Marked differences in the prevalence of chloroquine resistance between urban and rural communities in Burkina Faso.
BACKGROUND
Chloroquine (CQ) resistance has reached high levels in Africa in recent years. Little is known about variations of resistance between urban and rural areas.


OBJECTIVE
To compare the rates of in vivo resistance to CQ and the prevalences of the main molecular marker for CQ resistance among young children from urban and rural areas in Burkina Faso.


METHODS
The current analysis used the frame of a randomized controlled trial (ISRCTN27290841) on the combination CQ-methylene blue (MB) (n=177) compared to CQ alone (n=45) in young children with uncomplicated malaria. We examined clinical and parasitological failure rates as well as the prevalence of the Plasmodium falciparum chloroquine resistance transporter gene (pfcrt) T76 mutation.


RESULTS
Clinical and parasitological failure rates of CQ-MB differed significantly between urban (70%) and rural areas (29%, p<0.0001). Likewise, CQ failure rates were higher in the urban setting. Matching this pattern, pfcrt T76 was more frequently seen among parasite strains from urban areas (81%) when compared to rural ones (64%, p=0.01). In the presence of parasites exhibiting pfcrt T76, the odds of overall clinical failure were increased to 2.6-fold ([1.33, 5.16], p(LR)=0.005). CQ was detected at baseline in 21% and 2% of children from the urban and the rural study area, respectively (p(Chi)=0.002).


CONCLUSIONS
Even within circumscribed geographical areas, CQ efficacy can vary dramatically. The differences in the prevalence of pfcrt T76 and in CQ failure rates are probably explained by a higher drug pressure in the urban area compared to the rural study area. This finding has important implications for national malaria policies.
Meissner
Peter E
PE
Department of Tropical Hygiene and Public Health, Ruprecht-Karls-University, Heidelberg, Germany. peter.meissner@urz.uni-heidelberg.de
Mandi
Germain
G
Mockenhaupt
Frank P
FP
Witte
Steffen
S
Coulibaly
Boubacar
B
Mansmann
Ulrich
U
Frey
Claudia
C
Merkle
Heiko
H
Burhenne
Juergen
J
Walter-Sack
Ingeborg
I
Müller
Olaf
O
D000818:Animals; D002050:Burkina Faso; D002675:Child, Preschool; D002738:Chloroquine / Q000494:pharmacology* / Q000627:therapeutic use; D004351:Drug Resistance / Q000235:genetics*; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000469:parasitology*; D026901:Membrane Transport Proteins / Q000235:genetics; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000302:isolation & purification; D017354:Point Mutation; D015800:Protozoan Proteins / Q000235:genetics; D012424:Rural Population; D016896:Treatment Outcome; D014505:Urban Population
D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; D002738:Chloroquine