Chloroquine resistance of Plasmodium falciparum in Bukumbi, Tanzania. An in vivo study.

The sensitivity of Plasmodium falciparum to chloroquine was studied in 42 children in Bukumbi, Tanzania. The standard WHO in vivo test was used, and chloroquine phosphate 25 mg base/kg was administered in divided doses over three days. From the 42 patients 13 (31%) were sensitive to chloroquine and 29 (69%) had not cleared their parasites on day 7. From the resistant cases, 1 showed RI resistance (early recrudescence), 6 showed RII resistance and 18 cases showed RIII resistance. Four were resistant, not further specified. This high degree of resistance might indicate that chloroquine, without control of the intake and uptake, is no longer the drug of choice for this area.