ArticlePLoS neglected tropical diseases2021
The Mbam drainage system and onchocerciasis transmission post ivermectin mass drug administration (MDA) campaign, Cameroon.
Article in PLoS neglected tropical diseases, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers, 1 of them a synthesis that pooled it.
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12 citing papers in PubMed, 1 synthesis or guideline pooled it, 21 citations in OpenAlex.
- Current Gaps in Survey Design and Analysis for Molecular Xenomonitoring of Vector-Borne Neglected Tropical Diseases: A Systematic Review.Tropical medicine & international health : TM & IH · 2025Pooled it
- The risk of onchocerciasis infection by human population movements between high and low transmission settings in Ghana.PLoS neglected tropical diseases · 2026Article
- Simulium larvae susceptibility to temephos and the effect of 10 weeks of treatment of the Mbende tributary in the Nkam-Wouri River drainage of Cameroon on larval density and adult fly biting rates.Parasites & vectors · 2025Article
- Model-Based Geostatistical Mapping of the Prevalence of Onchocerca volvulus in Cameroon between 1971 and 2020.PLoS neglected tropical diseases · 2025Article
- The Impact of Onchocerciasis Elimination Measures in Africa: A Systematic Review.Tropical medicine and infectious disease · 2024Review
- Comparison of standard and modified human landing catching techniques for blackfly collection.International health · 2024Article
- Optimized strategy for real-time qPCR detection of Onchocerca volvulus DNA in pooled Simulium sp. blackfly vectors.PLoS neglected tropical diseases · 2023Article
- Evaluating the impact of alternative intervention strategies in accelerating onchocerciasis elimination in an area of persistent transmission in the West Region of Cameroon.PLoS neglected tropical diseases · 2022Article
- Geospatial modeling of pre-intervention nodule prevalence of Onchocerca volvulus in Ethiopia as an aid to onchocerciasis elimination.PLoS neglected tropical diseases · 2022Article
- Development and implementation of a simple and rapid extraction-free saliva SARS-CoV-2 RT-LAMP workflow for workplace surveillance.PloS one · 2022Article
- Onchocerca volvulus transmission in the Mbam valley of Cameroon following 16 years of annual community-directed treatment with ivermectin, and the description of a new cytotype of Simulium squamosum.Parasites & vectors · 2021Article
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19 authors at 4 institutions in 5 countries.
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Abstract
backgroundThe impact of large scale Mass Drug Adminstration (MDA) of ivermectin on active onchocerciasis transmission by Simulium damnosum, which transmits the parasite O. volvulus is of great importance for onchocerciasis control programmes. We investigated in the Mbam river system area, the impact of MDA of ivermectin on entomological indices and also verify if there are river system factors that could have favoured the transmission of onchocerciasis in this area and contribute to the persistence of disease. We compared three independent techniques to detect Onchocerca larvae in blackflies and also analyzed the river system within 9 months post-MDA of ivermectin.
methodSimulium flies were captured before and after 1, 3, 6 and 9months of ivermectin-MDA. The biting rate was determined and 41% of the flies dissected while the rest were grouped into pools of 100 flies for DNA extraction. The extracted DNA was then subjected to O-150 LAMP and real-time PCR for the detection of infection by Onchocerca species using pool screening. The river system was analysed and the water discharge compared between rainy and dry seasons. PRINCIPAL
findingsWe used human landing collection method (previously called human bait) to collect 22,274 adult female Simulium flies from Mbam River System. Of this number, 9,134 were dissected while 129 pools constituted for molecular screening. Overall biting and parous rates of 1113 flies/man/day and 24.7%, respectively, were observed. All diagnostic techniques detected similar rates of O. volvulus infection (P = 0.9252) and infectivity (P = 0.4825) at all monitoring time points. Onchocerca ochengi larvae were only detected in 2 of the 129 pools. Analysis of the river drainage revealed two hydroelectric dams constructed on the tributaries of the Mbam river were the key contributing factor to the high-water discharge during both rainy and dry seasons.
conclusionResults from fly dissection (Microscopy), real-time PCR and LAMP revealed the same trends pre- and post-MDA. The infection rate with animal Onchocerca sp was exceptionally low. The dense river system generate important breeding sites that govern the abundance of Simulium during both dry and rainy seasons.
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