Malaria and filaria co-infection in a febrile patient

Malaria and filariasis are mosquito-borne diseases caused by protozoal and nematode parasites, respectively. Despite different vectors, they can occur together under suitable conditions in endemic regions. In our case, microfilariae were incidentally discovered during a blood film examination for malaria. Accurate detection of microfilariae, especially in cases of low parasitemia, requires multiple blood smears and consideration of Wuchereria bancrofti's nocturnal periodicity, with blood collection ideally performed at night when parasitemia levels are highest. The presence of eosinophilia in our patient suggested a non-malarial parasitic infection, as eosinophilia is relatively uncommon in acute malaria. Our case highlights the need for a broad differential diagnosis, particularly in regions where both diseases are endemic and emphasise the value of detailed peripheral smear examinations to detect parasitic co-infections. Proper identification is essential for guiding tailored treatments in such complex cases.