Early appearance of variant parasites in Plasmodium chabaudi infections

Previous studies have shown that the recrudescence parasitaemias seen in mice infected with Plasmodium chabaudi AS strain are antigenically different from the infecting parent population. Antigenic differences between recrudescent and parent populations were demonstrated in a passive transfer assay. In the present study, using the same assay system, it has been shown that in some mice, variant parasites (i.e. different from the parent population) can be detected at a time when the primary parasitaemia is still patent but in remission. This is the first report in Plasmodium of variant parasites being detected during the course of a patent primary parasitaemic episode of an infection initiated with a cloned line.