[Unexpected recurrence of malaria]

Area of Science:

• Tropical medicine
• Infectious diseases
• Parasitology

Background:

• Malaria diagnosis is critical in febrile patients with recent tropical travel.
• Late relapses, recrudescence, or postponed first episodes of malaria can occur long after returning or antimalarial treatment.
• Dormant liver stages (hypnozoites) of Plasmodium vivax and Plasmodium ovale are undetectable in blood but can cause delayed illness.

Purpose of the Study:

• To report a case of mixed Plasmodium infection.
• To illustrate the diagnostic challenges posed by late-emerging Plasmodium ovale malaria.
• To emphasize the importance of considering malaria even after seemingly effective treatment.

Main Methods:

• Clinical case presentation.
• Review of patient history, including travel and treatment.
• Microscopic examination of blood smears (implied).

Main Results:

• A patient presented with a mixed infection of Plasmodium falciparum and Plasmodium ovale.
• Plasmodium ovale was not detected initially due to the absence of its erythrocytic stage.
• Symptoms attributed to Plasmodium ovale emerged weeks after artemisinin-based therapy for the initial infection.

Conclusions:

• Mixed Plasmodium infections can complicate malaria diagnosis and treatment.
• The dormant liver stage of Plasmodium ovale can lead to late clinical manifestations.
• Persistent vigilance for malaria is necessary, even in patients who have received treatment, due to the possibility of late relapses.