Children in Burkina Faso who are protected by insecticide-treated materials are able to clear drug-resistant parasites better than unprotected children.
BACKGROUND
It has been suggested that reducing exposure to malaria by vector control might impair the development of naturally acquired immunity to malaria. It is also thought that an individual's ability to clear drug-resistant malarial parasites after treatment is enhanced by acquired immunity.


METHODS
To investigate the hypothesis that insecticide-treated materials may affect the acquisition of immunity to malaria, we compared the ability of children living in villages in which insecticide-treated curtains (ITCs) had been used for 6-8 years to clear resistant parasites after treatment with chloroquine (CQ) with that of children living in unprotected villages.


RESULTS
A total of 1035 children aged 6-59 months with falciparum malaria were treated with CQ; 409 were subsequently identified as carrying parasites with the pfcrt-76T allele. More children from ITC villages cleared parasites harboring this allele than did children from non-ITC villages (34.1% vs. 24.0%; adjusted odds ratio [OR], 1.80 [95% confidence interval {CI}, 1.15-2.80]; P=.01). The difference in the clearance of parasites with the pfcrt-76T allele was seen in children aged 6-35 months (32.3% vs. 19.3%; adjusted OR, 2.34 [95% CI, 1.18-4.66]; P=.02) but not in older children (37.3% vs. 37.0%; adjusted OR, 1.09 [95% CI, 0.56-2.10]; P=.97). Rates of adequate clinical response among children carrying parasites with the pfcrt-76T allele were similar in ITC and non-ITC villages (75.1% vs. 68.6%; adjusted OR, 1.21 [95% CI, 0.61-2.39]; P=.58).


CONCLUSIONS
Our data suggest that the children who were protected from malaria by ITCs acquired functional immunity more rapidly than did the control children.
Diallo
Diadier A
DA
Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso. ddiallo.cnlp@fasonet.bf
Sutherland
Colin
C
Nebie
Issa
I
Konate
Amadou T
AT
Ord
Rosalynn
R
Ilboudo-Sanogo
Edith
E
Greenwood
Brian M
BM
Cousens
Simon N
SN
D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D001512:Bedding and Linens; D002050:Burkina Faso; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D007223:Infant; D007306:Insecticides; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000276:immunology / Q000469:parasitology; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics; D009032:Mosquito Control; D018512:Parasitemia; D010963:Plasmodium falciparum / Q000235:genetics / Q000302:isolation & purification*; D015800:Protozoan Proteins / Q000235:genetics; D012424:Rural Population
D000962:Antimalarials; D007306:Insecticides; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; D002738:Chloroquine