Abstract

Significant structural differences are observed between the chloroquine-resistant Vietnam (Smith) strain and the chloroquine-sensitive Malaya (Camp-Sadun) strain of Plasmodium falciparum. The Vietnam strain shows subpellicular microtubules in the gametocyte, granular aggregates of the nucleus and enlargement of food vacuoles in the gametocyte and asexual form, while the Malaya (Camp-Sadun) strain lacks such findings. These differences are attributable to genetic variation rather than to drug resistance.