A 30-year-old man presented to the emergency department with a 3-day history of fever, chills, nausea, vomiting, diarrhea and abdominal pain. The patient's symptoms had progressed rapidly until he had a productive cough with yellow sputum, which led him to visit the emergency department.The patient's medical history included hepatitis C, asthma and cholecystectomy. Results of serologic testing for HIV 4 months earlier had been negative. The patient was taking ipratropium and salbutamol. In addition, he stated that he regularly used both cocaine and morphine intravenously.On physical examination, the patient appeared unwell. Although he was drowsy, he was easily arousable. His temperature was 38.7°C, with a blood pressure of 70/44 mm Hg and a pulse of 93 beats/min. He did not have any rashes, and his oropharynx was unremarkable. He had no cervical, axillary or inguinal lymphadenopathy. His chest examination was unremarkable, except for a mild inspiratory wheeze. The patient's heart sounds were normal, with no additional sounds or murmurs. His abdomen was diffusely tender to palpation, but there was no rebound tenderness or guarding, nor was there evidence of hep at o splen o megaly or palpable masses. His right knee showed signs of recent trauma.The results of initial laboratory investigations showed a leukocyte count of 0.7 (normal 4.0-11.0) × 10 9 /µL and a neutrophil count of 0.4 (normal 2.0-7.5) × 10 9 /µL. Liver enzyme testing showed an alanine aminotransferase concentration of 48 (normal 4-55) U/L and an aspartate aminotransferase concentration of 179 (normal 5-35) U/L. We admitted the patient to hospital, where he received piperacillin-tazobactam for febrile neutropenia; however, his neutropenia spontane ously remitted the following day. His condition responded quickly to aggressive supportive measures, including fluids delivered intravenously. After 1 day, the patient's leukocyte count had risen to 20.7 × 10 9 /µL, and his neutrophil count was 19.1 × 10 9 /µL. Cultures of blood drawn before antibiotics were administered grew Bacillus cereus in 1 of 2 vials after 16 hours, prompting us to add vancomycin to the drug regimen, pending susceptibility testing. Chest radiography showed patchy airspace disease in the lower lobe of the patient's left lung. A computed tomography scan of the abdomen and pelvis showed a normal liver and biliary tree, diverticulosis without diverticulitis, a trace right pleural effusion and a trace amount of free pelvic fluid.
What is your differential diagnosis?a. Mononucleosis secondary to Epstein-Barr virus (EBV) or cytomegalovirus (CMV) b. Acute hepatitis A infection c. Acute HIV infection d. Levamisole toxicity secondary to adulterated cocaine e. Endocarditis secondary to B. cereusWe thought that an infectious agent was the most likely explanation for our patient's unusual symptoms, specifically (c) HIV or (d) B. cereus. Given the unusual presentation of his condition, however, we ordered serologic tests for EBV and CMV, which were negative. Although the results of serologic test...