Plasmodium vivax malaria relapses after primaquine prophylaxis.(LETTERS)

To the Editor: Standard treatment of patients with Plasmodium vivax malaria includes chloroquine, followed by primaquine terminal prophylaxis. Reports of true primaquine failure and subsequent P. vivax relapse are unusual; most suspected cases can be ascribed to poor patient adherence, recrudescence of a chloroquine-resistant strain, or P. vivax reinfection. We report a case of P. vivax malaria relapse after therapy with quinine, doxycycline, and primaquine, and again after treatment with chloroquine and primaquine. P. vivax relapses after primaquine treatment are exceedingly rare…