Declining efficacies of chloroquine and sulfadoxine-pyrimethamine combination against Plasmodium falciparum on the North Central Plateau, Nigeria: parasitological performance of the drugs

The sensitivity of Plasmodium falciparum to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) combination was assessed in vivo in children under five years of age in Barkin Ladi, in the cool Plateau of North Central Nigeria using the standard 14-day protocol. This was the first study of its kind, in this part of the country, under the new roll-back-malaria (RBM) initiative of the World Health Organization (WHO) Plasmodium infection was detected in 42% of the children screened: pure P. falciparum, 97% pure P. malariae, 2 mixed P. falciparum and P. malariae, 1%. The computed parasite density index (PDI) was 7.42. Children who qualified for enrolment into the study (54 for CQ and 55 for SP) were on average 31.1+14.7 and 26.5 + 14.9 months old, weighing 12.1+2.9 and 10.8+3.6 kg, respectively. Average drug consumptions were 304.0+72.3 mg for CQ and 0.6+0.2 tablet for SP. Cure rates were only 43% and 85%, while mean parasite clearance times (MPCTs) were 5.07 and 3.37 days, respectively confirming a significant decline in sensitivity of P.falciparum to the drugs. The need for an effective first-line drug as well as for combining SP with an effective anti-malaria drug is strongly emphasized