Parasitic procrastination: late-presenting ovale malaria and schistosomiasis

A 29-year-old woman with ovale malaria (most likely contracted, together wi th asymptomatic schistosomiasis, in East Africa two years previously) had f ever, nausea and confusion, jaundice, anaemia, thrombocytopenia, hyponatrae mia and hypokalaemia. She was initially diagnosed with and treated for bloo d-smear-positive vivax malaria. Because of the unusual clinical presentatio n, blood was analysed by a malaria species-specific nested polymerase chain reaction (PCR) assay which identified Plasmodium ovale as the only infecti ng species. This case illustrates (i) that a detailed travel history remain s a vital part of clinical assessment, (ii) ovale malaria can have an excep tionally long incubation period and features of a moderately severe acute i nfection, and (iii) PCR assay may prove a valuable adjunct to blood film ex amination in the diagnosis and speciation of malaria.