INVESTIGATIONS ON FEMALE ONCHOCERCA-VOLVULUS FOR THE EVALUATION OF DRUG TRIALS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 31  (1) , 34-40
Abstract
Females of O. volvulus show several typical morphological alterations during their ontogenesis. In order not to attribute such natural findings to the efficacy of drugs in drug trials female worms isolated from untreated patients in Liberia and Togo were examined by light microscopy. Local incrustations could be found regularly on the surface of the female parasite. Different inclusions are described which could often be found. They partially lead to degeneration and calcification. For the evaluation of ovocidal or embryocidal efficacy of drugs the developmental stages of 290 untreated female worms were quantitatively assessed, normal and pathologically altered forms were distinguished. Embryos were obviously not produced continuously but in intervals of unknown length and frequency. Two thirds of the females contained embryos and microfilariae, 1/3 showed eggs only or had empty uteri. The number of the developmental stages/female varied considerably. On the average more than 200,000 stages/female were found.