All of the protocols have been enhanced as a result of what the [Times] article referred to as false alarms. They have stimulated discussion, identified gaps, and improved protocols that I think will be extremely helpful."