A 3-year-old African American boy is brought to the emergency department for fever. Since returning from a family trip to Nigeria last week, he has been lethargic with constant nausea and headache. He has had several episodes of vomiting and watery diarrhea each day and high spiking fevers, chills, and drenching sweats every other day. The boy carries the sickle cell trait and has no other medical problems. He takes no medications and his vaccinations are up to date. His temperature is 40 C (104 F), blood pressure is 90/60 mm Hg, pulse is 132/min, and respirations are 24/min. Examination shows a tired-appearing boy with jaundice. Lungs are clear to auscultation. The abdomen is soft and nontender. Hepatosplenomegaly is present. Range of motion in his neck and extremities is normal. Laboratory studies show mild anemia and thrombocytopenia. Which of the following factors is associated with decreased morbidity from this illness?

Question

A 3-year-old African American boy is brought to the emergency department for fever.  Since returning from a family trip to Nigeria last week, he has been lethargic with constant nausea and headache.  He has had several episodes of vomiting and watery diarrhea each day and high spiking fevers, chills, and drenching sweats every other day.  The boy carries the sickle cell trait and has no other medical problems.  He takes no medications and his vaccinations are up to date.  His temperature is 40 C (104 F), blood pressure is 90/60 mm Hg, pulse is 132/min, and respirations are 24/min.  Examination shows a tired-appearing boy with jaundice.  Lungs are clear to auscultation.  The abdomen is soft and nontender.  Hepatosplenomegaly is present.  Range of motion in his neck and extremities is normal.  Laboratory studies show mild anemia and thrombocytopenia.  Which of the following factors is associated with decreased morbidity from this illness?

Quizplus · Accepted Answer

11ec25c8_d6c2_a57b_bc81_7f1db99afbeb_MD0003_00 This child's clinical presentation is concerning for malaria, a dangerous parasitic infection transmitted by mosquitos in tropical regions worldwide. Almost 2000 people die from malaria every day. Plasmodium falciparum is the primary cause of morbidity and mortality in sub-Saharan Africa. Cyclic fevers (eg, every 2 or 3 days) with other nonspecific systemic symptoms are the key features of malarial illness (Table). The febrile paroxysms parallel the waves of red blood cell invasion when parasites are released from the liver into the bloodstream. Diagnosis is confirmed by microscopic visualization of Giemsa-stained parasites on thick and thin blood smears. tropical regions Carriers of the sickle cell trait are inherently protected from severe disease, as the misshapen red blood cells create a suboptimal environment for parasitic proliferation. Patients with a past history of malarial infection are also at relatively low risk for severe disease on reinfection due to partial immunity. (Choice A) Acute hepatitis A infection can cause fever, abdominal pain, nausea, vomiting, diarrhea, hepatomegaly, and jaundice. However, this patient's cyclic fevers are suggestive of malaria rather than hepatitis. (Choice B) Neisseria meningitides vaccination can prevent infection from serogroups A, C, Y, and W-135. Meningitis causes fever and severe headaches, but patients usually have neck stiffness and photophobia as well. In addition, bacterial meningitis causes precipitous neurologic decline within hours of onset. (Choices C and F) Both sexes are equally susceptible to malaria. However, infants and young children are at increased risk for life-threatening complications, such as cerebral malaria (eg, seizures, delirium, coma). (Choice D) Ciprofloxacin is not recommended for malaria prophylaxis. It can treat traveler's diarrhea caused by Escherichia coli, Campylobacter jejuni, Shigella, and Salmonella. However, bacterial enteritis typically resolves within 5 days and would not cause periodic fevers. Educational objective: Malaria should be suspected in any ill patients, especially those with a history of febrile paroxysms, who have traveled to an endemic-tropical region. Thick and thin blood smears should be ordered for parasite detection and quantification. Nonimmune children are at highest risk of death, but the sickle cell trait confers some protection from severe complications. References: Hemoglobin variants and disease manifestations in severe falciparum malaria. (http://www.ncbi.nlm.nih.gov/pubmed/17519411) Imported pediatric malaria presenting to an urban pediatric emergency department: a case series. (http://www.ncbi.nlm.nih.gov/pubmed/23222110) Does this patient have malaria? (http://www.ncbi.nlm.nih.gov/pubmed/21057136) Hemoglobins S and C interfere with actin remodeling in Plasmodium falciparum-infected erythrocytes. (http://www.ncbi.nlm.nih.gov/pubmed/22075726) Malaria. (http://www.ncbi.nlm.nih.gov/pubmed/23953767)

A 3-Year-Old African American Boy Is Brought to the Emergency