A 60-year-old man comes to the office due to fever, shaking chills, diaphoresis, severe muscle pains, nausea, headache, and dark urine for the past 3 days. His other medical problems include chronic obstructive pulmonary disease (COPD), hypertension, and hyperlipidemia. The patient was admitted to the hospital 3 weeks ago for COPD exacerbation. His hospital course was complicated by bright red blood per rectum, for which he received 3 units of packed red blood cells. The bleeding stopped spontaneously and was attributed to diverticulosis. The patient's daily medications include hydrochlorothiazide, albuterol, and simvastatin. He just completed a 3-week corticosteroid taper. He lives in Rhode Island.
The patient's temperature is 39.8 C (103.6 F), blood pressure is 106/64 mm Hg, pulse is 108/min, and respirations are 18/min. Physical examination shows no skin rashes or joint swelling. There is no lymphadenopathy. His lungs are clear to auscultation. Heart sounds are normal. The remainder of the examination is unremarkable.
Laboratory results are as follows:
Coagulation studies are normal. Urinalysis and microscopy are positive for urobilinogen and negative for blood and erythrocytes. Chest x-ray reveals no infiltrates.
Which of the following would be the most helpful for making the diagnosis in this patient?

Question

A 60-year-old man comes to the office due to fever, shaking chills, diaphoresis, severe muscle pains, nausea, headache, and dark urine for the past 3 days.  His other medical problems include chronic obstructive pulmonary disease (COPD), hypertension, and hyperlipidemia.  The patient was admitted to the hospital 3 weeks ago for COPD exacerbation.  His hospital course was complicated by bright red blood per rectum, for which he received 3 units of packed red blood cells.  The bleeding stopped spontaneously and was attributed to diverticulosis.  The patient's daily medications include hydrochlorothiazide, albuterol, and simvastatin.  He just completed a 3-week corticosteroid taper.  He lives in Rhode Island.
The patient's temperature is 39.8 C (103.6 F), blood pressure is 106/64 mm Hg, pulse is 108/min, and respirations are 18/min.  Physical examination shows no skin rashes or joint swelling.  There is no lymphadenopathy.  His lungs are clear to auscultation.  Heart sounds are normal.  The remainder of the examination is unremarkable.
Laboratory results are as follows:
 Coagulation studies are normal.  Urinalysis and microscopy are positive for urobilinogen and negative for blood and erythrocytes.  Chest x-ray reveals no infiltrates.
Which of the following would be the most helpful for making the diagnosis in this patient?

Quizplus · Accepted Answer

11ec193a_9851_ae41_853d_1193d196faa0_MD0002_00 This patient has an acute febrile illness with hemolytic anemia (indirect hyperbilirubinemia, urinalysis with urobilinogen), thrombocytopenia, abnormal liver function tests, normal renal function and mental status, and severe myalgias. Given the clinical presentation, laboratory findings, history of a recent blood transfusion, and where the patient lives (endemic for tickborne diseases), transfusion-transmitted babesiosis (TTB) should be suspected. Blood banks usually do not screen for diseases such as malaria and babesiosis, so asymptomatic blood donors in endemic areas may carry Babesia in their blood. Babesiosis is more common in men, individuals age >50, and those with asplenia, HIV, malignancy, or immunosuppression (can have up to 20% parasitemia). Symptoms (fever, headaches, myalgias) typically develop 1-6 weeks following a tick bite, and up to two-thirds of patients cannot recall being bitten. TTB is less common but being increasingly recognized (1 case for every 15,000 red blood cell transfusions in Rhode Island). Definitive diagnosis is with thin peripheral blood smear examination (showing parasites within the red blood cells); polymerase chain reaction testing may be useful for low parasitemia. Babesia microti does not grow well in blood cultures (Choice A). Mild babesiosis can be treated with azithromycin plus atovaquone (preferred) or oral clindamycin and quinine. Severe illness requires hospitalization with intravenous clindamycin and oral quinine. parasites within the red blood cells Other differential diagnoses can be excluded based on the findings. Coagulation studies are normal, making disseminated intravascular coagulation unlikely. Thrombotic thrombocytopenic purpura is unlikely given normal creatinine, absence of hematuria, and severe myalgias. Delayed hemolytic reactions with a positive Coombs test are sometimes seen in patients within a month of a transfusion, but they usually present with mild hemolysis and low-grade fever rather than high fevers, significant hemolysis, and thrombocytopenia (Choice B). (Choice C) Hemoglobin electrophoresis detects hemoglobinopathies, which usually present with microcytic anemia. This patient's normal mean corpuscular volume makes this unlikely. (Choice E) This patient's elevated transaminases in the setting of anemia and indirect hyperbilirubinemia reflect a hemolytic process. Viral hepatitis, typically associated with markedly elevated transaminases, is unlikely. Educational objective: Babesiosis usually presents as a flu-like illness with hemolytic anemia in susceptible patients (eg, asplenic, age >50, immunocompromised) who travel to tickborne endemic areas. Transfusion-associated babesiosis is also becoming increasingly common. Treatment for mild babesiosis includes azithromycin plus atovaquone (preferred) or oral clindamycin plus quinine. Severe disease requires hospitalization with intravenous clindamycin plus quinine. __________ References: Babesiosis diagnosis and treatment (http://www.ncbi.nlm.nih.gov/pubmed/12804380) Transfusion-associated babesiosis in the United States: a description of cases. (http://www.ncbi.nlm.nih.gov/pubmed/21893613)

A 60-Year-Old Man Comes to the Office Due to Fever