Chloroquine-resistant malaria in Burma.

Two field trials to detect chloroquine-resistant malaria were conducted according to WHO recommendations in a malaria free area near Rangoon. Peripheral blood smears were examined for asexual forms of P. falciparum on day one through to day seven, on day 14, 21, and 28 after a standard dose of 1500 mg. of chloroquine base. Haskins test to detect chloroquine in urine was done on all cases and plasma chloroquine levels were measured in some. Out of 105 patients tested RI resistance was detected in 66, RII in 19 and RIII in three. Subsequent trials with other anti-malarial drugs indicated that the chloroquine-resistant P. falciparum were also resistant to one day therapy with pyrimethamine 50 mg. or sulphamethoxypyridazine 1 G given singly; and resistant to one day therapy with combinations of pyrimethamine 50 mg. plus sulphamethoxy pyridazine 1 G, pyrimethamine 13 mg. plus dapsone 100 mg., and trimethoprim 320 mg. plus sulphamethoxazole 1600 mg. All those tested were sensitive to quinine sulphate, 0-6 G given three times a day for 10 days, and were also sensitive to one day therapy with combinations of trimethoprim 500 mg. plus sulphalene 1 G, and pyrimethamine 50 mg. plus sulphamethoxine 1 G. Pyrimethamine 12-5 mg. plus dapsone 100 mg. in weekly doses was shown to be an effective chemoprophylaxis. Quinine was tested on 38 subjects while other drug schedule were tested on six to eight subjects.