Insecticide-treated bed nets reduce plasma antibody levels and limit the repertoire of antibodies to Plasmodium falciparum variant surface antigens

The use of insecticide-treated bed nets (ITN) has been documented to reduce malaria morbidity and mortality in areas with endemic malaria, but concern s have been raised that ITN usage could affect the acquisition of malaria i mmunity. Several lines of evidence have indicated that antibodies against v ariant surface antigens (VSA) are important in the development of naturally acquired immunity to Plasmodium falciparum malaria and may thus be good in dicators of immune status. We have compared the levels of VSA antibodies in plasma from children who have used ITN for 4 years to levels in plasma fro m children from a nearby village not using ITN. A total of 97 plasma sample s were analyzed using 13 different P. falciparum isolates. We found that th e children using ITN had significantly lower VSA antibody levels and recogn ized a smaller proportion of the VSA expressed,by the tested parasite isola tes than children not using ITN.