Title |
The evolution of pyrimethamine resistant dhfr in Plasmodium falciparum of south-eastern Tanzania: comparing selection under SP alone vs SP+artesunate combination
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Published in |
Malaria Journal, October 2011
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DOI | 10.1186/1475-2875-10-317 |
Pubmed ID | |
Authors |
Allen L Malisa, Richard J Pearce, Ben M Mutayoba, Salim Abdullah, Hassan Mshinda, Patrick S Kachur, Peter Bloland, Cally Roper |
Abstract |
Sulphadoxine-pyrimethamine (SP) resistance is now widespread throughout east and southern Africa and artemisinin compounds in combination with synthetic drugs (ACT) are recommended as replacement treatments by the World Health Organization (WHO). As well as high cure rates, ACT has been shown to slow the development of resistance to the partner drug in areas of low to moderate transmission. This study looked for evidence of protection of the partner drug in a high transmission African context. The evaluation was part of large combination therapy pilot implementation programme in Tanzania, the Interdisciplinary Monitoring Programme for Antimalarial Combination Therapy (IMPACT-TZ) METHODS: The growth of resistant dhfr in a parasite population where SP Monotherapy was the first-line treatment was measured for four years (2002-2006), and compared with the development of resistant dhfr in a neighbouring population where SP + artesunate (SP+AS) was used as the first-line treatment during the same interval. The effect of the differing treatment regimes on the emergence of resistance was addressed in three ways. First, by looking at the rate of increase in frequency of pre-existing mutant dhfr alleles under monotherapy and combination therapy. Second, by examining whether de-novo mutant alleles emerged under either treatment. Finally, by measuring diversity at three dhfr flanking microsatellite loci upstream of the dhfr gene. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
United Kingdom | 2 | 4% |
Kenya | 1 | 2% |
Unknown | 54 | 95% |
Demographic breakdown
Readers by professional status | Count | As % |
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Student > Master | 13 | 23% |
Researcher | 12 | 21% |
Student > Ph. D. Student | 8 | 14% |
Student > Doctoral Student | 6 | 11% |
Other | 3 | 5% |
Other | 7 | 12% |
Unknown | 8 | 14% |
Readers by discipline | Count | As % |
---|---|---|
Agricultural and Biological Sciences | 17 | 30% |
Medicine and Dentistry | 12 | 21% |
Biochemistry, Genetics and Molecular Biology | 9 | 16% |
Social Sciences | 3 | 5% |
Computer Science | 2 | 4% |
Other | 5 | 9% |
Unknown | 9 | 16% |