ABSTRACT
A controlled randomized trial of anti-helminthic treatment was undertaken in 1996-1997 in a rural area of Madagascar where populations were simultaneously infected with Ascaris lumbricoides, Plasmodium falciparum, and Schistosoma mansoni. Levamisole was administered bimonthly to 107 subjects, whereas 105 were controls. Levamisole was highly effective in reducing Ascaris egg loads in the treated group (P < 10(-3) at all visits), whereas it had no effect on schistosomiasis. Subjects 5-14 years of age, treated with levamisole, had a significant increase of their P. falciparum densities compared with controls (P = 0.003). There was no effect of the treatment on children 6 months to 4 years of age, nor on adults > 15 years of age. This study confirms the results of a randomized trial, which showed a negative interaction in those > 5 years of age between Ascaris and malaria parasite density in another Malagasy population, submitted to a higher malaria transmission.
Subject(s)
Ascariasis/complications , Ascaris lumbricoides/physiology , Malaria, Falciparum/complications , Plasmodium falciparum/physiology , Adolescent , Age Factors , Animals , Anthelmintics/pharmacology , Anthelmintics/therapeutic use , Ascariasis/drug therapy , Ascaris lumbricoides/drug effects , Child , Child, Preschool , Female , Humans , Infant , Levamisole/pharmacology , Levamisole/therapeutic use , Madagascar , Malaria, Falciparum/drug therapy , Male , Parasite Egg Count , Plasmodium falciparum/drug effects , Schistosoma mansoni/drug effects , Schistosomiasis/complications , Schistosomiasis/drug therapy , Seasons , Time FactorsABSTRACT
A controlled randomized trial of antihelminthic treatment was undertaken in 1996-1997 in a rural area of Madagascar where populations were simultaneously infected with Ascaris lumbricoides and Plasmodium falciparum. Levamisole was administered bimonthly to 164 subjects, randomized on a family basis, whereas 186 were controls. While levamisole proved to be highly effective in reducing Ascaris egg loads in the treated group (P < 10(-3) at all bimonthly visits), subjects more than 5 years of age, treated with levamisole had a significant increase in their P. falciparum densities compared with controls (P = 0.02), whereas there was no effect of anti-helminthic treatment on children 6 months to 4 years of age. The demonstration of a clear negative interaction between Ascaris infection and malaria parasite density has important implications. Single community therapy programs to deliver treatments against several parasitic infections could avoid an increase of malaria attacks after mass treatment of ascariasis.
