OBSERVATIONS ON ONCHOCERCA-VOLVULUS IN EXPERIMENTALLY INFECTED CHIMPANZEES

  • 1 January 1980
    • journal article
    • research article
    • Vol. 31  (1) , 41-54
Abstract
Observations made on 32 chimpanzees experimentally infected with O. volvulus were described. The mean prepatent intervals for the Cameroon forest and the Guatemalan strains of O. volvulus were 13-16 mo. and 12-15 mo., respectively. That for the Cameroon Sudan-savanna strain was much longer, i.e., 22-23 mo. The numbers of microfiliariae found in the skins of animals infected with the Cameroon Sudan-savanna strain were much lower than in animals infected with the other 2 strains. Long-term observations on infected animals showed that microfilarial infections had virtually died out 6.5-9 yr after the last inoculation with infective larvae. Those animals which were inoculated with infective larvae in the head or above the waist tended to show a higher proportion of microfilariae in the upper parts of the body than did those inoculated with infective larvae below the waist. In animals which showed adult worm bundles on only 1 side of the body, the concentration of microfilariae was usually greater on that side of the body. Worm bundles in the chimpanzee varied in size from 8 .times. 5 .times. 2 mm to 4 .times. 3 .times. 2 cm. Out of 47 worm bundles found, only 2 were subcutaneous. The remainder lay deep in the tissues, most commonly adjacent to the posterior surface of the capsule of the hip joint. No onchocerciasis eye lesions were seen in any of the infected animals.