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. 1968;39(2):137–146.

The effects of drugs on Onchocerca volvulus

1. Methods of assessment, population dynamics of the parasite and the effects of diethylcarbamazine

B O L Duke
PMCID: PMC2554552  PMID: 4881066

Abstract

It is important to standardize quantitative methods for assessing the action of drugs on Onchocerca volvulus in man. There are certain disadvantages to making observations on adult worms removed from excised nodules in treated patients, but a great deal of information on drug action can be obtained by making a careful study of the concentrations of microfilariae in multiple weighed skin snips taken before treatment and at intervals after treatment.

Before drug trials can be carried out intelligently by this method it is necessary to know the normal length of life of the various stages of the parasite in man. By a variety of experimental methods the life-spans of the adult worms and the microfilariae have been determined, as well as the duration of the prepatent interval.

Diethylcarbamazine can be used at doses that are effectively microfilaricidal but have no action on the adult worms. This drug can therefore be used to eliminate any residual microfilariae that remain after treatment with a new drug under trial, thus permitting a more rapid assessment of the latter's action on adult worms.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. CHARTERS J. C. Onchocerciasis; incubation period, clinical course, and treatment at first hand. West Afr Med J. 1955 Sep;4(3):130–135. [PubMed] [Google Scholar]
  2. DUKE B. O. The reappearance, rate of increase and distribution of the microfilariae of Onchocerca volvulus following treatment with diethylcarbamazine. Trans R Soc Trop Med Hyg. 1957 Jan;51(1):37–44. doi: 10.1016/0035-9203(57)90004-4. [DOI] [PubMed] [Google Scholar]
  3. Duke B. O., Lewis D. J., Moore P. J. Onchocerca-Simulium complexes. I. Transmission of forest and Sudan-savanna strains of Onchocerca volvulus, from Cameroon, by Simulium damnosum from various West African bioclimatic zones. Ann Trop Med Parasitol. 1966 Sep;60(3):318–326. [PubMed] [Google Scholar]
  4. Duke B. O., Moore P. J. The contributions of different age groups to the transmission of Onchocerciasis in a Cameroon forest village. Trans R Soc Trop Med Hyg. 1968;62(1):22–28. doi: 10.1016/0035-9203(68)90026-6. [DOI] [PubMed] [Google Scholar]
  5. Duke B. O., Scheffel P. D., Guyon J., Moore P. J. The concentration of Onchocerca volvulus microfilariae in skin snips taken over twenty-four hours. Ann Trop Med Parasitol. 1967 Jun;61(2):206–219. doi: 10.1080/00034983.1967.11686480. [DOI] [PubMed] [Google Scholar]
  6. KERSHAW W. E., DUKE B. O., BUDDEN F. H. Distribution of microfilariae of O. volvulus in the skin; its relation to the skin changes and to eye lesions and blindness. Br Med J. 1954 Sep 25;2(4890):724–729. doi: 10.1136/bmj.2.4890.724. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. WOODRUFF A. W., BARNLEY G. R., HOLLAND J. T., JONES D. E., McCRAE A. W., McLAREN D. S. Onchocerciasis and the eye in western Uganda. Trans R Soc Trop Med Hyg. 1963 Jan;57:50–63. doi: 10.1016/0035-9203(63)90012-9. [DOI] [PubMed] [Google Scholar]
  8. Woodruff A. W., Choyce D. P., Pringle G., Laing A. B., Hills M., Wegesa P. Onchocerciasis in the Usambara mountains, Tanzania: the disease, its epidemiology and its relationship to ocular complications. Trans R Soc Trop Med Hyg. 1966;60(6):695–706. doi: 10.1016/0035-9203(66)90219-7. [DOI] [PubMed] [Google Scholar]

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