Prevalence of in vitro resistance to eleven standard or new antimalarial drugs among Plasmodium falciparum isolates from Pointe-Noire, Republic of the Congo.
We determined the level of in vitro resistance of Plasmodium falciparum parasites to standard antimalarial drugs, such as chloroquine, quinine, amodiaquine, halofantrine, mefloquine, cycloguanil, and pyrimethamine, and to new compounds, such as dihydroartemisinin, doxycycline, atovaquone, and lumefantrine. The in vitro resistance to chloroquine reached 75.5%. Twenty-eight percent of the isolates were intermediate or had reduced susceptibility to quinine. Seventy-six percent and 96% of the tested isolates showed in vitro resistance or intermediate susceptibilities to cycloguanil and pyrimethamine, respectively. Only 2% of the parasites demonstrated in vitro resistance to monodesethylamodiaquine. No resistance was shown with halofantrine, lumefantrine, dihydroartemisinin, or atovaquone. Halofantrine, mefloquine, and lumefantrine demonstrated high correlation. No cross-resistance was identified between responses to monodesethyl-amodiaquine, dihydroartemisinin, atovaquone, and cycloguanil. Since the level of chloroquine resistance in vitro exceed an unacceptable upper limit, high rates of in vitro resistance to pyrimethamine and cycloguanil and diminution of the susceptibility to quinine, antimalarial drugs used in combination, such as amodiaquine, artemisinin derivatives, mefloquine, lumefantrine, or atovaquone, seem to be appropriate alternatives for the first line of treatment of acute, uncomplicated P. falciparum malaria.
Pradines
Bruno
B
IMTSSA, URBEP, Bd. C. Livon, Parc le Pharo, BP 46, 13998 Marseille Armées, France. bruno.pradines@free.fr
Hovette
Philippe
P
Fusai
Thierry
T
Atanda
Henri Léonard
HL
Baret
Eric
E
Cheval
Philippe
P
Mosnier
Joel
J
Callec
Alain
A
Cren
Julien
J
Amalvict
Rémy
R
Gardair
Jean Pierre
JP
Rogier
Christophe
C
D000293:Adolescent; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D003223:Congo; D004351:Drug Resistance; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000469:parasitology; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000302:isolation & purification; D013223:Statistics as Topic
D000962:Antimalarials