Psittacosis in the elderly.

Six elderly patients with serological evidence of psittacosis but atypical syndromes are described. These cases illustrate the difficulties in diagnosing this infection in the old. Four patients were febrile and three had lesions visible on X-ray of the chest. Three died, in one acute toxic viral myocarditis seemed the cause. All were treated with tetracycline, which must be given generously. Psittacosis infection would probably be more commonly diagnosed in the old if serological examinations were carried out in old people immediately on their administration to hospital because of a severe febrile illness. Serological tests appear clearly to be the most certain means of identifying psittacosis in patients with multiple pathology.