[13-year old girl with fever 6 months after returning from sub-Saharan Africa]

A 13-year-old girl presented with regular fevers, 6 months after a prolonged trip through Africa. The patient reported relapsing fevers at 48 hour intervals. Each febrile episode was followed by pronounced fatigue and a subsequent recovery back to her usual state of health. She reported having taken weekly mefloquine during and after the trip to Africa.

Labortory evaluation revealed a hemoltytic anemia (hemoglobin: 10.8 g / dl, normal range: 12.3-16.0; haptoglobin: < 13 mg / dl, normal range 38-205). An abdominal ultrasound showed a marked splenomegaly (diameter: > 13.1 cm).

A peripheral blood film showed Plasmodium parasites with marked stippling. PCR and sequenicing of the ribosomal RNA gene identified Plasmodium ovale. The patient responded well to oral chloroquine therapy and laboratory parameters normalized within 8 days. After determination of a normal glucose-6-phosphate dehydrogenase activity a 2-week-long therapy with primaquine was initiated (0,3 mg / kg per kg bodyweight of primaquine base daily for 14 days) to eliminate the hyponozoite stage of the parasite.

Currently used prophylacic agents against Malaria (mefloquine, atovaquone / proguanil hydrochloride, doxyxycline) do not prevent chronic liver stage infection (hypnozoite stage) with Plasmodium ovale or Plasmodium vivax. After chemoprophylaxis tertian malaria due Plasmodium vivax or Plasmodium ovale can occur. Therefore, tertian malaria should always be considered in febrile individuals who returned from a trip to the tropics even if chemoprophylaxis was taken.