title: Pathology and pathogenesis of bioterrorism-related inhalational anthrax.
abstract: During October and November 2001, public health authorities investigated 11 patients with inhalational anthrax related to a bioterrorism attack in the United States. Formalin-fixed samples from 8 patients were available for pathological and immunohistochemical (IHC) study using monoclonal antibodies against the Bacillus anthracis cell wall and capsule. Prominent serosanguinous pleural effusions and hemorrhagic mediastinitis were found in 5 patients who died. Pulmonary infiltrates seen on chest radiographs corresponded to intraalveolar edema and hyaline membranes. IHC assays demonstrated abundant intra- and extracellular bacilli, bacillary fragments, and granular antigen-staining in mediastinal lymph nodes, surrounding soft tissues, and pleura. IHC staining in lung, liver, spleen, and intestine was present primarily inside blood vessels and sinusoids. Gram's staining of tissues was not consistently positive. In 3 surviving patients, IHC of pleural samples demonstrated abundant granular antigen-staining and rare bacilli while transbronchial biopsies showed granular antigen-staining in interstitial cells. In surviving patients, bacilli were not observed with gram's stains. Pathological and IHC studies of patients who died of bioterrorism-related inhalational anthrax confirmed the route of infection. IHC was indispensable for diagnosis of surviving anthrax cases. The presence of B. anthracis antigens in the pleurae could explain the prominent and persistent hemorrhagic pleural effusions.
authors.affiliation: Infectious Diseases Pathology Activity, Division of Viral Rickettsial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: Jeannette
authors.initials: J
authors.lastname: Guarner
authors.forename: John A
authors.initials: JA
authors.lastname: Jernigan
authors.forename: Wun-Ju
authors.initials: WJ
authors.lastname: Shieh
authors.forename: Kathleen
authors.initials: K
authors.lastname: Tatti
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Flannagan
authors.forename: David S
authors.initials: DS
authors.lastname: Stephens
authors.forename: Tanja
authors.initials: T
authors.lastname: Popovic
authors.forename: David A
authors.initials: DA
authors.lastname: Ashford
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Perkins
authors.forename: Sherif R
authors.initials: SR
authors.lastname: Zaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000881:Anthrax / Q000382:microbiology / Q000473:pathology*; D001408:Bacillus anthracis / Q000302:isolation & purification*; D023482:Bioterrorism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019570:Inhalation Exposure; D008168:Lung / Q000473:pathology; D008198:Lymph Nodes / Q000382:microbiology / Q000473:pathology; D008297:Male; D008482:Mediastinum / Q000382:microbiology / Q000473:pathology; D008875:Middle Aged; D016273:Occupational Exposure; D010994:Pleura / Q000382:microbiology / Q000473:pathology; D010996:Pleural Effusion / Q000382:microbiology / Q000473:pathology; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000473:pathology*; D014481:United States