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Published on: January 14, 2018
The population dynamics of Onchocerca volvulus in the human host
1River Blindness Foundation, Lancaster, United Kingdom.
Tropical Medicine and Parasitology : Official Organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft Fur Technische Zusammenarbeit (GTZ)
|June 1, 1993
Summary
This study quantifies onchocerciasis by linking palpable nodules to female worm burden and microfilariae (mfs) loads. Findings reveal many female worms are impalpable, impacting infection intensity estimates.
Area of Science:
- Parasitology
- Epidemiology
- Tropical Medicine
Background:
- Quantitative aspects of onchocerciasis, including the relationship between female worm burden, microfilariae (mfs) load, and infective larvae (L3) exposure, are understudied.
- Understanding these quantitative relationships is crucial for accurate onchocerciasis assessment and control strategies.
Purpose of the Study:
- To investigate the quantitative relationships between adult female Onchocerca volvulus, microfilariae (mfs) load, and infective larvae (L3) exposure in human hosts.
- To estimate the total numbers of adult female worms and mfs in individuals with varying infection intensities.
Main Methods:
- Estimating productive female worm numbers using palpable nodule counts.
- Estimating total mfs load through skin snip concentrations.
- Utilizing the Annual Transmission Potential to predict L3 development into mature female worms.
Main Results:
- Analysis of West African data indicates a significant proportion of adult female worms are impalpable, located deep within the body.
- The three investigated approaches yield numerically comparable results.
- These findings allow for linked estimates of total adult female worms and mfs burdens across different infection intensities.
Conclusions:
- A substantial portion of the adult female Onchocerca volvulus burden in onchocerciasis patients is not detectable through palpation.
- The study provides a framework for estimating total worm and microfilariae loads, improving the quantitative understanding of onchocerciasis.
- These quantitative insights are essential for refining epidemiological models and control interventions for onchocerciasis.
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