Jon Temte, MD, PhD
Andrew R. Zinkel, BS
Advanced Research Training Grant – American Academy of Family Physicians, Summer Research and Clinical Assistantship Program with support through the U.W. Department of Family Medicine and the Wisconsin Academy of Family Physicians
Inhalation anthrax is a rare disease with non-specific initial symptoms. Following covert release of anthrax spores, primary care and emergency physicians will be the first to encounter and evaluate cases, assign diagnoses, and provide initial medical management. Systems designed to provide early detection must take into consideration the diagnostic and management approaches of frontline physicians.
To define the primary care differential diagnosis for inhalation anthrax and evaluate the management of cases based on the initial clinical presentations of eleven bioterrorism-associated cases.
Mailed survey distributed between May 6 and July 15, 2002 consisting of three randomly chosen clinical case vignettes describing patients that had inhalation anthrax (n=11), influenza A (n=2) or Legionella pneumonia (n=1). Cases included basic demographic data, past medical history, presenting symptoms, physical findings and results of blood analysis, but were modified so as to include only information that would be available in a primary care setting. Setting and Participants-Nationwide random sampling of 665 clinically active members of the American Academy of Family Practice who completed residency training before 2001 and practiced all types of ambulatory care.
Main Outcome Measures
Most likely non-anthrax diagnoses and rates of hospitalization, chest x-ray, blood culture, and antibiotic use for each of the fourteen clinical case vignettes.
A response rate of 36.9% was obtained following three distributions of the survey. Diagnoses for inhalation anthrax wer grouped into a total of 35 diagnostic categories, with pneumonia (42%), influenza (10%), viral syndrome (9%), sepsis (8%), bronchitis (7%), CNS infection (6%), and gastroenteritis (4%), accounting for 86% of all diagnoses. The rates of hospitalization, chest x-ray, blood culture, and antibiotic initiation were 57%, 84%, 55%, and 63%, respectively. Initial management of the patient would have helped to detect anthrax in approximately 92% of the cases.
Although initial symptoms of inhalation anthrax were translated into a wide variety of diagnoses, pneumonia was by far the most frequent diagnosis. Current family practice management of most patients with symptoms similar to inhalation anthrax would aid in the identification of a cover bioterrist event.