A 36‐year‐old man living in the United States since 1996 (born in a sub‐Saharan country) presented with 4 days of fever, malaise, watery diarrhea, progressive dyspnea, and dry cough. He subsequently developed slurred speech and ataxia without mental status changes or other neurologic deficit. He had traveled to Boston 2 weeks earlier. He denied recent ill contacts, hiking, lake swimming, insect bites, and exposure to cat feces or ingestion of uncooked meat. He is a nonsmoker, nonalcoholic, non–drug user and denied risky sexual history. Examination was positive for crackles in the right base as well as mild dysarthria. There was no jaundice, meningismus, or focalization. A brain CT was unremarkable. A chest roentgenogram showed a right middle lobe consolidation. Initial studies showed white blood cell count 11.9 × 103/μL, hemoglobin 11.6 g/dL, platelets 137 × 103/μL, Na 131 mEq, ALT 113 U/L, AST 387 U/L, lactate dehydrogenase 988 U/L, and erythrocyte sedimentation rate 119 mm/h. The patient was started on intravenous ceftriaxone, vancomycin, and azithromycin. An electroencephalogram was normal. A brain MRI/MRI revealed an abnormal corpus callosum signal with restricted diffusion, suggestive of acute demyelinating encephalomyelitis (ADEM). Serologies for Chlamydia, Mycoplasma, Rickettsia, Borrelia, and viral hepatitis were negative as well as for cytomegalovirus DNA. Cerebrospinal fluid showed normal glucose and protein with no pleocytosis, with negative Cryptococcus antigen, herpes simplex virus polymerase chain reaction, West Nile virus, and enterovirus. The patient had progressive clinical improvement, and the Legionella urine antigen was positive. HIV was positive, with a viral load of 433,000 copies/mL and CD4 of 364. It was considered that the constellation of symptoms including the pneumonia, fever, neurologic abnormalities, thrombocytopenia, and transaminitis could be explained by Legionnaire's disease in a patient with HIV. The patient was discharged on oral azithromycin and outpatient follow‐up by the HIV clinic.
Legionnaire's disease is a clinical syndrome caused by Legionella sp. Classic clinical presentation is pneumonia, malaise, high feve, and gastrointestinal manifestations. Confusion and neurologic abnormalities occur 53% of the time. More dramatic clinical presentation occurs in the immunosuppressed such as our patient. Laboratory abnormalities are nonspecific including thrombocytopenia, transaminitis, hypophosphatemia, and hyponatremia. Chest x‐ray findings are nonspecific although most commonly presents as a patchy unilobar infiltrate. The urinary antigen test has several advantages: it is readily available, and test positivity persists even during administration of antibiotic therapy. Its major disadvantage is that it is specific for L. pneumophila serogroup 1 only (although this accounts for 90% of communityacquired Legionella infections in the United States).
The hospitalists should be aware of the complex clinical manifestations of Legionnaire's disease to initiate early treatment while narrowing the differential diagnoses.
M. Auron ‐ none; H. B. Freyle ‐ none; V. J. Velez ‐ none; D. El‐Bejjani ‐ none; M. Y. Duran‐Castillo ‐ none
To cite this abstract:Freyle H, El‐Bejjani D, Duran‐Castillo M, Velez V, Auron M. A Challenging Clinical Constellation: The Exquisite Presentation of Legionnaire's Disease. Abstract published at Hospital Medicine 2011, May 10-13, Dallas, Texas. Abstract 280. Journal of Hospital Medicine. 2011; 6 (suppl 2). https://www.shmabstracts.com/abstract/a-challenging-clinical-constellation-the-exquisite-presentation-of-legionnaires-disease/. Accessed November 18, 2019.