Field Evaluation of an Antigen Detection Immunochromatographic Test for Diagnosis of Plasmodium falciparum Malaria in India

An immunochromatographic test (ICT Malaria P. f.) based on the detection of Plasmodium falciparum HRP-II antigen was evaluated in Gujarat state, India. Whole blood of 148 clinically suspected malaria patients was tested blind by microscopy and ICT simultaneously. Compared with the examination of Giemsa stained thick blood films, ICT test was 99% specific and 92% efficient. It was 100% sensitive for detection of >5000 parasites/μL blood, 90% sensitive (95% CI 72-109) for 1001-5000 parasites/μL, 89% sensitive (CI 69-109) for 501-1000 parasites/μL, 83% sensitive (CI 66-100) for 101-500 parasites/μL and 57% sensitive (CI 31-83) for 22-100 parasites/μL blood. Blood of a patient who had taken some drugs in recent past was negative by film but tested positive on ICT. The test does not require equipment, was easy and rapid (took <8 minutes) to conduct in the field and may be an useful diagnostic and epidemiologic tool in P. falciparum dominant areas.