Pfcrt K76T and Pfmdr 1 Resistance Genes in Post Chloroquine Era in South-South Region of Nigeria

Malaria, a global health problem especially in the sub-Sahara region has been posing a recurrent problem due to the resistance of the parasites to the available antimalarial drugs despite the preventive measures provided by WHO.

Aims: This study is aimed at determining the prevalence of resistance markers in four Niger Delta states of Nigeria, a decade after withdrawal of chloroquine.

Methods: Eight hundred and forty six (846) subjects participated in the study and were distributed as follows, 192(22.7%) Bayelsa; 218(25.8%) Rivers; 196(23.2%) Edo and 240(28.4%) Delta respectively. Malaria parasite identification was carried out using standard parasitological techniques. Genotyping of the resistance markers Pfcrt K76T and Pfmdr 1 was carried out by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP).

Results: Our findings revealed that the prevalence of malaria infection in the four Niger Delta states were 78.1%, 68.8%, 62.8% and 58.8% in Bayelsa, Rivers States, Edo and Delta respectively. There was no statistical difference in the prevalence of malaria within the four Niger Delta states. (P>0.05). Children below the age of 5 years recorded the highest infection rates when compared to subjects in other age groups (P< 0.01). Our findings also revealed that the distribution of mutant Pfcrt K76T and Pfmdr 1 genes across the four states were 12.0% and 28.6%, 4.0% and 22.0%, 14.6% and 29.3%, 10.6% and 25.0% in Bayelsa, Rivers, Edo and Delta state respectively. However, the prevalence of Pfcrt K76T in Rivers State was statistically lower when compared to other states (P < 0.01) while no statistical difference existed in the distribution of Pfmdr 1 mutant genes (P>0.01).

Conclusion: Prevalence of Pfcrt and Pfmdr 1 remained elevated in the Niger Delta states despite the withdrawal of chloroquine over a decade ago. Hence, Nigeria is far from an eventual re-introduction of chloroquine as its resistance markers still persist in our communities. Furthermore, the root cause of the persistence of these resistance markers needs to be investigated.