Detection, identification and semi-quantification of malaria parasites by NASBA amplification of small subunit ribosomal RNA sequences

We have adapted the Nucleic Acid Sequence Based Amplification method (NASBA), a molecular detection method for the amplification of specific RNA sequences, for the detection, identification and semi-quantification of malaria parasites. Primers and probes were selected based on the nucleotide sequence of the small subunit ribosomal RNA gene. NASBA enabled the detection of as little as 0.01 parasitized erythrocytes per mu l blood. When applied to blood samples of patients, NASBA allowed the detection of malaria parasites in confirmed malaria patients. in addition, malaria parasites were detected in a number of patients with a history of suspected malaria. Semi-quantification over a wide parasite range was achieved by analysing serial end-point dilutions of RNA preparations, Semi-quantitative NASBA analysis of malaria parasites in follow-up samples of treated malaria patients showed a rapid decline of parasite levels in most patients and a low level of persistent parasites in some of the patients. (C) 1997 Elsevier Science B.V. All rights reserved.