Critical Care Medicine-Infections and Immunologic Disease>>>>>Systemic Infections
Question 1#

A 26-year-old man presents to the emergency room with fevers and headache for the last 2 days. His temperature is 39.1°C, heart rate 123 beats/min, blood pressure 88/54 mm Hg, and respiratory rate 28 breaths/min. He appears diaphoretic and pale on examination but has no rash and no other abnormal physical findings. His white blood cell count is 3.9 × 10 9 /L, hemoglobin 5.6 g/dL, platelet count 112,000/µL, and creatinine 2.7 mg/dL. He is oliguric. He is a medical student and returned from Uganda 6 days ago, where he has been conducting research for the last year. He reports no sexual contacts within the last six months.

Which of the following is the MOST likely cause of his acute illness?

A. Strongyloides hyperinfection syndrome
B. Zika virus infection
C. Plasmodium falciparum malaria
D. Brucellosis

Correct Answer is C


Correct Answer: C

Malaria is the most common infection among returned travelers, and P. falciparum is the malaria species causing the vast majority of malaria infections in travelers to sub-Saharan Africa. Diagnosis is traditionally made using thick and thin peripheral blood smears but requires an experienced microscopist. Rapid diagnostic tests using immunochromatography to detect malaria antigens are also commonly used for diagnosis. Because malaria is the most common infection among returned travelers, this is the most likely cause of this patient’s illness. The illness described is less likely to be Strongyloides hyperinfection syndrome (Answer A), which usually presents in an immune-suppressed patient, often with a high white blood cell count and signs of meningitis. Zika virus infection (Answer B) is often mild or asymptomatic and does not fit well with the scenario of extremis presented here. Brucellosis (Answer D) is usually an indolent infection presenting as fever of unknown origin with malaise and mylagias. 


  1. Freedman DO, Weld LH, Kozarsky PE, et al. Spectrum of disease and relation to place of exposure among ill returned travelers. N Engl J Med. 2006;354:119-130.
  2. Wilson ME, Weld LH, Boggild A, et al. Fever in returned travelers: results from the GeoSentinel Surveillance Network. Clin Infect Dis. 2007;44:1560-1568.