July 27, 2009 By Blake Harris
Photo: U.S. Postal Inspectors during their basic training in HAZMAT suits.
According to a new computer simulation study, a large airborne anthrax attack in any major metropolitan area could affect more than a million people, necessitating their treatment with powerful antibiotics. But in order for such a response to be effective, quick detection and treatment are essential. Any delay beyond three days would overwhelm hospitals with critically ill people, says by Dr. Nathaniel Hupert, associate professor of public health and medicine at Weill Cornell Medical College and lead author of the study.
"No matter how well-organized and prolonged a treatment program is, it must be quickly implemented. In fact, our analysis shows that time-to-treatment is roughly twice as important as the duration of the distribution program," says Dr. Hupert in a news statement coinciding with the study's release.
"Crucial to rapidly implementing a treatment program is early detection, including thorough use of advanced biosurveillance technologies and live, person-to-person communication," adds Dr. Hupert, who is also director of the new Preparedness Modeling Unit at the U.S. Centers for Disease Control and Prevention (CDC). "But most important of all are multilateral diplomatic efforts to prevent bioterrorist attacks from ever happening."
The study predicts that a campaign initiated two days after exposure would protect as many as 87 percent of exposed individuals from illness -- a rate considered successful by the CDC. Each additional day needed to complete the campaign would result in an average of up to 2.9 percent more hospitalizations in the exposed population. And each extra day of delay to the start of the program beyond two days would result in up to 6.5 percent more hospitalizations.
Anthrax attack scenarios typically involve the release of one kilogram of weaponized anthrax from a small airplane flying over a major city. The invisible powder could be inhaled by thousands or hundreds of thousands, who would start becoming sick anywhere from 24 hours to a week or more after the attack. With appropriate and timely administration of an antibiotic treatment program, exposed individuals would be spared from developing inhalational anthrax infection.
Dr. Hupert is also co-author the first-ever position paper of the Society for Medical Decision Making. This too appears in the July/August edition of the journal Medical Decision Making. The study tackles a challenge in the emerging field of disaster response planning -- the confusing variety of approaches to computer modeling.
Computer modeling is increasingly used to predict and plan for disaster response. But because there are so many different modeling methods, according to the paper, researchers have been unable to compare results between models.
Dr. Hupert and his co-authors looked at various approaches and recommend several best practices: models should address real-world problems, be designed for maximum usability, strike the appropriate balance between simplicity and complexity, include appropriate outcomes, and be designed to evaluate the many uncertainties inherent in disaster response. Finally, the authors stress that clear and complete reporting of model results is particularly critical for disaster response models.
The studies in the July/August edition of the journal Medical Decision Making can also be found at http://mdm.sagepub.com/cgi/rapidpdf/0272989X09341389v1
Photo by Rev. Xanatos Satanicos Bombasticos. CC Attribution-Noncommercial-Share Alike 2.0 Generic