June 10, 2014 Grand Rounds

Case 1: Malaria in a 24-year old returned traveler from Africa and Saudi Arabia

1. Important differential diagnoses in a returned traveler who presents with fever include: malaria, dengue, typhoid fever, rickettsial infection, leptospirosis, and N. meningitidis.

2. Since the patient here presented with fever and prominent headache, African trypanosomiasis (African sleeping sickness) was also included in the differential diagnoses. It was pointed, however, that this diagnosis is very rare. In a cohort of more than 17,000 patients from the GeoSentinel data, only one had African trypanosomiasis. This article can be found here.

3. Coartem (artemether/lumefantrine) is the oral agent of choice for uncomplicated malaria. Malarone (atovaquone/proguanil) is an alternative oral agent. In this patient, Malarone, which was the initial drug administered, did not clear the parasetemia even after 4-5 days of treatment. Parasetemia eventually cleared after switching the medication to Coartem.

4. How soon should we expect clearance of parasetemia with the use of Malarone? In a single study, the use of Malarone led to complete clearance of the parasetemia in all patients on day 3 of treatment. 

5. Atovaquone resistance is easily inducible in vitro. We don't see it a lot in clinical practice because mutations that lead to atovaquone resistance render the parasite less fit.


Case 2: Mycoplasma infection associated with multiple deep vein thromboses and pulmonary embolism in a 14-year old immunocompetent person

1. Remember that Mycoplasma infection can induce a procoagulant state (elevated cardiolipin), much like infection with parvovirus B19, tuberculosis, EBV, CMV, etc.). More 23 case reports have been published in the literature.


Case 3: Extensive cutaneous Alternaria infection in a patient with multiple episodes of bloodstream infections

1. Repeated episodes of bloodstream infection, in the absence of endocarditis, gastrointestinal pathology, central lines, or prosthetic devices should behoove clinicians to do a thorough dermatologic examination. This patient presented with extensive cutaneous Alternaria infection that caused him to develop burn-like lesions enough to compromise cutaneous barrier against infection.

2. The treatment of choice for Alternaria is amphotericin. Posaconazole and voriconazole also display good activity. Surprisingly, some Alternaria sp. have low MIC's to the echinochandins.