oa Point Mutation in Chloroquine Resistance-Associated Genes (Pfcrt and Pfmdr-1) in Imported Cases of Malaria in Qatar

Background

Imported malaria has been a great challenge for public health in the State of Qatar due to the large number of immigrant workers come from the Indian subcontinent and Sub-Saharan Africa. Antimalarial drug resistance has emerged as one of the greatest challenges facing malaria control today. Chloroquine (CQ) resistance in Plasmodium falciparum (Pf) is associated with genetic polymorphisms in Pf CQR-transporter (Pfcrt) and Pf multi-drug resistance (Pfmdr-1). Monitoring parasite haplotypes that predict susceptibility to major anti-malarials can guide treatment policies. CQ is used in State of Qatar mainly for treatment of uncomplicated Pf infection and incidence of CQ resistant Pf in Qatar is yet unknown. Thus, present study is conducted to determine the polymorphic regions of CQ drug resistance genes (Pfmdr1-codon86 and Pfcrt-codon76) in imported malaria cases in the State of Qatar.

Method

During September 2013 to September 2015, a total of 325 (79 Pf and 246 P. vivax) microscopically positive uncomplicated malaria samples were collected from Emergency Room, Al-Khor General Hospital and Hamad General Hospital, HMC, Qatar and confirmed by molecular assay. Nested-PCR and Restriction Fragment Length Polymorphism (RFLP) were used to detect alleles of pfcrt gene (K76T) and pfmdr1 gene (N86Y).

Result

Out of 79 uncomplicated malaria cases, the majority of patients were from East and West Africa followed by Indian Sub-continent and Central Africa. Molecular genotyping at codon 86 of the pfmdr1 gene showed that 60.7% harboured wild/susceptible allele (N86), 26.6% mutant/resistant (Y86) and 11.4% had mixed alleles (N86Y). However, the prevalence of Pfcrt mutant allele (T76), wild type (K76) and mixed alleles (T76K) was 72.1%, 22.8% and 5% respectively.

Conclusion

Molecular surveillance strategy based on imported malaria cases can be used to detect and track drug-resistant malaria. The data presented here might be helpful for enrichment of molecular surveillance of antimalarial resistance and will be useful for developing and updating antimalarial guidance for non-immune imported cases in State of Qatar.