Abstract
Background Successful control programs have impeded local malaria transmission in almost all Gulf Cooperation Council (GCC) countries: Qatar, Bahrain, Kuwait, Oman, the United Arab Emirates (UAE) and Saudi Arabia. Nevertheless, a prodigious influx of imported malaria via migrant workers sustains the threat of local transmission. Here we examine the origin of imported malaria in Qatar, assess genetic diversity and the prevalence of drug resistance genes in importedPlasmodium falciparum,and finally, address the potential for the reintroduction of local transmission. Methods This study examined imported malaria cases reported in Qatar, between 2013 and 2016. We focused onP. falciparuminfections and estimated both total parasite and gametocyte density, using qPCR and qRT-PCR, respectively. We also examined ten neutral microsatellites and four genes associated with drug resistance,Pfmrp1,Pfcrt,Pfmdr1, andPfkelch13,to assess the genetic diversity of importedP. falciparumstrains, and the potential for propagating drug resistance genotypes respectively. Results The majority of imported malaria cases wereP. vivax, whileP. falciparumand mixed species infections (P. falciparum/P. vivax) were less frequent. The primary origin ofP. vivaxinfection was the Indian subcontinent, whileP. falciparumwas mostly presented by African expatriates. ImportedP. falciparumstrains were highly diverse, carrying multiple genotypes, and infections also presented with early- and late-stage gametocytes. We observed a high prevalence of mutations implicated in drug resistance among these strains, including novel SNPs inPfkelch13. Conclusions The influx of genetically diverseP. falciparum,with multiple drug resistance markers and a high capacity for gametocyte production, represents a threat for the reestablishment of drug-resistant malaria into GCC countries. This scenario highlights the impact of mass international migration on the reintroduction of malaria to areas with absent or limited local transmission.