Field evaluation of the use of an ELISA to detect chloroquine and its metabolites in blood, urine and breast-milk

Abstract The evaluation of an enzyme-linked immunosorbent assay (ELISA) for chloroquine and its metabolites in blood, urine and breast-milk is reported. ELISA blood levels, following standard treatment with chloroquine of pregnant and non-pregnant women, showed mean values comparable to other analytical methods. Blood chloroquine concentrations were estimated at day 0, 350–400 ng/ml; day 2, 1000–1500 ng/ml; day 14, 350–400 ng/ml; day 28, 180–350 ng/ml. In a separate sample a significant association was observed between history of chloroquine use in the previous 2 weeks and blood ELISA values ( P P = 0·076). This study confirms the low sensitivity ( in vivo tests.