Distribution of Mutations Associated with Antifolate and Chloroquine Resistance among Imported in the State of Qatar.

is the most prevalent parasite worldwide, escalating by spread of drug resistance. Currently, in Qatar, chloroquine (CQ) plus primaquine are recommended for the treatment of malaria. The present study examined the prevalence of mutations in dihydrofolate reductase (), dihydropteroate synthase () genes and CQ resistance transporter () genes, associated with sulphadoxine-pyrimethamine (SP) and chloroquine resistance, among imported cases in Qatar. Blood samples were collected from patients positive for and seeking medical treatment at Hamad General Hospital, Doha, during 2013-2016. The Sanger sequencing method was performed to examine the single nucleotide polymorphisms in , , and genes. Of 314 examined isolates, 247 (78.7%), 294 (93.6%) and 261 (83.1%) were successfully amplified and sequenced for , , and , respectively. Overall, 53.8% ( = 133) carried mutant alleles (58R/117N) in , whereas 77.2% ( = 227) and 90% ( = 235) isolates possessed wild type allele in and genes, respectively. In addition, a total of eleven distinct haplotypes were detected in / genes. Interestingly, K10 insertion in the gene was observed only in patients originating from the Indian subcontinent. The results suggested that CQ remains an acceptable treatment regimen but further clinical data are required to assess the effectiveness of CQ and SP in Qatar to support the current national treatment guidelines. In addition, limited distribution of genetic polymorphisms associated with CQ and SP resistance observed in imported infections, necessitates regular monitoring of drug resistant malaria in Qatar.