Risk in a national malaria control programme in Mali: underdosage of antimalarials

In order to be able to start malaria control activities based on the systematic treatment of episodes of fever in the context of a primary health care programme in the Sélingué dam area, it was necessary to determine the sensibility of P. falciparum to chloroquine given at 25 mg/kg body weight for 3 days. The WHO 7-day test was adopted and administered to schoolchildren aged 7 to 14 years. Out of a total of 259 children screened, the parasitological examination of the thick blood film revealed the presence of hematozoids in 107 children (i.e. a parasite index of 41.3%). Of the 107,59 had parasitaemia appropriate for the in vivo test, but only 43 could be observed till the end of the 7-day test period. The results of the in vivo study indicated a single case where no elimination of the parasites was observed until day 6. The remaining 42 cases became negative between day 3 and day 4. The mean elimination time for the parasite in our study was 3.6 days. The prolonged parasite clearance rate was explained by the fact that the chloroquine tablets contained only 65% of the declared contents of chloroquine base.