Plasmodium vivax on peripheral smear A college student presents w/ headache, fever, chills. Returned 2 days ago from Brazil: rafting & camping trip for two weeks. Diagnosis? Plasmodium vivax. Diagnostic morphologic features enlarged infected rbc up to 1.5 x normal size amoeboid trophozoite with tenuous pseudopodial processes, schizont with 16 merozoites (P. ovale has 8-10 on average) travel history of the patient Infected RBCs may not present stippling so important to use Giemsa stain at proper pH. Doing so can allow one to observe Schüffner’s dots (stippling), a morphologic feature which is only associated with P. vivax & P. ovale. travel history to Brazil (P. ovale not in New World) Indiana University Infectious Diseases Fellowship @IUIDfellowship #PlasmodiumVivax #pvivax #malaria #peripheral #smear #blood #clinical #pathology
