Avian influenza as a biological weapon: Threat assessment and public health alert

Highly pathogenic (HP) H5N1 avian influenza (AI) has killed 63% of infected people worldwide since 1997 (WHO, 2008a) and represents an attractive bioterrorism agent for terrorist organizations and other non-state adversaries to harm the United States and its interests. Mortality disease modeling using the Centers for Disease Control and Prevention's (CDC) FluAid software demonstrated that HP H5N1 avian influenza, when compared to B. anthracis (anthrax), caused similar mortality (approximated between 5 and 9 deaths) when modeled with comparable conditions, attack rates (0.25%), and environmental settings as the 2001 anthrax letter attacks.;A second scenario estimated overall mortality for a deliberate introduction of H5N1 influenza virus with high attack rates (ranging from 15 to 35%) and high mortality rates (0.1%, 2.5%, and 32%) at pandemic levels (ranging from 107,575 to 136,741,654). The United States, through the Centers for Disease Control and Prevention (CDC), should lead the world in properly categorizing H5N1 influenza and other novel influenza A viruses as Category A agents for bioterrorism. Classifying H5N1 influenza and other novel influenza A viruses as Category A agents is justified because of their potential for high mortality (63% for H5N1) (WHO, 2008a), availability for weaponization, ease of production, and the overall lack of widely available vaccine protection. The proper classification of H5N1 and other novel influenza A viruses as Category A agents by the CDC could potentially impact future R&D biodefense efforts, thereby providing more effective medical countermeasures for the specific and dangerous threat of influenza.