Clinical Manifestations of Legionnaires' Disease 

 and Recommended Therapy 



William B. Baine 



Legionnaires' disease (LD) has most commonly been recognized as a form of pneumonia. 

 Symptoms of this syndrome usually become apparent 2 to 10 days after known or presumed 

 exposure to airborne Legionnaires" disease bacteria (LDB). The earliest symptoms are malaise, 

 myalgia, and mild headache. A non productive cough is common, but sputum production is 

 sometimes associated with the disease. Within less than a day the patient may experience rapidly 

 rising fever and the onset of chills. Although physical examination of the patient may reveal rales 

 on auscultation, fever to 39°- 41°C (102°-105°F), and relative bradycardia, no physical findings 

 are specific to this disease. Associated manifestations may include confusion, chest pain, abdom- 

 inal pain, imparled renal function, and diarrhea. 



Routine laboratory tests commonly reveal a moderate leukocytosis with a shift to the left in 

 the granulocyte series. Proteinuria, hyponatremia, hypophosphatemia, azotemia, elevated amino- 

 transferase levels, and a high erythrocyte sedimentation rate are often seen in various combina- 

 tions. Radiographs of the chest reveal patchy infiltrates that may progress to extensive consolida- 

 tion. Cavitary pneumonia is uncharacteristic, but some examples have been reported. A case- 

 fatality rate of approximately 15% for sporadic cases has been reported in the United States. 



Two LD case histories are presented below: 



Case History #1. 



A 59-year-old construction worker was hospitalized July 5 in Missouri with a 5-day 

 history of malaise, myalgia, chills, and fever to 105°F after a 2'/2 week vacation trip to 

 Canada, the western United States, and Mexico. On this trip he had gone boating: visited a 

 sawmill, a zoo, and the engine room of a ship: fed birds in a public park: and repaired some 

 malfunctioning air conditioners in a hotel. He did not smoke, and his past medical history 

 was unremarkable except for two episodes of pneumonia in childhood and a case of malaria 

 while serving in the South Pacific during World War II. 



The physical examination was unremarkable except for the presence of fever and of 

 occasional rales in the left lung. 



Admission urinalysis revealed a specific gravity of 1.033, pH 6, 1+ protein, 6-8 white 

 cells, and 3-4 red cells. The admission hematocrit was 44% with a hemoglobin of 14.2 g/dl, 

 and 13,300 white cells/nl. The white cell differential was 72% neutrophils (including 3% 

 bands), 4% monocytes, and 24% lymphocytes with an adequate number of platelets. Blood 

 chemistries were generally within noimal limits. The chest radiograph on admission revealed 

 an infiltrate at the left base. 



He was treated with cephalexin, penicillin, and glucocorticoids and continued to have 

 hectic fevers. Within 3 days the infiltrate at the left base had partially resolved, but new 

 infiltrates were present in the left mid-lung field, the left infraclavicular area, and the right 

 mid-lung field (Figure 1). A lung biopsy perfonned on the I 1 th hospital day revealed 

 consolidation and a severe intlammatory reaction with a significant polymorj^honuclear 

 component. After 8 days in the hospital, the patient became afebrile. Routine attempts to 



