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Plasmodium falciparum dhfr but not dhps mutations associated with sulphadoxine‐pyrimethamine treatment failure and gametocyte carriage in northern Ghana
Author(s) -
Mockenhaupt Frank P.,
Teun Bousema J.,
Eggelte Teunis A.,
Schreiber Jonas,
Ehrhardt Stephan,
Wassilew Nasstasja,
Otchwemah Rowland N.,
Sauerwein Robert W.,
Bienzle Ulrich
Publication year - 2005
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/j.1365-3156.2005.01471.x
Subject(s) - dhps , dihydrofolate reductase , dihydropteroate synthase , sulfadoxine , pyrimethamine , biology , gametocyte , plasmodium falciparum , sulfadoxine/pyrimethamine , malaria , virology , genetics , immunology , gene
Summary Both use of sulphadoxine‐pyrimethamine (SP) and SP‐resistance of Plasmodium falciparum are increasing in sub‐Saharan Africa. Mutations in the P. falciparum dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) genes can predict treatment failure of SP, however, the degree of this relationship varies regionally. In northern Ghana, pre‐treatment dhfr/dhps genotypes were examined in 126 children and associations with PCR‐corrected SP treatment outcome and gametocyte carriage were analysed. SP treatment failure within 4 weeks of follow‐up occurred in 28%. Among all pre‐treatment isolates, the dhfr triple mutation (Ile‐51 + Arg‐59 + Asn‐108) was detected in 47%. Compared with dhfr wildtype parasites, the presence of the dhfr triple mutation increased the risk of treatment failure tenfold. Likewise, parasite clearance was delayed in the presence of dhfr variants. Dhfr mutants and dhps Gly‐437 were selected in treatment failure isolates. Gametocytaemia 1 week following treatment was strongly associated with dhfr mutations. Remarkably, this was also true for the prevalence of gametocytes at recruitment. Dhps alleles did neither influence treatment outcome nor gametocyte carriage. In northern Ghana, the prevalence of the dhfr triple mutation can be used as a tool to screen for and to monitor SP resistance. The lack of association between dhps alleles and SP treatment outcome suggests a minor role of these molecular markers in this region at present.