Consensus statement ularemia, a bacterial zoono

©2001 American Medical Association. All rights reserved.

(Reprinted) JAMA, June 6, 2001—Vol 285, No. 21 2765

rapidly to severe pneumonia, with co- pious watery or purulent sputum pro- duction, hemoptysis, respiratory insuf- ficiency, sepsis, and shock.4 Inhalational anthrax would be differentiated by its characteristic radiological findings of prominent symmetric mediastinal wid- ening and absence of bronchopneumo- nia.2 As well, anthrax patients would be expected to develop fulminating, toxic, and fatal illness despite antibiotic treat- ment.29 Milder forms of inhalational tu- laremia could be clinically indistin- guishable from Q fever; establishing a diagnosis of either would be problem- atic without reference laboratory test- ing. Presumptive laboratory diag- noses of plague or anthrax would be expected to be made relatively quickly, although microbiological confirma- tion could take days. Isolation and iden- tification of F tularensis using routine laboratory procedures could take sev- eral weeks.

Once a substantial cluster of cases of

inhalational tularemia had been iden- tified, epidemiological findings should suggest a bioterrorist event. The abrupt onset and single peak of cases would implicate a point-source exposure with- out secondary transmission. Among ex- posed persons, attack rates would likely

be similar across sex and age groups, and risk would be related to degree of exposure to the point source (Table 1). An outbreak of inhalational tularemia in an urban setting should trigger a high level of suspicion of an intentional event, since all reported inhalational tu- laremia outbreaks have occurred in ru- ral areas.