Malaria rapid diagnostic test and Giemsa – stained peripheral blood smear discrepancies in the diagnosis of Plasmodium ovale infection in New England

Abstract

Malaria is a serious mosquito-borne parasitic disease and is one of the most significant causes of death worldwide. In this report we discuss a case of a 26-year-old female healthcare worker who presented to the emergency department with signs and symptoms of persistent fevers, chills, headaches, nausea, and malaise. The patient's history was obtained and several laboratory tests were performed leading to the diagnosis of malaria caused by Plasmodium ovale. The rapid diagnostic test for malaria was negative, and the Giemsa – stained peripheral blood smears were positive for the presence of malarial parasites. Images of the peripheral blood smears were sent to the Centers for Disease Control and Prevention, which confirmed the presence of Plasmodium ovale. We also report 5 other false negative RDTs for P. ovale in our institution in 2016, and the performance of RDTs for all malaria cases during that year. This case demonstrates the importance of obtaining multiple pieces of laboratory data in order to accurately diagnose a patient with malaria, illustrates that evaluation of Giemsa – stained peripheral blood smears is still the gold standard in the laboratory diagnosis of malaria, and emphasizes the importance for clinical laboratory scientists to maintain maximum competency in peripheral blood smear evaluation for bloodborne parasites. ABBREVIATIONS: CBC - Complete blood count, RDT - Rapid Diagnostic Test, RBCs - Red blood cells, CDC - Centers for Disease Control and Prevention, AST - Aspartate Aminotransferase, ALT - Alanine Aminotransferase