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U.S Defends Tularemia Response By David Francis WASHINGTON — The U.S. Homeland Security Department is defending its response to the detection of tularemia last month on the National Mall in Washington, D.C., saying that delays in releasing information to local health authorities were caused by routine laboratory work to verify the pathogen’s presence (see GSN, Oct. 5). On Sept. 24, during a war protest and national book festival, low levels of tularemia were detected on the Mall. Homeland Security officials announced nearly a week later that the bacteria was naturally occurring and posed no health threat. Homeland Security first suspected a problem when six sensors used in the BioWatch biological agent surveillance system collected air samples that indicated tularemia might have been present on the Mall. However, those results were not considered entirely definitive under BioWatch standards, so Homeland Security did not inform local public health officials in Washington for several days to avoid a public panic, said Jeffrey Stiefel, the department’s BioWatch chief. Subsequent testing at the Centers for Disease Control and Prevention confirmed that there were low levels of tularemia on the Mall, Stiefel said. On Sept. 30, local health officials and the public were told to watch out for symptoms of the disease, which include chills, fever, headache, muscle aches and pneumonia. The $60 million BioWatch System has been established in more than 30 cities around the country. First installed following the 9/11 terrorist attacks, the equipment collects air samples, which federal laboratories test for biological agents every 24 hours. The National Mall tularemia incident was the third instance in which the system has detected the presence of a biological agent. Tests of previous BioWatch positives in San Diego and Houston showed that the pathogens detected occurred naturally, Stiefel said. Stiefel argued that spreading the word before the tularemia finding was confirmed could have created a false panic and undermined the credibility of the BioWatch program. Some biological weapons experts, however, have criticized Homeland Security for failing to inform the Centers for Disease Control and Prevention and local health agencies about the presence of tularemia until days after the pathogen was detected. Failure to receive this information would prevent health officials from identifying early signs of an outbreak, they said. “I don’t think the system worked very well,” said William Stanhope, associate special projects director at the St. Louis University School of Public Health's Institute for Biosecurity. “We had pretty good evidence something happened. There was a delay in getting that info from Washington to Atlanta [home of the Centers for Disease Control]. That delay should never have occurred. CDC should have been notified immediately.” Initial Test Raises Red FlagTularemia is commonly known as Rabbit Fever and is not spread from person to person. It can be contracted from animals or insects and can be aerosolized and used as a biological weapon. The disease is treatable, but can be fatal if ignored, according to the Centers for Disease Control. Air samples from the Mall did not have the adequate number of tularemia DNA markers to be considered a positive under the BioWatch system. Stiefel said the first round of tests on Sept. 25 at the Homeland Security laboratory indicated the presence of only a few tularemia genetic markers. That did not meet the BioWatch threshold for a positive match. Stiefel said this was the first time his agency has seen such results under BioWatch. Still, the unusual data led the director of the Washington laboratory to conduct additional tests on the samples on Sept. 27. “The laboratory director … looked over the results from the weekend, and saw the results of these tests, talked to the person who ran the tests, and decided that this person would rerun the tests,” Stiefel said. “When they did that, she got the same exact results. … So again, we don’t have a confirmed BioWatch positive, but we have something that looks very interesting because we hadn’t seen that kind of signal coming before.” On Sept. 28, Homeland Security contacted researchers at Lawrence Livermore National Laboratory in California to discuss the results. The Washington area laboratory then asked the Centers for Disease Control on Sept. 29 to review the findings. This was the first time the center heard of the incident, Stiefel said. After reviewing the data, CDC officials asked for samples to be sent for further review. The samples arrived on Sept. 30. The Centers for Disease Control the previous day had notified Washington region health agencies of the possibility of tularemia on the Mall, Stiefel said. The federal health agency reviewed the samples, confirmed the previous findings that day and quickly informed the Health and Human Services Department. It was then decided that a nationwide health notice would be issued, alerting the public to watch out for tularemia symptoms. “Based on that information, CDC issued a nationwide alert for people who could have been on the Mall during that time, to their public health officials, to say … if any people say that they were on the Washington, D.C., Mall during this time period come down with these kinds of symptoms,” be aware that tests confirmed the presence of tularemia, Stiefel said. The long delay between the collection of the samples that tested positive for tularemia was due to BioWatch protocols, Stiefel said. If the samples had tested positive for all tularemia indications, a warning would have been issued immediately. “What we don’t know is whether it was an emergency or not,” Stiefel said. “Keep in mind, if we had had a BioWatch-confirmed PCR positive [a test to confirm genetic makeup], the notification would have gone out late Sunday afternoon, and that would have alerted everybody and it would have followed the BioWatch protocols for the alert notification and all the local agencies that have to be notified.” “We did not have that in this case,” he continued. “Now what we did see … was very, very, very low” indications of the bacteria. Stiefel said the caution exhibited by federal health authorities is necessary to ensure that no false positives are declared, shaking the public confidence and causing panic. The system must remain absolutely trustworthy in order to stay relevant, he said. “Consider the fact that you’re in a city, or in a building, or in an airport and if you get this false positive signal you shut down this facility. If you’re in a train station or a Metro station and you decide to shut down the transit system because of a false positive, you’ve now got nobody coming in, nobody going out, and you’re concerned that the trains you have are contaminated,” Stiefel said. “There are a lot of implications for having a false positive. So the BioWatch system is set up so that we don’t get false positives.” “You energize a lot of different systems when that happens, and if it turns out that the signal is false, it’s got a huge monetary implication to it, it’s a big trust [issue] — as far as the people who respond to that signal and the public in general — it’s the ‘cry wolf” syndrome,” he added. “If you get something that’s a false positive, eventually it gets to the point where you don’t respond anymore.” Stiefel also dismissed the case made by Stanhope and other experts in an online article in Salon that the tularemia could have come from a terrorist attack or an effort to test U.S. biological safeguards. Critics questioned in the article whether six sensors spread over a wide area would have collected samples that tested positive for tularemia if the pathogen was occurring naturally. The Homeland Security Department and federal public health agencies maintain that the pathogen was natural in origin and was stirred up by participants in the antiwar march and visitors to the book fair. The article “made it sound like they were miles and miles apart and that’s absolutely false,” Stiefel said of the sensors. The sensors in Washington that are known to have collected tularemia are near Judiciary Square, the Lincoln Memorial and Fort McNair on the Potomac River. The Judiciary Square sensor is approximately two miles from the Lincoln Memorial sensor, while the Fort McNair sensor is approximately two miles from the Lincoln Memorial sensor. Stiefel would not disclose the locations of the other three sensors that collected samples of the pathogen. Stanhope said it was imperative to deliver information of possible biological agent contamination quickly to doctors so that they can monitor for signs of infection. “I think this thing raises far more questions than it does answers about the efficacy of the BioWatch system. If I were grading this as an exercise, I would give it an F,” he said. “There has to be a way to get out to the clinical community that there may have been an incident,” he continued. “I think we have missed an opportunity to better understand how to protect that American public the next time this happens. I remain very concerned.” Alan Pearson, biological and chemical weapons director at the Center for Arms Control and Nonproliferation, said he was sympathetic to the government’s dilemma over when the public should be informed. “It’s a tough call for them,” Pearson said. “One the one hand, I would think that if [the response went] as planned, if we actually have an incident, we’re in trouble.” “On the other hand, since they never got a complete signal, at least initially, you don’t want to be alarming people unnecessarily,” he added. Pearson said the incident provides an excellent opportunity for the Homeland Security Department to review its procedures and protocols relating to the BioWatch program. “They have to do some more thinking on how they deal with tularemia” and other biological agents, Pearson said. “Clearly there’s a balance between crying wolf and getting the public the information they need.”
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