Malaria detection by automation : The Manipal experience

Diagnosis of malaria has always been a diagnostic challenge in endemic areas. For many centuries microscopy based diagnosis has been a standard method for routine diagnosis of malaria. And still this is a routine diagnostic method used in low endemic areas which allows species identification. In endemic countries like India microscopy based diagnosis of malaria is still used and despite the presence of expert microscopists, laboratory misdiagnosis of malaria is still a problem. This may be due to immense work load, limited resources and manpower. The aim of the study was to confirm utility of the formula developed by Briggs et al and evaluate the feasibility of rapid diagnosis of malaria by using CBC data and malaria factor derived from standard deviation (SD) values of lymphocyte and monocyte by using haematology counter Beckman Coulter series LH 750 and 755. Three hundred and ten cases and controls were selected from samples sent to clinical lab for evaluation of fever and for routine examination. All cases and controls were scrutinised for malaria factor, thrombocytopenia, monocytosis, mean monocyte volume and pseudoeosinophilia. At cutoff value of 3.4, 97% sensitivity and 89% specificity was obtained. Detection of malaria by automated hematology counters my replace current screening methods for detection of malaria in future, but need of extensive study in different population is need for validation of this method.