Molecular Identification of Plasmodium Species in Malaria in Zimbabwe by Mitochondrial DNA Sequencing

Aim: To identify the Plasmodium species circulating in Zimbabwe.

Study Design: Cross-sectional study.

Place of Study: The study was conducted at three malaria referral hospitals in Harare, Zimbabwe from January to May 2016.

Methodology: Blood samples from patients with malaria were collected at three referral hospitals and DNA extracted. Plasmodium mitochondrial genomic DNA was amplified by polymerase chain reaction (PCR) and amplicons were sequenced. The sequences were analyzed using bioinformatics tools and Plasmodium species identified.

Results: A total of 160 blood samples were collected throughout Zimbabwe through three referral hospitals, of which 130 were malaria-positive and 30 were malaria-negative by microscopy. DNA was extracted from 100 samples (80 malaria-positive and 20 malaria-negative) and amplification of Plasmodium mitochondrial DNA was performed. Out of the 100 samples, 78 (78%) showed amplification of the expected PCR band of 220 bp. Of the 80 malaria-positive samples, 77 showed mitochondrial genome amplification and of the 20 malaria-negative samples, 1 showed amplification of the expected band. Out of 78 samples that were successfully amplified, 60 were sequenced. Analysis of the sequences showed that all (100%) the selected samples belonged to Plasmodium falciparum species.

Conclusion: From the analyzed malaria-positive blood samples, P. falciparum was shown to be the only species of Plasmodium present. Further studies with larger sample size may need to be done in order to ascertain whether P. falciparum is the only species causing malaria in Zimbabwe.