[Encephalitis without pneumonia caused by Legionella bozemanii]

Legionnaire disease (LD) is characterized by a clinical picture of pneumonia and is usually accompanied by multisystem involvement. Neurologic manifestations tend to appear concurrently with, or soon after the onset of fever. Cases in which neurologic manifestations precede the development of pneumonia are exceedingly rare. We recently treated 3 patients with LD who presented with a clinical picture of severe viral encephalitis without pneumonia. There were high serum titres of IgG and IgM antibodies against several Legionella species. However, a positive reaction in the spinal fluid was detected only against L. bozemanii. All 3 patients were discharged without sequellae. We suggest that LD should be included in the differential diagnosis of viral encephalitis.