Prepositioning Antibiotics for Anthrax
If terrorists released Bacillus anthracis
over a large city, hundreds of thousands of people could be at risk of the deadly disease anthrax—unless they had rapid access to antibiotic medical countermeasures (MCM). Anthrax is an infectious disease caused by B. anthracis
spores that can be inhaled, be ingested, or come into contact with the skin. Inhalational anthrax is considered the most severe bioterrorism threat because the spores can travel significant distances through the air while remaining infectious, and it has the highest mortality rate, approaching 100 percent if untreated.
During the past decade, public health authorities and other leaders have significantly enhanced their plans for rapidly delivering MCM to a large number of people following an anthrax attack. Many public health authorities and other policy experts fear, however, that the nation’s current systems and plans are insufficient to respond to the most challenging scenarios, such as a very large-scale anthrax attack or an attack on multiple cities.
As part of efforts underway nationwide to improve the nation’s ability to rapidly distribute and dispense MCM, the Office of the Assistant Secretary for Preparedness and Response (ASPR), within the U.S. Department of Health and Human Services (HHS), commissioned the Institute of Medicine (IOM) to examine the potential uses, benefits, and disadvantages of strategies for prepositioning antibiotics. Prepositioning involves storing antibiotics close to or in the possession of the people who would need rapid access to them should an attack occur. These prepositioning strategies—intended to help ensure timely access to antibiotics in the event of an attack—would complement existing plans that rely heavily on more centralized stockpiles. Prepositioning is just one component of a broad effort to enhance the nation’s ability to prevent an attack and mitigate the effect in the event that one does occur.
Delivering Antibiotics on Time
Antibiotics are most effective at preventing anthrax if taken before symptoms begin to occur. Based on its review of the literature, the IOM committee appointed to this task finds that the earliest sign of inhalational anthrax symptoms will likely occur four days or later after an attack. It may take a day or two—if not more—to detect that an attack has occurred and for public health officials to decide that antibiotics should be dispensed to people who may have been exposed. To prevent illness, therefore, public health officials must act quickly to distribute and dispense antibiotics in the remaining time before symptoms appear.
The Centers for Disease Control and Prevention (CDC) and state and local jurisdictions currently aim to dispense antibiotics to the entire population within 48 hours after the decision is made to dispense antibiotics. The committee finds—given the limited evidence available—that this goal appears to be appropriate as long as the attack is detected soon after it occurs. Improvements to the dispensing time, however, may provide additional protection against unforeseen delays.