Prevalence and intensity of Onchocerca volvulus infection and efficacy of ivermectin in endemic communities in Ghana: a two-phase epidemiological study

@article{OseiAtweneboana2007PrevalenceAI,
  title={Prevalence and intensity of Onchocerca volvulus infection and efficacy of ivermectin in endemic communities in Ghana: a two-phase epidemiological study},
  author={Mike Yaw Osei-Atweneboana and J K L Eng and Daniel A. Boakye and John Owusu Gyapong and Roger Prichard},
  journal={The Lancet},
  year={2007},
  volume={369},
  pages={2021-2029}
}
Rates of microfilarial production by Onchocerca volvulus are not cumulatively reduced by multiple ivermectin treatments
TLDR
The data and analyses do not support the hypothesis of a cumulative effect of multiple ivermectin treatments on microfilarial production by female worms and use a Bayesian approach and Markov chain Monte Carlo techniques to fit the model to the data.
Reproductive Status of Onchocerca volvulus after Ivermectin Treatment in an Ivermectin-Naïve and a Frequently Treated Population from Cameroon
TLDR
IVM still had an embryostatic effect on O. volvulus, but the effect was reduced in the frequently treated cohort compared with the control population, which may indicate a reduced sequestration of mf in the worms from the frequentlytreated group.
The impact of ivermectin on onchocerciasis in villages co-endemic for lymphatic filariasis in an area of onchocerciasis recrudescence in Burkina Faso
TLDR
The level of reduction of microfilarial loads suggests that ivermectin is effective against the recrudescent population of O. volvulus in Cascades Region of Burkina Faso.
Phenotypic Evidence of Emerging Ivermectin Resistance in Onchocerca volvulus
TLDR
In some communities adult female worms were non-responsive or resistant to the anti-fecundity effects of multiple treatments with IVM, and a scheme of the varied responses of the adult female worm to multiple treatments is proposed.
THE IMPACT OF IVERMECTIN MASS TREATMENT ON THE PREVALENCE OF ONCHOCERCIASIS BY RAPID EPIDEMIOLOGICAL ASSESSMENT IN GALADIMAWA, KADUNA STATE, NIGERIA
TLDR
The impact of repeated mass treatment with ivermectin on the prevalence of onchocerciasis in Galadimawa, Kaduna State, Nigeria, was assessed and females had insignificant higher prevalences in all the clinical manifestations than males.
Onchocerciasis Transmission in Ghana: Persistence under Different Control Strategies and the Role of the Simuliid Vectors
TLDR
Despite repeated ivermectin treatment, evidence of O. volvulus transmission was documented in all seven villages and above the WHO threshold in two, and Vector species influences transmission through biting and parous rates and vector competence, and should be included in transmission models.
Assessment of the Clinical, Serological and Parasitological Aspects of Onchocercal Skin Disease, 20 Years of Community Directed Treatment with Ivermectin (CDTI) in the Ruvuma, Southwestern Tanzania
  • WH Makunde
  • Medicine
    American Journal of Biomedical Science & Research
  • 2021
TLDR
Assessment of transmission after over 20 years of mass drug administration in the hyper-mesoendemic communities showed clearly that, transmission has not been interrupted in the entire focus, however, in areas considered non endemic in the previous surveys today transmission is ongoing.
Transmission of Onchocerca volvulus continues in Nyagak-Bondo focus of northwestern Uganda after 18 years of a single dose of annual treatment with ivermectin.
TLDR
To determine whether annual ivermectin treatment in the Nyagak-Bondo onchocerciasis focus could safely be withdrawn, baseline skin snip microfilariae and nodule prevalence data from six communities were compared with data collected in the 2011 follow-up.
Status of parasitological indicators and morbidity burden of onchocerciasis after years of successive implementation of mass distribution of ivermectin in selected communities of Yeki and Asosa districts, Ethiopia
TLDR
Biannual CDTi is recommended to continue in Asosa and its surroundings until the infection transmission is fully interrupted, and thorough entomological and serological data need to be generated to ascertain whether complete interruption of parasite transmission has been attained, and for considerations of an evidence-based CDTi cessation.
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References

SHOWING 1-10 OF 32 REFERENCES
An investigation of persistent microfilaridermias despite multiple treatments with ivermectin, in two onchocerciasis-endemic foci in Ghana
TLDR
The results indicate that the significant microfilaridermias that persist despite multiple treatments with ivermectin are mainly attributable to the non-response of the adult female worms and not to inadequate drug exposure or other factors, and justify the routine monitoring of treatment efficacy in any iverMectin-based programme of disease control.
Impact of ivermectin on onchocerciasis transmission: assessing the empirical evidence that repeated ivermectin mass treatments may lead to elimination/eradication in West-Africa
TLDR
Ivermectin treatment has been very successful in eliminating onchocerciasis as a public health problem, however, the results presented in this paper make it almost certain that repeated ivermECTin mass treatment will not lead to the elimination of transmission of onchopocalypse from West Africa.
Clinical and parasitological responses after up to 6.5 years of ivermectin treatment for onchocerciasis
TLDR
Six‐monthly and annual treatment regimens with ivermectin were equally effective in terms of dermatological and parasitological impact, but repopulation data suggest that adult female worms are still alive and fecund, strongly underlining the need to continue treatment.
The chemotherapy of onchocerciasis. XIII. Studies with ivermectin in onchocerciasis patients in northern Ghana, a region with long lasting vector control.
  • K. Awadzi, K. Dadzie, S. Kläger, H. Gilles
  • Medicine
    Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft fur Technische Zusammenarbeit
  • 1989
TLDR
The proportion of dead adult worms was very high in all treatment groups, which is effected by the successful ten years lasting vector control in northern Ghana, and an impact of the treatment with ivermectin on the reproductivity of the parasite could be shown.
The chemotherapy of onchocerciasis X. An assessment of four single dose treatment regimes of MK-933 (ivermectin) in human onchocerciasis.
TLDR
Ivermectin slowly eliminated microfilariae from the skin and eye without serious adverse clinical or ocular reactions in all treated groups and would reintroduce new concepts of the role of chemotherapy in the control of onchocerciasis.
Effects of three-month doses of ivermectin on adult Onchocerca volvulus.
TLDR
Ivermectin given at 3-month intervals was effective in preventing embryogenesis to the microfilarial stage while, at the same time, it caused a slow but steady attrition of the adult worms.
The effect of repeated doses of ivermectin on adult female Onchocerca volvulus in Sierra Leone.
  • D. Chavasse, R. Post, P. A. Lemoh, J. Whitworth
  • Medicine, Biology
    Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft fur Technische Zusammenarbeit
  • 1992
TLDR
The effects of single and multiple doses of ivermectin on mortality and morphology were assessed in over 700 female Onchocerca volvulus worms and the effects on embryogenesis were assessed, and almost complete cessation of embryogenesis was observed.
Large scale ivermectin distribution and its epidemiological consequences.
TLDR
Ivermectin treatment appears to be the most appropriate method for control of recrudescence of infection in an area where the parasite reservoir has been virtually eliminated by vector control, such as in the core area of the OCP.
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