COMPARISON OF IMMUNOCHROMATOGRAPHY AND MICROSCOPIC FILM METHOD FOR THE DIAGNOSIS OF MALARIA IN LIBERIA
Objective: To compare immunochromatography and microscopic film method for the diagnosis of malaria in patients reporting to United Nations deployed hospital in Liberia.
Study Design: Diagnostic accuracy study.
Place and Duration of Study: Departments of Pathology and Medicine, United Nations deployed hospital in Liberia, West Africa, from Feb 2015 to Dec 2016.
Methodology: A total of 250 febrile patients of all ages and both genders reporting to United Nations deployed hospital in Liberia, with typical clinical features of malaria and advised for workup of malarial parasite were included. The febrile patients with no typical clinical features of malaria and negative malarial parasite both on immunochromatography and microscopic methods were excluded. Pretreatment whole blood in ethylenediamine tetraacetic acid was collected for testing malarial parasite on immunochromatography and comparing with gold standard microscopic film method. On 4th day of treatment with tablet Artemether + Lumefantrine 40/240 mg in double strength (DS), whole blood in ethylenediamine tetraacetic acid was tested again for malarial parasite on immunochromatography and microscopic film method.
Results: In total of 250 patients, 150 were found negative for malarial parasite both on immunochromatography and film method. Out of 100 cases, found positive for malarial parasite on any of the methods, 75% were males and 25% were females with mean age of 38 + 5 years. The type of malarial parasites found in all positive cases was plasmodium falciparum. Pre-treatment malarial parasite was found positive on microscopic film in 95% cases and on immunochromatography in 88% cases. Mean malarial parasite index was 0.49% ranging from 0 to 3.5%. Post-treatment malarial parasite was found positive on immunochromatography in 88% cases and in 14% cases on malarial parasite film. Post treatment mean malarial parasite index was 0.04% ranging from 0 to 1.8%. Pretreatment malarial parasite immunochromatography sensitivity was 87% and specificity was 97%.
Conclusion: Immunochromatography provides rapid, sensitive, user friendly and practical alternative to slide microscopy for the diagnosis of malaria especially in remote areas, despite the highlighted shortcomings of false-negative and false-positive results.