Pittsburgh pneumonia agent: chest film manifestations

Pittsburgh pneumonia agent, Legionella micdadei, is a Gram-negative, weakly acid-fast bacillus, recently recognized as a cause of pulmonary infection in the immunocompromised host. The chest radiographic findings in seven patients with this disease are reported. These consist of single or multiple nodules and segmental infiltrates involving part of all of one or more lobes. A striking feature in this series was the rapid growth of the pulmonary densities.