The U.S. Department of Homeland Security is still unable to determine if a key program to detect bio-threats actually works, auditors say. (AP Photo/Eric Gay)

More than a decade after the Department of Homeland Security began a program to fight biological terrorism, “considerable uncertainty” remains over whether the system can reliably detect biological threats, a new federal audit says.

The report by the U.S. Government Accountability Office is the latest blow to DHS’s BioWatch system, the agency’s marquee post-Sept. 11, 2001, effort to detect pathogens that could signal a devastating biological attack. After scientific studies and media reports raised concern about BioWatch’s effectiveness, DHS last year canceled the system’s planned next generation of sensors.

{Homeland Security cancels plans for new BioWatch technology}

Now, GAO says the government still lacks reliable information about the current generation, first deployed in 2005, to determine if it is capable of detecting a biological attack. DHS’s testing of the current system — known as Generation-2, or Gen-2 — has been flawed, leaving the department unable to properly determine how to improve it, GAO found.

“DHS lacks reliable information about BioWatch Gen-2’s technical capabilities to detect a biological attack and therefore lacks the basis for informed cost-benefit decisions about possible upgrades or enhancements to the system,” the report said. “The nation’s ability to detect threats against its security requires judicious use of resources directed toward systems whose capabilities can be demonstrated.”

DHS officials defended BioWatch program, which consists of aerosol collectors deployed in more than 30 cities nationwide that draw in air through filters. The filters are collected and taken to laboratories for analysis to check for the presence of anthrax and other pathogens. The system was first deployed in 2003, in response to Sept. 11 and the anthrax attacks that followed.““““““““““““““““““““““““““`

{Costly weapon detection plans are in disarray, investigators say}

“The Department of Homeland Security’s BioWatch program is the only federally-managed, locally-operated nationwide bio-surveillance system designed to detect select aerosolized biological agents and remains a critical part of our nation’s defense against biological threats,” said S.Y. Lee, a DHS spokesman. While the department “does not agree with all of GAO’s characterizations of our BioWatch efforts,” Lee said, it concurred with all of the recommendations in the report.

Those recommendations included not allowing DHS to pursue upgrades or enhancements to BioWatch until it establishes “technical performance requirements” to better determine how well the current system works.

The report illustrates the difficulties the government has faced since Sept. 11 in developing a reliable and easy way to detect deadly pathogens, even though the bio-defense research industry has spent billions of dollars on the effort.

{Audit slams DHS for canceling technology to fight bio-threats}

A 2011 report by the Institute of Medicine and the National Research Council concluded that BioWatch faced “serious technical and operational challenges” and had been rushed into deployment before it was properly tested.

The new GAO report also found fault with DHS’s testing procedures, saying that even as the agency commissioned several tests of the current Generation-2 of BioWatch, it had “not developed performance requirements that would enable it to interpret the test results and draw conclusions about the system’s ability to detect attacks.”

DHS disputed that in a response contained within the report, saying that evaluations are done “to provide confidence in the precision and reliability of the system’s capabilities.”