A high malaria reinfection rate in children and young adults living under a low entomological inoculation rate in a periurban area of Bamako, Mali.
In areas of intense malaria parasite transmission, preliminary studies of the rate of reinfection after curative therapy suggest that small sample size studies of vaccine efficacy are feasible. However, the effect of transmission rate, which may vary considerably between transmission seasons, on reinfection rate has not been assessed in areas of mesoendemicity with seasonal transmission. To address this question, the Plasmodium falciparum reinfection rate after curative therapy was measured in Sotuba, a Malian village with historically low transmission rates, as estimated by the entomological inoculation rate (EIR). The reinfection rate after curative Fansidar (sulfadoxine-pyrimethamine) treatment was 80.7% (88/109). The EIR during the 13-week study period (seasonal transmission) varied between 1 and 4.5 infected bites/person/month. The finding that reinfection rates were high despite low EIRs suggests that a low EIR may be sufficient to support small sample size vaccine efficacy trials in mesoendemic areas.
Malaria Research and Training Center, Departement d'Epidemiologie des Affections Parasitaires, Faculté de Médicine, de Pharmacie et d'Odonto-Stomatologie, Université du Mali, Bamako.
Issaka
I
Sagara
Djibril
D
Sangaré
Guimogo
G
Dolo
Aldiouma
A
Guindo
Mamady
M
Sissoko
Moussa
M
Sogoba
Mohamed B
MB
Niambélé
Daniel
D
Yalcoué
David C
DC
Kaslow
Alassane
A
Dicko
Amy D
AD
Klion
Dapa
D
Diallo
Louis H
LH
Miller
Yeya
Y
Touré
Ogobara
O
Doumbo
D000293:Adolescent; D000818:Animals; D000852:Anopheles / Q000469:parasitology; D000962:Antimalarials / Q000627:therapeutic use; D002648:Child; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007299:Insect Bites and Stings; D007303:Insect Vectors / Q000469:parasitology; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission*; D008297:Male; D008302:Mali / Q000453:epidemiology; D018512:Parasitemia / Q000188:drug therapy / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission; D010963:Plasmodium falciparum / Q000302:isolation & purification; D011739:Pyrimethamine; D012621:Seasons; D013413:Sulfadoxine
D000962:Antimalarials; D004338:Drug Combinations; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D011739:Pyrimethamine