Table 2.

Clinical features of legionnaire's disease

Organ	Common Features	Uncommon Features	Argues against involvement of legionnaire's disease
Clinical features
CNS	Headache, mental confusion, dullness, lethargy	Dizziness	Meningeal signs, seizures
HEENT	None	Vertigo	Sore throat, ear pain, bullous myringitis, otitis media
Cardiac	Relative bradycardia	Legionella endocarditis	Emboli to heart, joints, lungs, spleen, CNS
GI	Loose stools, watery diarrhoea	Abdominal pain	Hepatic tenderness, peritoneal signs
Renal	↑ Creatinine	Acute renal failure	CVA tenderness, chronic renal failure
Laboratory features
CSF	Normal	Mild pleocytosis	RBCs, ↓ glucose,↑ lactic acid
WBC count (blood)		Leukocytosis	Leukopenia thrombocytopeniaThrombocytosis,
Gram stain (sputum)	No bacteria	Few mononuclear cells, mixed flora	PMN predominance, predominant organismPurulent sputum, single
Pleural fluid	Exudative pattern	↑ WBCs	RBCs,↓ pH, ↓ glucose
SGOT/SGPT	Mildly elevated (< 2 × normal)	Moderately elevated (> 2 × normal)	Markedly elevated (> 10 × normal)
Urine analysis	Microscopic haematuria	Proteinuria Myoglobulinuria	Gross haematuria, pyuria, hemoglobinuria

CN, cranial nerve; CNS, central nervous system; CSF, cerebrospinal fluid; CVA, costovertebral angle; GI, gastrointestinal; HEENT, head, eyes, ears, nose and throat; LUQ, left upper quadrant; PVE, prosthetic valve endocarditis; RBC, red blood cell; RLQ, right lower quadrant; SBE, subacute bacterial endocarditis; WBC, white blood cell.