title: Frequencies of dhfr/dhps multiple mutations and Plasmodium falciparum submicroscopic gametocyte carriage in Gabonese pregnant women following IPTp-SP implementation.
abstract: This study analyzed the relationship between intermittent preventive treatment with sulfadoxine-pyrimethamine (SP) (IPTp-SP), the rate of multiple resistant parasites and of submicroscopic gametocyte carriage among pregnant women at the beginning of IPTp implementation in Gabon (2005) and six years after (2011). The detection of pfdhfr and pfdhps gene mutations was performed by PCR-RFLP in Plasmodium (P.) falciparum positive samples collected from pregnant women in 2005 and 2011. Gametocytes carriage was detected by Pfs25mRNA amplification using QT-NASBA. Data were analyzed according to the time of collection (study period) and IPTp-SP doses. The proportion of isolates with at least a triple Pfdhfr mutation (n = 39/42, 92.9% versus 100%, n = 78/78)) and of those isolates with the S108N/C59R/N51I/S436A/A437G multiple mutation (17.9% versus 75.6%) significantly increased between 2005 and 2011 (p<0.01). Mutations I164L and A581G were not found, while higher proportions of 436 and 437 mutations were detected in 2011.A trend toward a higher frequency of isolates with five mutations was observed in women who received two SP doses (p<0.01). Pfs25mRNA was found in 6.8 % (n = 3/44) and 34.6% (n = 27/78) of the samples collected in 2005 and 2011 respectively (p<0.01). In 2011, 74.0% (n = 20/27) of women with detected submicroscopic gametocytes carried parasites with the S108N/C59R/N51/S436A/A437G multiple mutation. All the ten delivering women who received three IPTp-SP doses had a submicroscopic Plasmodium falciparum infection, but none had detected gametocytes. Following IPTp-SP implementation, an increase in the frequency of multiple mutant parasites and of submicroscopic gametocyte carriage was observed among pregnant women living in Gabon.
authors.forename: Marielle K
authors.initials: MK
authors.lastname: Bouyou-Akotet
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Tshibola
authors.forename: Denise P
authors.initials: DP
authors.lastname: Mawili-Mboumba
authors.forename: Julie
authors.initials: J
authors.lastname: Nzong
authors.forename: Noemi
authors.initials: N
authors.lastname: Bahamontes-Rosa
authors.forename: Gladys
authors.initials: G
authors.lastname: Tsoumbou-Bakana
authors.forename: Maryvonne
authors.initials: M
authors.lastname: Kombila
mesh_terms: D000962:Antimalarials / Q000627:therapeutic use; D002353:Carrier State / Q000469:parasitology*; D018890:Chemoprevention / Q000379:methods; D016054:DNA, Protozoan / Q000235:genetics; D004094:Dihydropteroate Synthase / Q000235:genetics*; D004338:Drug Combinations; D005260:Female; D005681:Gabon; D005787:Gene Frequency; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology* / Q000517:prevention & control; D050505:Mutant Proteins / Q000235:genetics*; D009154:Mutation; D010963:Plasmodium falciparum / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000469:parasitology*; D011739:Pyrimethamine / Q000627:therapeutic use; D013413:Sulfadoxine / Q000627:therapeutic use; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D004338:Drug Combinations; D050505:Mutant Proteins; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D013762:Tetrahydrofolate Dehydrogenase; D004094:Dihydropteroate Synthase; D011739:Pyrimethamine