A 42-year-old man comes to the hospital with a 4-day history of periodic fever, chills, headache, and myalgias. For the past day, he also had mild abdominal discomfort, nausea, and vomiting. The patient has no chest pain, cough, dyspnea, or diarrhea. He returned from an African safari 2.5 weeks ago, and family members who traveled with him have no symptoms. The patient has no past known medical problems. His temperature is 39.4 C (103 F), blood pressure is 122/70 mm Hg, and pulse is 114/min and regular. On examination, he is diaphoretic and uncomfortable. There is mild pharyngeal erythema without exudates or lymphadenopathy. Cardiopulmonary examination is normal. There is no neck stiffness. The abdomen is soft with mild generalized tenderness and splenomegaly. He has no skin rash. Neurologic examination is normal. Laboratory results are as follows:
Chest x-ray reveals no abnormalities. Which of the following interventions could have prevented his current condition?

Question

A 42-year-old man comes to the hospital with a 4-day history of periodic fever, chills, headache, and myalgias.  For the past day, he also had mild abdominal discomfort, nausea, and vomiting.  The patient has no chest pain, cough, dyspnea, or diarrhea.  He returned from an African safari 2.5 weeks ago, and family members who traveled with him have no symptoms.  The patient has no past known medical problems.  His temperature is 39.4 C (103 F), blood pressure is 122/70 mm Hg, and pulse is 114/min and regular.  On examination, he is diaphoretic and uncomfortable.  There is mild pharyngeal erythema without exudates or lymphadenopathy.  Cardiopulmonary examination is normal.  There is no neck stiffness.  The abdomen is soft with mild generalized tenderness and splenomegaly.  He has no skin rash.  Neurologic examination is normal. Laboratory results are as follows:
 Chest x-ray reveals no abnormalities.  Which of the following interventions could have prevented his current condition?

Quizplus · Accepted Answer

Explanation: This patient recently traveled to sub-Saharan Africa and developed an acute febrile illness about 2 weeks after his return. The constellation of fevers, headaches, and laboratory findings with thrombocytopenia raises suspicion for malaria, specifically infection withPlasmodium falciparum. A peripheral blood smear is useful in establishing the diagnosis. Antimalarial prophylaxis, which generally needs to be started in advance of a trip and continued for some time after a traveler's return, helps minimize the risk of infection. The specific regimen depends on the patient and parasite resistance patterns at the travel destination; the most recent guidelines are updated on the Centers for Disease Control and Prevention website. specific regimen The differential diagnosis for fever in a returning traveler depends on geographic epidemiology and is often divided into 3 categories (with some overlap): Early incubation period (<10 days) infections include typhoid fever, dengue fever, chikungunya, influenza, and legionellosis Medium incubation period (1-3 weeks) infections include malaria, typhoid fever, leptospirosis, schistosomiasis, and rickettsial disease Longer incubation period (>3 weeks) infections include tuberculosis, leishmaniasis, and enteric parasitic infections. (Choice A) Malaria is not transmitted from person to person. Neisseria meningitidis can be present in areas of sub-Saharan Africa, and close contact places individuals at risk. However, this patient has no findings suggestive of meningitis (no neck stiffness, no skin rash, no altered mental status), and the incubation period for bacterial meningitis is typically 10 days. (Choice B) Consumption of unbottled water and uncooked food can result in transmission of a number of enteric infections, including typhoid fever and hepatitis A. However, this patient's clinical presentation is more consistent with malaria than typhoid fever (stepwise fever, relative bradycardia, rose spots) or hepatitis A (jaundice, elevated transaminases). Gastrointestinal symptoms such as nausea and vomiting (as well as diarrhea) can occur with malaria. (Choice D) Malaria is not a sexually transmitted infection (STI). HIV, syphilis, gonorrhea/chlamydia, herpes simplex virus, and other infections should be considered when an STI diagnosis is suspected in a returning traveler with pertinent symptoms (eg, urethritis/cervicitis, inguinal lymphadenopathy). (Choice E) There are no antimalarial vaccines currently available. Depending on their destination, travelers may opt for vaccination against yellow fever (required for some countries), typhoid fever, hepatitis A, and other diseases. Educational objective: Malaria should be considered as a differential diagnosis for fever in travelers returning from sub-Saharan Africa, including those who did not complete an appropriate prophylaxis course. Diagnosis is established with a peripheral blood smear. References: Fever in the returning traveler. (http://www.ncbi.nlm.nih.gov/pubmed/24176472) Infectious disease emergencies in returning travelers: special attention to Falciparum malaria, dengue fever and chikungunya. (http://www.ncbi.nlm.nih.gov/pubmed/23102486)

A 42-Year-Old Man Comes to the Hospital with a 4-Day