The in vivo sensitivity of Plasmodium falciparum to chloroquine and to sulphadoxine-pyrimethamine combination in Ibadan,Nigeria

Fifty-eight Nigerian children with Plasmodium falciparum malaria were allocated randomly into two groups and treated with either chloroquine (25 mg/kg over three days) or Fansidar (35 mg sulphadoxine (+ $\text{1}\text{20}$ pyrimethamine) per kg single dose)). They were observed for 28 days during which blood films were examined periodically for malaria parasites.Asexual forms of P. falciparum, which were present in the blood films of all the patients in both groups before commencing treatment, disappeared rapidly from the blood so that by the fourth day after starting treatment no parasites were seen in the blood films. The blood films thereafter remained negative in both groups throughout the rest of the 28-day observation period. The rate of fever clearance was also similar in both groups. The study did not show resistance to Fansidar or to chloroquine. There is therefore, at present, no case for the indiscriminate use of Fansidar on the basis of suspected chloroquine resistance.