Identification and Characterization of Molecular and Biologic Markers of Chloroquine Resistance in Plasmodium Falciparum

Abstract

Malaria is a disease of public health concern, responsible in the rise in malaria-associated morbidity and mortality most especially among children under the age of 5years, pregnant women, and immune-compromised patients. The greatest burden of this disease to mankind has been attributed to Plasmodium falciparum species. The widespread of drug resistant Plasmodium falciparum led to the replacement of chloroquine (CQ) drug in 2006 with Artemisinin Based Combination therapy (ACT) as a first-line treatment for uncomplicated malaria disease in Nigeria. The present study determined the prevalence of P. falciparum in various Age groups, Gender and location as well as the molecular markers of P. falciparum chloroquine transporter gene (Pfcrt) and P. falciparum multidrug resistant gene -1 (Pfmdr-1). Approximately 5% Giemsa stained thick and thin blood films from patient’s blood samples were examined using light microscopy; the presence of P. falciparum parasite was confirmed using Rapid Diagnostic Test kits (Carestart Pf Kit). The prevalence of malaria in the total population studied was 72%. However majority of the infection occurred among the female participants, with a higher prevalence of 41%. In relation to age, individuals within the age bracket 11-20 years also recorded the highest prevalence rate of 10.25% compared with the various age ranges studied. Available results indicated that Giemsa staining technique, more efficiently identified higher number of Plasmodium falciparum than the Rapid Diagnostic Test (RDT): 43.20% and 37.9% by Giemsa stain in both Nsukka and Minna respectively; while the Rapid Diagnostic Test (RDT) identified 38.20% and 35.9% in the same locations. In relation to the demography of participants, prevalence of malaria was higher among those with Secondary educational level in Nsukka (34.66%) while those with No formal education in Minna had prevalence of 30.98% (P<0.05). Majority of the infected individuals were Artisans and students with prevalence of 30.17% among Artisans in Minna and 38.25% among Students in Nsukka (P<0.05). Prevalence of P. falciparum multidrug resistant gene 1 (Pfmdr1) mutations in both Nsukka and Minna was observed to be 4% and 0% respectively; Pfmdr1 gene was dominant in Nsukka. Similarly, P. falciparum chloroquine resistant transporter gene (Pfcrt) had prevalent rate of 8% and 4% in both Nsukka and Minna respectively: preponderance of Pfcrt was thus observed in Nsukka.