Short report: Field evaluation of posttreatment sensitivity for monitoring parasite clearance of Plasmodium falciparum malaria by use of the Determine Malaria pf test in central India.

The posttreatment performance of the Plasmodium falciparum histidine-rich protein rapid diagnostic test Determine Malaria pf (Abbott Laboratories, Tokyo, Japan) was assessed in 70 patients in central India with uncomplicated falciparum malaria who were treated with chloroquine, sulfadoxine-pyrimethamine, and arteether. Data were compared with those of microscopy. Results revealed that the sensitivity for predicting recrudescence by means of the Determine test after treatment with chloroquine on Day 14 was 75%, with 50% specificity. However, antigenemia was detected in 16% of patients as late as Day 21 in sulfadoxine-pyrimethamine-treated subjects with a drug-sensitive response. Clearance of parasitemia in thick blood smear and clearance of antigenemia appeared to parallel each other only in arteether-treated subjects. The observed diagnostic trends therefore mean that the potential of the Determine test to detect recrudescent infection is limited.