The Detection of Plasmodium vivax DNA, and Antibody using Filter Paper Blood

Han, Tae Hee; Paik, In Ki; Um, Tae Hyun; Cho, Chong Rae; Whang, Dong Hee; Shin, Bo Moon

Abstract

BACKGROUND
Filter paper blood samples are convenient for sampling, storage and transport, and widely used for diagnostic and epidemiological studies of Plasmodium species. Our study was aimed to establish antibody and DNA tests using filter paper and to evaluate the usefulness of filterpaper blood sample and storage duration at room temperature. METHODS: 50 L whole blood of 45 Plamsmodium vivax infected patients were spotted on filter paper, dried, and kept in a drawer at room temperature. The paired, whole blood samples were stored at -70degrees C freezer temperature. The filter paper samples were used for PCR at 12 and 24 months. The standard filter paper samples (5, 000, 500, 100, 50, 5, 1 parasite/microL) were made from 3 patients and used for polymerase chain reaction every 3 months until 2 years, antibody test filter paper samples were used every month for 8 months. As standard, -70 degrees C whole blood samples were used. RESULTS: P. vivax DNA was detected in all (45/45) of the filter paper samples by PCR during 24months of storage. Detection limit of PCR was 1 P. vivax/microL using standard filter paper samples for12 months of storage, and 5 P. vivax/microL samples after that. The P. vivax antibody was detected perfectly(43/43) from filter paper samples during 5 months of storage. After that, the antibody detectionrates were, respectively, 81.4% (35/43), 60.5% (26/43), 51.2% (22/43) at six, seven and eight months. CONCLUSIONS: Filter paper blood samples stored at room temperature remained stable for PCR and antibody studies for 1 year and 5 months, respectively.