title: High prevalence of molecular markers for resistance to chloroquine and pyrimethamine in Plasmodium falciparum from Zimbabwe.
abstract: Chloroquine has been the first line drug of treatment for malaria in Zimbabwe until a recent adoption of an interim policy to treat using a combination of chloroquine (CQ) and sulfadoxine/pyrimethamine (SP). We examined the prevalence of parasites with mutations associated with resistance to the drug combination in three areas that have been previously described to differ in malaria endemicity. Our results show that the parasite population from the three areas had a high prevalence of molecular markers of resistance to chloroquine and pyrimethamine. The prevalence of crt (K76T) was 64, 82, and 92% for Chiredzi, Kariba, and Bindura, respectively. On the dhfr locus, the presence of triple mutations (codons 51, 59, and 108) was approximately 50% for all the three locations. On the other hand, the prevalence of dhps mutations (codons 436, 437, and 540) was low accounting for less than 20% in all the areas. Studies reported here demonstrate widespread prevalence of molecular markers associated with chloroquine and pyrimethamine resistance and should be taken into consideration for further refinement of malaria control strategies in Zimbabwe. The design and implementation of successful control strategies would benefit from understanding the prevalence of mutations associated with drug resistance in parasite populations.
authors.affiliation: Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA.
authors.forename: Godfree
authors.initials: G
authors.lastname: Mlambo
authors.forename: David
authors.initials: D
authors.lastname: Sullivan
authors.forename: Susan L
authors.initials: SL
authors.lastname: Mutambu
authors.forename: White
authors.initials: W
authors.lastname: Soko
authors.forename: Joel
authors.initials: J
authors.lastname: Mbedzi
authors.forename: James
authors.initials: J
authors.lastname: Chivenga
authors.forename: Armin
authors.initials: A
authors.lastname: Gemperli
authors.forename: Nirbhay
authors.initials: N
authors.lastname: Kumar
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology*; D016054:DNA, Protozoan / Q000032:analysis / Q000302:isolation & purification; D004338:Drug Combinations; D004351:Drug Resistance / Q000235:genetics*; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000209:etiology / Q000469:parasitology; D009154:Mutation; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics; D015995:Prevalence; D015800:Protozoan Proteins / Q000235:genetics*; D011739:Pyrimethamine / Q000494:pharmacology*; D013413:Sulfadoxine / Q000494:pharmacology*; D015030:Zimbabwe / Q000453:epidemiology
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D004338:Drug Combinations; D015800:Protozoan Proteins; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D002738:Chloroquine; D011739:Pyrimethamine