Infectious Diseases in Critical Care Medicine

Table 8

Radiographic Findings (

Continued

)

Pathogen

Chest radiographic findings

Comments and other radiologic findings

Tularemia (

F. tularensis

)

Bronchopneumonia that is usually bilateral and may

cavitate. Early papers suggest ulceroglandular form moreoften involves mediastinal lymph nodes and typhoidalform involves the lungs. Later reports suggest the twoforms are radiologically indistinguishable.

Pneumonia occurs in most cases of typhoidal disease and

30% of patients with ulceroglandular disease.

Chest X rays in individuals who developed diseases from

aerosolized organisms were initially normal. Theyprogressed to multifocal segmental or lobar infiltrates.Mediastinal adenopathy was not seen but hilaradenopathy developed in some cases.

A tularemia outbreak caused by aerosolized organisms occurred

on Martha’s Vineyard in 2000. Initial chest X rays werenormal.

Hanta virus pulmonary syndrome:

Sin Nombre virus

Early in the disease, there is interstitial edema, Kerley B

lines, and subpleural edema (even though the patientsare usually hypovolemic). This progresses to bilateralalveolar infiltrates in 48 hours. These patients have50% mortality.

Some patients with less severe disease do not progress to the

stage of interstitial edema.

Viral hemorrhagic fevers [filoviruses

(e.g., Ebola, Marburg) andarenaviruses (e.g., Lassa,Machupo)]

Lobar consolidation is seen in 20% of patients with bacterial

superinfection.

Chest X rays in patients with Argentine hemorrhagic fever are

often normal. Encephalitis common but MR imaging oftennegative.

Extensive pulmonary edema usually represents excessive

fluid therapy.

Rift Valley fever encephalitis: CT revealed multiple cortical

infarcts most prominent in occipital area.

Rabies

Bronchopneumonia on chest X ray. CT reveals non-

enhancing symmetrical hypodensities of the basalganglia.

MRIs are similar in patients with furious and dumb rabies (non-

enhancing, ill-defined, mild hyperintensity in the brain stem,hippocampus, hypothalamus, deep and subcortical whitematter, and deep and cortical gray matter in the consciouspatient.

Rabies after a bite to the arm: MRI will reveal enhancement

of the brachial plexus

In comatose patients, gandolinium enhances the hypothalamus,

brain stem nuclei, spinal cord, gray matter, and intraduralcervical nerve roots.

Category B pathogens

Brucellosis (

Brucella

species)

Pediatric cases: lobar pneumonia or non-resolving

pneumonia. Fatal disease with multifocal liver and lungnodules.

23% complain of cough, but practically none have physical or

radiographic findings. Rare cases of air-space pneumonia,bronchopneumonia, lung abscess, pleural effusion, andempyema reported.

(Continued )

Bioterrorism Infections in Critical Care 461