Hetrazan in the treatment of filariasis due to Wuchereria malayi

Abstract

1. (i) Twenty persons with symptomless blood infections of microfilaria malayi, eight with clinical filariasis and no microfilariae, and one with both, have been treated with hetrazan dihydrogen citrate in varying doses and for varying periods. 2. (ii) The patients with blood infections have had more severe reactions, and the patients with clinical filariasis less severe reactions, than those reported by various workers for similar types of W. bancrofti infection. 3. (iii) Hetrazan in doses of 0·28 mg. per kg. t.i.d. and over, quickly cleared microfilaria malayi from the blood of 18 patients, and only five showed recurrences out of 11 re-examined 10 to 13 months afterwards.In two other patients, the minimum effective dose seemed to be between 0·12 and 0·25 mg. per kg. t.i.d. 4. (iv) Treatment had little immediate effect on the condition of eight patients with clinical filariasis and no blood infection. Three were re-examined 9 to 10 months later, and reported a considerable degree of freedom from filarial fever; in two the swelling had decreased, and in one it was unchanged. The biggest immediate improvement was shown by one man who had both clinical filariasis and blood microfilariae, and who had a febrile reaction during treatment; this improvement had been maintained up to 10 months after treatment. 5. (v) The nocturnal periodicity of microfilaria malayi in the peripheral blood was observed in two patients, and the rapidity of action of hetrazan in preventing the normal rise was observed in one of them. 6. (vi) Leucocyte counts during treatment were recorded in three patients, and revealed changes in the two with blood infections which did not occur in the one with clinical filariasis. 7. (vii) After discussion of the contrast in the clinical reactions observed in W. malayi and W. bancrofti infections, it is suggested that a main reason is the difference in species of filaria. 8. (viii) Unsupervised mass treatment with hetrazan is not considered practicable in endemic areas of filariasis due to W. malayi, owing to the marked clinical reactions which would occur in the microfilaria carriers.