A reasonable defense against an airborne anthrax attack requires more aggressive action by the U.S. government than now planned, says a study published the week of March 17 in the Proceedings of the National Academy of Sciences (PNAS). The government is relying too heavily on biosensors to pinpoint an anthrax attack and not doing enough to get large quantities of drugs and medical personnel to affected areas within hours, says the team headed by Lawrence Wein of Stanford University's Graduate School of Business.
Wein, who is professor of operations, information and technology at the Business School, and his fellow researchers considered the possibility that drug intervention against anthrax could start earlier if the attack was detected by biosensors – devices that sniff out anthrax spores. Although the federal government is spending many millions of dollars to develop biosensors, their use alone is insufficient and could create a false sense of security, says Wein. We would also need aggressive distribution of prophylactic antibiotics, such as Cipro, and the ability to develop a large capacity of emergency medical care for rapid deployment in affected areas. Huge numbers of extremely expensive sensors would have to be spread throughout the nation in order to be in proximity to where the spores are released and to detect them, which is unrealistic. "There is still no substitute for getting people antibiotics and medical care as fast as possible," he said.
In earlier work published by the same researchers in the Aug. 6, 2002, issue of the PNAS, they argued for speedy mass vaccinations as soon as a case of smallpox appears in a population rather than the more time-consuming practice recommended by the government of identifying individuals the victim had been in contact with, locating them and then vaccinating them.
"Our country has made great strides in the past year at preparing for a potential smallpox attack," Wein said. "Although smallpox is a contagious disease, it is also a slower moving disease, and, as my colleagues and I showed in a study published last summer, post-attack mass vaccination would nip even a large smallpox attack in the bud. Unfortunately, controlling the consequences of an anthrax attack may be a bigger challenge."
Although anthrax isn't contagious like smallpox, it is a swift and durable pathogen. Treatment for those exposed must begin within hours of the first cases being diagnosed, rather than days as in the case of smallpox. Without antibiotic intervention, 90 percent of people exposed to the inhalation form of anthrax will die. Because anthrax is durable, lethal and available, it is a likely weapon in a bioterrorist attack. "It can survive an explosion, which makes it ideal for weaponization," Wein said.
Wein's coauthors in the anthrax study are David L. Craft, a doctoral student at the MIT Operations Research Center, and Edward H. Kaplan, professor of management sciences at Yale School of Management. They analyzed a variety of possible responses to a scenario in which two pounds of anthrax are dropped in a city of 11 million people (the approximate size of New York City) and 1.5 million are infected. Based on an analysis of more than 30 years of data, including a 1993 report from the now-defunct congressional Office of Technology Assessment, the authors propose the following as a reasonable scenario:
In their base case, every person in every neighborhood, in which one person shows symptoms and is promptly diagnosed, must take antibiotics to survive. However, by the time all of the drugs are distributed, within four days, 123,000 people in the city of 11 million would die.
The reason: If people don't get antibiotics quickly to keep the infection from developing, too many will become symptomatic and will overwhelm hospitals and medical facilities. Most will die before they get medical aid. Five of the 11 inhalation anthrax patients in the 2001 attacks on the U.S. postal system died despite being treated aggressively by teams of doctors far larger than would be available in a more widespread attack.
Wein suggests a four-pronged proposal for avoiding such a catastrophe. First, the person in charge – either President Bush, individual state governors or city mayors – needs to act decisively: As soon as a case is detected everyone in the area needs to be informed and directed to where drugs can be administered.
"The first people develop symptoms within two days of exposure, and many more would develop symptoms over the next week," said Wein. "Our response needs to be measured in hours, not in days or weeks." In addition, antibiotics need to be delivered as quickly as possible, and the authors recommend distributing them prior to proof that any attack has occurred. "Give it to the people now so that they can just turn on CNN and wait for Secretary Ridge to tell the people in their region to take their Cipro now," he recommended.
If this is deemed too risky, then Washington needs to set a goal of distributing antibiotics within 12 hours. "If we can vote in a single day, we should be able to hand out pills in a day," he said. This might mean changing the laws so that nonmedical personnel can distribute the antibiotics.
Third, the authors note that it is important to make people understand that, if they are in the exposure region, they must take the full course of the antibiotic, or risk development of symptoms and ultimately death. Finally, a drastic increase in surge capacity of medical professionals is needed to ease treatment bottlenecks at hospitals and clinics. According to Wein's calculations, even if antibiotics are distributed before an attack, to reduce the death toll in their base scenario from 123,000 to 1,000 would require one medical professional for every 700 people in the affected population.
Wein argues that this ratio can be achieved only by training non-emergency medical professionals; making maximal use of military and federal resources such as the Red Cross, the National Guard, and the VA hospitals; and developing a national volunteer system of pulmonary specialists who – acting much as a volunteer fire department – would get in airplanes and fly to afflicted regions. Wein, who is an expert in the theory of queues and in the management of manufacturing and service operations, said: "I think we need to tap into the large number of brave and selfless medical professionals in this country who are willing to do this.
"Deterrence was effective in the Cold War, but it is not going to work against terrorists. And counterproliferation – that is, getting the weapons out of the hands of the enemy – is very difficult in the case of biological weapons. So our security against a biological terror attack rests in a very strong emergency response."
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