Parasitological rebound effect and emergence of pyrimethamine resistance in Plasmodium falciparum after single-dose sulfadoxine-pyrimethamine.

Author(s): Marks F, von Kalckreuth V, Kobbe R, Adjei S, Adjei O, Horstmann RD, Meyer CG, May J

Affiliation(s): Infection Epidemiology Group, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.

Publication date & source: 2005-12-01, J Infect Dis., 192(11):1962-5. Epub 2005 Oct 20.

Publication type: Randomized Controlled Trial

Intermittent preventive treatment for malaria in infants (IPTi) is a promising malaria control strategy. However, mass preventive treatment for malaria inherently bears the risk of increasing drug resistance. Here, the effect of single-dose sulfadoxine-pyrimethamine (S-P) versus placebo on Plasmodium falciparum infection rates was assessed in 63 selected infants who were aparasitemic at enrollment. An increase in the proportion of infants with isolates exhibiting drug resistance-associated mutations was detected 3 weeks after drug application in the treatment group. S-P, in the setting of IPTi, appears to cause a parasitological rebound effect in which there is selection of drug-resistant parasites for a short period after drug clearance.