The standard adult treatment regimen for Plasmodium vivax malaria is chloroquine (1500 mg over 3 d) plus primaquine (15 or 30 mg daily for 14 d), but patient compliance tends to be poor with the lengthy course. Preliminary observations are reported on the efficacy of a shorter treatment course - artesunate (200mg twice a day for 2 d) plus primaquine (22.5mg base twice a day for 7 d) - given to 28 adult patients infected with P. vivax in Viet Nam. All patients responded quickly to treatment with mean (SD) parasite and fever clearance times of 14.2 (4.0) and 18.6 (8.4) h, respectively. The high dose of primaquine was generally well tolerated, and only one patient (3.6%) had a recurrence of parasitaemia during 28 d of follow-up. As most patients infected with Southeast Asian strains of P. vivax have their first relapse within 28 d after treatment with rapidly eliminated blood schizonticides, the absence of parasitaemia in the remaining 27 patients suggests that this drug regimen was active against both blood and liver stages. Further studies are needed to confirm that this rapidly acting, short artesunate-primaquine regimen can result in better patient compliance and treatment outcomes than the chloroquine-primaquine regimen.

Thiamin deficiency complicates severe Plasmodium falciparum malaria in Thailand and may contribute to acidosis. The authors therefore estimated the frequency of biochemical thiamin deficiency in patients presenting with uncomplicated falciparum malaria in southern Laos. Red cell transketolase activation coefficients (alpha) were measured in 310 patients presenting with uncomplicated falciparum malaria and 42 days after starting treatment. Twelve per cent of patients had biochemical evidence of severe deficiency (alpha values >1.31) at presentation, declining to 3% 42 days later. Thiamin deficiency was common in Lao patients admitted with uncomplicated P. falciparum infection and was reduced following treatment of malaria and multivitamin supplementation. The role of this preventable and treatable disorder in malaria and other acute infections, and the incidence of beriberi in rural Laos, needs further investigation.