A traveler presents with fever that recurs in cycles and anemia after visiting malaria-endemic regions. Which parasite is most likely responsible?

• A. Filariasis
• B. Malaria
• C. Trichinella
• D. Cutaneous larval migrans

Answer: (B)

Fever that recurs in cycles after travel to malaria-endemic regions points to malaria caused by Plasmodium species. The repeating fevers come from synchronized rupture of parasitized red blood cells (schizont rupture) and merozoite release, producing fever spikes every 24–72 hours depending on the species. Anemia develops because many red blood cells are destroyed as the parasite multiplies and as the spleen clears infected cells. Transmission by Anopheles mosquitoes seen in these travel histories fits malaria well. Other parasites listed don’t produce this pattern: filariasis causes lymphatic disease and edema; Trichinella typically presents with muscle pain and eosinophilia after pork exposure; cutaneous larval migrans causes serpiginous skin tracks without the characteristic cyclic fever and anemia.