Exflagellation of microgametocytes in Plasmodium vivax malaria: a diagnostic conundrum.
OBJECTIVE
To present a clinical diagnostic conundrum of unidentified structures in a blood smear from a patient with Plasmodium vivax malaria.


METHODS
A 37-year-old Ethiopian male presented with a 4-month history of chills, chronic diarrhea and weight loss. He was diagnosed with P. vivax malaria, advanced HIV infection and Isospora belli enteritis. Unidentified structures initially confusing to the diagnosticians were seen in blood smears taken on admission. The structures were initially considered to represent atypical spirochetes, but were later identified as microgametes and other exflagellation forms of P. vivax. The patient recovered after receiving adequate treatment for his infections.


CONCLUSIONS
This case illustrates that exflagellation may be observed in blood smears from patients with P. vivax malaria. Size and morphological characteristics differentiate malaria microgametes and other exflagellation forms from microfilaria, spirochetes and trypanosomes.
Department of Medicine, Akershus University Hospital, Nordbyhagen, Norway.
Asle
A
Enger
Øystein Anders
ØA
Strand
Trond
T
Ranheim
Kjell Block
KB
Hellum
D000328:Adult; D000818:Animals; D005407:Flagella / Q000502:physiology*; D005854:Germ Cells / Q000502:physiology*; D006801:Humans; D016780:Malaria, Vivax / Q000175:diagnosis / Q000469:parasitology*; D008297:Male; D010966:Plasmodium vivax / Q000166:cytology* / Q000254:growth & development