Browsing by Author "Too, Edwin"

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    PublicationOpen Access
    Evidence of partial artemisinin resistance in malaria endemic lake region, Busia county, Western, Kenya
    (Research Square, 2024-07-03) Makau, Mark; Kanoi , Bernard N; Mgawe, Calvin; Maina, Michael; Too, Edwin; Naruse, Taeko; Abkallo, Hussein; Waweru, Harrison; Adung’o , Ferdinand; Kaneko , Osamu; Gitaka, Jesse
    Malaria remains a key health and economic problem particularly in sub-Saharan Africa. The emergence of artemisinin resistance (ART-R) parasite strains poses a serious threat to the control and elimination of this scourge. This is because ART remains the first-line treatment drug in the majority of malariaendemic regions in Sub-Saharan Africa. P. falciparum ART resistance has been linked to mutations in the Kelch – 13 propeller gene (k13) of the Plasmodium falciparum. Single nucleotide polymorphisms in the K-13 region have been associated with delayed parasite clearance in vivo and in vitro. These mutations serve as vital molecular markers for tracking the emergence and dispersion of resistance. Recently, there have been increasing reports of the emergence and spread of P. falciparum ART-R parasites in the Eastern Africa region. This necessitates continued surveillance to best inform mitigation efforts. This study investigated the presence of K-13 mutations in the parasite population in Busia County, Kenya, a known malaria-endemic region. Two hundred twenty-six participants with microscopically confirmed uncomplicated malaria were recruited for this study. They were put under directly observed treatment with Artemether-Lumefantrine (AL), and microscopy repeated after 24 hours. P. falciparum DNA from samples showing the lowest 24-hour relative parasite clearance underwent targeted amplification of the K-13 gene using a semi-nested PCR approach, followed by Sanger sequencing. The recently validated ART-R nonsynonymous mutation C469Y was identified in 3% (n = 3) of the samples suggesting it could have had an impact on clinical parasite clearance 24 hours post-AL administration. Our findings highlight the need for continuous surveillance of AL resistance in western Kenya and the region to determine the spread of ART-R and inform containment.
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    PublicationOpen Access
    PfEMP1 DBLα Sequence Tags in Genomic DNA of P. falciparum Field Isolates from Two Malaria Endemic Sites in Kenya
    (Mount Kenya University, 2015) Makokha, W Francis; Omar, A Sabah; Kimani, T Francis; Magoma, Gabriel; Udu, Rahma; Too, Edwin; Shaviya, Nathan; Hungu, Charity
    Malaria caused by Plasmodium falciparum remains a major cause of childhood morbidity and mortality in sub- Saharan Africa. PfEMP1 protein, coded for by a family of about sixty variant var genes, is a parasite protein found on infected erythrocyte membrane. PfEMP1 protein mediates cytoadherence of infected erythrocytes on endothelial cells which may lead to severe symptoms of malaria. Although PCR amplification of the whole gene is difficult due to high variability, primers targeting the DBLα domain have been designed and used to study pfemp1 genes. This objective of this study was to establish the distribution of DBLα sequence tags in isolates of Plasmodium falciparum from two malaria endemic sites in Kenya.
  • Thumbnail Image
    PublicationOpen Access
    PfEMP1 DBLα Sequence Tags in Genomic DNA of P. falciparum Field Isolates from Two Malaria Endemic Sites in Kenya
    (Mount Kenya University, 2004) Makokha, Francis W; Omar, Saban A; Kimani, Francis T; Magoma, Gabriel; Udu, Rahma; Too, Edwin; Shaviya, Nathan; Hungu, Charity