[Legionnaires' disease with acute respiratory insufficiency. Clinical and biological characteristics, comparison with pneumococcal pneumonia].

OBJECTIVES

Legionnaires' disease is one of the main etiologies of bacterial pneumonias because of its frequency as well as its potential severity. The therapeutic choice implies the need to look for distinctive clinical, biological or radiological signs, due to the unreliability of rapid immunological criteria. Pneumococcus is the first cause of bacterial pneumopathy. Thus, identifying the distinctive signs between these two etiologies may be necessary.

METHODS

In our restrospective study, nine Legionnaires' disease-related pneumonias were compared with nine pneumococcus-related pneumonias with acute respiratory failure and comparable level of severity. Patients were recruited over a two year period in a medical intensive care unit.

RESULTS

Four criteria were found more frequently in pneumonia related to Legionnaires' disease: high-grade fever at the time of admission, elevated transminases, presence of Miller's criteria (converging clinical and biological signs) and increasing creatine kinase.

CONCLUSION

In patients with severe pneumonia, both Pneumococcus and Legionella should be entertained as possible diagnoses before starting treatment. A prospective analysis of precise diagnostic criteria is needed to distinguish between these two bacterial diseases.