TY - JOUR
T1 - Increased density but not prevalence of gametocytes following drug treatment of Plasmodium falciparum
AU - Ali, Eltayeb
AU - Mackinnon, Margaret J.
AU - Abdel-Muhsin, Abdel Muhsin A.
AU - Ahmed, Salah
AU - Walliker, David
AU - Babiker, Hamza A.
N1 - Funding Information:
We would like to thank the inhabitants of Asar for their co-operation and help. We are grateful for the help of the Malaria Research Group of the Biochemistry Department, Faculty of Medicine, Khartoum University, the Malaria Administration of the Sudanese Ministry of Health, and the staff of Gedaref Hospital, Sudan. Financial support was received from the Medical Research Council, UK, the Wellcome Trust, UK, the Gordon Memorial College Trust Fund, UK, the University of Edinburgh, UK, the Royal Society of London, UK, and the International Atomic Energy Agency (IAEA).
PY - 2006/2
Y1 - 2006/2
N2 - We monitored post-treatment Plasmodium falciparum among patients treated with chloroquine (CQ) and sulfadoxine-pyrimethamine (SP; Fansidar®) in a village in eastern Sudan. Parasites were examined on day 0 (pre-treatment), day 7, day 14 and day 21 (post-treatment) during the transmission season. A further sample was taken 2 months later (day 80) at the start of the dry season. Asexual forms and gametocytes were detected by microscopy, and reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect expression of gametocyte-specific proteins pfs25 and pfg377. Gametocyte carriage, as revealed by microscopy, increased significantly following CQ and SP treatment, reaching a maximum between days 7 and 14. When measured by RT-PCR, however, there was no significant difference in gametocyte rate between day 0 and days 7 or 14. RT-PCR gametocyte rates dropped dramatically by day 80 post treatment but were still 33% and 8% in the CQ- and SP-treated group at this time. Alleles associated with drug resistance of P. falciparum to chloroquine (the chloroquine resistance transporter, pfcrt, and multidrug resistance, pfmdr1) and to pyrimethamine (dihydrofolate reductase, dhfr) were seen at a high frequency at the beginning of treatment and increased further through time following both drug treatments. Infections with drug-resistant parasites tended to have higher gametocyte prevalence than drug-sensitive infections.
AB - We monitored post-treatment Plasmodium falciparum among patients treated with chloroquine (CQ) and sulfadoxine-pyrimethamine (SP; Fansidar®) in a village in eastern Sudan. Parasites were examined on day 0 (pre-treatment), day 7, day 14 and day 21 (post-treatment) during the transmission season. A further sample was taken 2 months later (day 80) at the start of the dry season. Asexual forms and gametocytes were detected by microscopy, and reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect expression of gametocyte-specific proteins pfs25 and pfg377. Gametocyte carriage, as revealed by microscopy, increased significantly following CQ and SP treatment, reaching a maximum between days 7 and 14. When measured by RT-PCR, however, there was no significant difference in gametocyte rate between day 0 and days 7 or 14. RT-PCR gametocyte rates dropped dramatically by day 80 post treatment but were still 33% and 8% in the CQ- and SP-treated group at this time. Alleles associated with drug resistance of P. falciparum to chloroquine (the chloroquine resistance transporter, pfcrt, and multidrug resistance, pfmdr1) and to pyrimethamine (dihydrofolate reductase, dhfr) were seen at a high frequency at the beginning of treatment and increased further through time following both drug treatments. Infections with drug-resistant parasites tended to have higher gametocyte prevalence than drug-sensitive infections.
KW - Chloroquine
KW - Drug resistance
KW - Gametocytogenesis
KW - Plasmodium falciparum
KW - RT-PCR
KW - Sudan
KW - Sulfadoxine-pyrimethamine
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U2 - 10.1016/j.trstmh.2005.04.021
DO - 10.1016/j.trstmh.2005.04.021
M3 - Article
C2 - 16257026
AN - SCOPUS:29744451313
SN - 0035-9203
VL - 100
SP - 176
EP - 183
JO - Transactions of the Royal Society of Tropical Medicine and Hygiene
JF - Transactions of the Royal Society of Tropical Medicine and Hygiene
IS - 2
ER -