Relatório preliminar de experiências com o hetrazan, feitas com o fim de verificar sua aplicabilidade no controle da transmissão da Filariose em Belém (Publicado originalmente em 1950)

Abstract

A program is being planned for the control of Filariasis bancrofti in Belém, State of Pará (Brazil), where the disease is known to occur with moderate endemicity. Observations are now under way, on the effect of DDT house spraying against Culex fatigans, the chief vector of Wuchereria bancrofti in Belém. Duo to recent developments in the therapeutics of the disease, it has been decided to include treatment of human carriers of microfilariae, as part of the preliminary studies which are to serve as a basis for the control program. Of the drugs successfully tried by various investigators, hetrazan (1-diethylcarbamyl-4-methylpiperazine hydrochloride) was considered the most suitable for the purpose in view, as previous tests had shown it to be an effective filaricidal, well tolerated in therapeutic doses, and because it could be taken orally. From the Lederle Laboratories, American Cyanamid Co., of New York, U. S. A., one thousand 50mg tablets were received for our experiments. As the time our experiments were begun, the literature on hetrazan was scarce, so we decided to use the drug in a number of well controlled cases, before attempting any large scale treatment, because we wished to acquire personal experience as to its therapeutic efficiency and toxicity. A preliminary report of the results obtained with the first 43 cases treated is here presented. The patients were selected among people found positive in a survey then in progress. Twenty three were males, and 20 females. The ages ranged from 13 to 58 years. All had nocturnal microfilaraemia, but 22 had no past or present symptoms for which the filaria could be held responsible. The other 21 mentioned having suffered in the past, or showed at the time of examination, various symptoms which could be attributable to their Filaria infestation, such as Hydrocele, Varicocele, Orchitis, Epididymitis, Funiculitis, Lymphadenitis, Lymphangitis, Chyluria, Elephantiasis of the lower limbs or the scrotum. No patient was hospitalised for treatment. The dosage used was among the smaller suggested by the Lederle Laboratories because we were primarily interested in the Public Health aspect of the problem, that is, not in curing Filariasis cases, but in determining the minimum dose capable of reducing the microfilaraemia below the transmission level and to keep it there for a long period of time. Two schemes were established for treatment: 1) one daily dose of 1mg per kilogram, for six days; 2) duration of treatment rot predetermined: daily dose of 1mg per kilogram, for as many days as found necessary to negativate 20 cumm of night blood, for 3 consecutive days. Since we had only 50mg tablets, we found it difficult to subdivide them into fractions, so as to obtain total daily doses adequate to the body weight of each patient. Most patients were given 50mg daily, except those weighing much more or much less than 50 kilograms, who received doses roughly in proportion to their weight. Eighteen patients were treated according to the former scheme and 25 according to the latter.