Differential Diagnosis for a 23-year-old man with intermittent chills, fever, and anemia after returning from Africa

• Single most likely diagnosis

  • B. Plasmodium: This is the most likely cause due to the patient's recent travel to Africa, where malaria is prevalent. The symptoms of intermittent chills, fever, and anemia are classic for malaria, which is caused by Plasmodium species.

• Other Likely diagnoses

  • C. Babesia: Babesiosis is a less common but possible diagnosis, especially if the patient has been exposed to ticks in Africa. It presents with similar symptoms to malaria, including fever, chills, and anemia.
  • A. Bartonella: Bartonellosis, caused by Bartonella species, can present with fever, anemia, and other systemic symptoms. However, it is less commonly associated with travel to Africa and the specific symptoms described.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)

  • Severe malaria (Plasmodium falciparum): Even though Plasmodium is already considered the most likely diagnosis, it's crucial to specifically identify and treat severe malaria (caused by Plasmodium falciparum) promptly due to its high mortality rate if left untreated.
  • Tick-borne hemorrhagic fever or other viral hemorrhagic fevers: These are less likely but critical to consider due to their high mortality rates and the patient's travel history. They can present with fever, hemorrhage, and shock.

• Rare diagnoses

  • D. Clostridium: Clostridial infections, such as those causing gas gangrene or Clostridioides difficile infection, are less likely to present with the combination of intermittent chills, fever, and anemia in the context of recent travel to Africa.
  • Other less common parasitic infections: Such as leishmaniasis or trypanosomiasis, which can cause systemic symptoms including fever and anemia but are less likely given the specific symptoms and travel history described.