Prevalence of Mutant Alleles Responsible for Chloroquine Resistance among Plasmodium falciparum Isolates in North Central, Nigeria

Background: Although chloroquine (CQ) has been officially replaced with artemisinin combination therapy (ACT) as first line drug for the treatment of malaria in Nigeria since 2005, a lot of people still believe that chloroquine is more effective chiefly because of the decline in the sensitivity of Plasmodium falciparum to ACT. Thus resulting into unofficial use of CQ for self medication. This study was conducted in order to survey the current status of chloroquine resistant strains of pfcrt and pfmdr1 in view of possible re-introduction of chloroquine for malaria treatment.

Methods: DNA was extracted from one hundred (100) microscopically confirmed Plasmodium falciparum positive blood samples spotted on 3 mm Whatman filter paper. The detection of mutations in Plasmodium falciparum chloroquine resistance transporter (Pfcrt) and Plasmodium falciparum multidrug resistance (Pfmdr1) genes was performed by nested polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP).

Results: Results showed the presence of mutant alleles of Pfcrt and Pfmdr1 in 60% and 41% of the samples respectively. However, there was no significant correlation in the prevalence of mutant alleles (T76/Y86) in relation to gender (p = 0.59/ 0.08) and age (p=0.59/0.93) of participants respectively.

Conclusion: The observed high prevalence of chloroquine resistance despite thirteen years of withdrawal calls for serious concern.