Seasonal Carriage ofpfcrtandpfmdr1Alleles in GambianPlasmodium falciparumImply Reduced Fitness of Chloroquine‐Resistant Parasites
| Autor: | Sam Dunyo, Chris Drakeley, Rachel Hallett, Rosalynn Ord, Neal Alexander, Musa Jawara, Geoffrey A. T. Targett, Colin J. Sutherland |
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| Rok vydání: | 2007 |
| Předmět: |
Plasmodium falciparum
Protozoan Proteins Persistence (computer science) Antimalarials Chloroquine parasitic diseases Genotype Odds Ratio medicine Animals Humans Immunology and Allergy Parasite hosting Allele Child Alleles biology Membrane Transport Proteins Drug Resistance Microbial Odds ratio medicine.disease biology.organism_classification Virology Infectious Diseases Gambia Seasons Multidrug Resistance-Associated Proteins Malaria medicine.drug |
| Zdroj: | The Journal of Infectious Diseases. 196:1613-1619 |
| ISSN: | 1537-6613 0022-1899 |
| Popis: | Background. Observations in natural Plasmodium falciparum populations after removal of failing drugs suggest that there is a fitness cost of drug resistance.Methods. To examine the effect of transient removal of drug pressure, we analyzed seasonal changes in the prevalence of chloroquine (CQ)-resistant parasite genotypes in The Gambia. Parasite isolates from 441 children presenting with uncomplicated falciparum malaria over 5 seasons (1998-2002) were linked to weekly rainfall data.Results. The prevalence of CQ-resistant parasites increased slightly over 5 years, with the 76T allele of pfcrt (odds ratio [OR] per year, 1.16; P=.03) and the 86Y allele of pfmdr1 (OR per year, 1.18; P=.02) becoming significantly more common. However, intraseasonal analysis showed that these alleles decreased in prevalence each dry season. Wild-type parasites with respect to both loci predominated as transmission began each year, with resistant parasites becoming more common as drug use increased. This pattern was seen for both pfcrt-76T (OR per week, 1.09; P=.001) and pfmdr1-86Y (OR per week, 1.07; P=.001) and could not be explained by seasonal changes in the clonal complexity of infections.Conclusions. The fitness cost of CQ resistance works against the persistence of resistant parasites through the dry season. |
| Databáze: | OpenAIRE |
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