Genetic Polymorphisms of Pfcrt K76T and Pfmdr1 N86Y among Asymptomatic School Children in Forest Communities of Ekondo Titi Subdivision along the Cameroon-Nigeria Border Area

ABSTRACT

Aims:The study sought to quantifyPlasmodiuminfection and molecular markers for chloroquine resistance among asymptomatic school children.Study Design:The study was cross-sectional.Place and Duration of StudyThe study was carried out in Ekondo Titi Subdivision near Original Research Article Cameroon's south-western border with Nigeria from March to May and from September to October 2014.Methodology:The prevalence of humanPlasmodium specieswas determined by nested PCR (Polymerase Chain Reaction) using DNA from dried blood spot in six primary schools. A PCR/RFLP analysis (Restriction Fragment Length Polymorphism) was used to determine the prevalence of chloroquine resistance (CQR) associatedpfcrt76T andpfmdr1 56Y point mutations in Plasmodiumfalciparumasymptomatic school children.Results: A nested PCR amplifying the 18S small-subunit ribosomal RNA (SSU rRNA) gene of Plasmodiumin 205 samples confirmed 76.1% of the isolates as asymptomatic P.falciparuminfections, with a substantial proportion 22% ofP. malariaeinfection. Among these, 3.6% were singleP. malariaeinfections and 15.1% wereP. falciparumandP. malariaemixed infections. MixedP. falciparumandP. ovaleinfections were2.0%. Of the 156Plasmodium falciparum, positive samples by species-specific PCR, 107 samples withP. falciparummono-infection were analyzed for the presence of drug resistant allelespfcrt76T andpfmdr1-Y 86. The prevalence ofpfcrt76T mutation (74.6%) was higher than that of thepfmdr1-Y86 mutation (25.4%). Logistic regression analysis of socio-demographic factors predicted no significant association betweenpfcrt76T mutation with gender and communities.Conclusions:The results indicated a high prevalence ofP. malariaeand mixed infection in the area under study. The high-level distribution of thepfcrtT76observed in the study could be possibly attributed to the fact that CQ remained widely used at the community level more than 14 years after withdrawal