Exflagellated Microgametes of Plasmodium vivax in Human Peripheral Blood: An Unusual Finding in Malaria

Abstract

Among the various diagnostic tests for the detection of malarial parasites, peripheral blood smear examination is the most common test performed for species identification by assessing the morphology of various developmental stages. The stages usually seen on the peripheral blood smear of a patient with Plasmodium vivax infection include schizonts, trophozoite forms and gametocytes. In the lifecycle of malarial parasites, exflagellation of microgametes usually occurs within the mosquito and is an extremely rare finding in human blood. Here, the author report a case of a 24-year-old female patient, who presented with Plasmodium vivax infection and exflagellated microgametes in the peripheral blood smear. To date, there have been only three cases reported from India that demonstrated similar findings. Due to it's rarity, it is crucial to be aware of such unusual exflagellated forms in the context of diagnostics to differentiate between malaria and coinfection with haemoparasites such as spirochetes and trypanosomes.

Keywords

• blood ph
• exflagellation factor
• haemoparasites
• haemozoin