Molecular evidence for relapse of an imported Plasmodium ovale wallikeri infection

Here, the case of a 16-year-old male, who presented with fevers to the outpatient department in Vienna, Austria, after travelling to Uganda and Papua New Guinea is described. Infection with Plasmodium malariae was diagnosed by microscopy and the patient was treated accordingly with a full course of supervised artemether–lumefantrine. He was discharged in good clinical condition with a negative blood smear. One month after initial diagnosis, he returned complaining of fever. Thick blood smear was positive again for malaria parasites, which were confirmed as P. ovale wallikeri by PCR. Retrospective analysis revealed the identical Plasmodium spp. in the initial blood samples. Molecular analysis of various gene loci (nuclear porbp2, 18S rRNA and potra genes) gave identical results providing further evidence for relapse by an identical parasite genotype. Consecutively, the patient was retreated with artemether–lumefantrine and received a regimen of primaquine according to WHO guidelines.