Plasmodium vivax polymorphism in a clinical drug trial.
Data from a double-blind randomized clinical drug trial were analyzed to find the comparative responses of two antirelapse drugs, bulaquine and primaquine, against different relapsing forms of Plasmodium vivax infection. A 1-year follow-up study strongly suggests that the duration of preerythrocytic development of P. vivax is a polymorphic characteristic, exhibited by two strains of hypnozoites responsible for early and late manifestations after primary infection. Short-term relapses were significantly higher in the first half year than long-term relapses, and the reverse was true in the second half year. Clinical drug response data showed that the hypnozoites characterized for short-term relapse were not susceptible to either of the antirelapse drugs in the currently administered dose, whereas hypnozoites characterized for long incubation were significantly susceptible.
Adak
T
T
Malaria Research Centre (ICMR), 2 Nanak Enclave (Radio Colony), Delhi-110 009, India. adak@vsnl.com
Valecha
N
N
Sharma
V P
VP
D000284:Administration, Oral; D000818:Animals; D000962:Antimalarials / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004351:Drug Resistance / Q000235:genetics; D005500:Follow-Up Studies; D014644:Genetic Variation; D006801:Humans; D016780:Malaria, Vivax / Q000235:genetics / Q000469:parasitology*; D010641:Phenotype; D010966:Plasmodium vivax / Q000187:drug effects* / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D011319:Primaquine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism / Q000627:therapeutic use; D055502:Secondary Prevention
D000962:Antimalarials; D011319:Primaquine; C063469:bulaquine