In-vivo and in-vitro sensitivity of Plasmodium falciparum to chloroquine at Indian Oil Corporation, Mathura (U.P.).

In vivo and in vitro susceptibility of Plasmodium falciparum to chloroquine were conducted at Indian Oil Corporation (IOC), Mathura, India. 18 out of 31 cases showed resistance [minimum inhibitory concentration (MIC) 8 pmol] in in vitro study. EC50 and EC90 values estimated from log-probit analysis for resistant isolates were 0.66 and 1.44 microM/litre, and for sensitive isolates 0.28 and 0.96 microM/litre blood respectively. In vivo tests identified 13 cases (40.62%) as resistant and 19 cases (59.73%) as sensitive out of 32 cases. All the cases belonged to IOC, Mathura complex, or its vicinity.