COUNTDOWN implementing alternative strategies for onchocerciasis control and elimination in Cameroon
In Cameroon, the team are exploring alternative strategies of test-and-treat with doxycycline, either alone or combined with a pilot ground larviciding to reduce the blackfly biting rate in the selected site area – Meme Basin in the South West Region of Cameroon. This work is led by Professor Samuel Wanji and carried out by the Buea team in partnership with colleagues from LSTM including Prof Mark Taylor, Dr Joe Turner and Dr Louise Hamill.
Epidemiological and entomological evaluations conducted by our research team in the Meme river basin in the South West Cameroon confirmed an ongoing transmission of onchocerciasis despite 15years of uninterrupted annual ivermectin mass drug administration (MDA). To move quickly in interrupting the infection and the elimination of onchocerciasis, a change in treatment strategy is necessary. Unlike Ivermectin, doxycycline is a curative treatment for onchocerciasis; it will clear the infection of those who receive the treatment. In combined doxycycline and vector control areas, complementary ground larviciding in identified breeding sites along the Meme river will help to reduce the number of blackfly biting rate and therefore reduce the transmission of Onchocerca volvulus infection.
Aim and objectives
The aim of this implementation research is to assess the effectiveness, feasibility, acceptability and cost effectiveness of test-and fast-track the elimination of onchocerciasis in the Meme river basin in the South West Region of Cameroon.
Our specific objectives with this research:
- Reduce Community Microfilaria Loads (CMFL) in selected communities in the Meme river basin
- Reduce blackfly infection rate in Simulium breeding sites identified in the Meme river basin
- Assess how tolerable and acceptable doxycycline is together with ground larviciding
- Determine how economical it will be to implement the two arms of the alternative strategies in the study area
To achieve these objectives, the following activities will be conducted:
- One round of Doxycycline treatment using a test-and-treat strategy in communities within the hotspot area
- Ground larviciding of identified Simulium breeding sites along the Meme river and tributaries for ten weeks after doxycycline test-and-treat implementation.
- Focus group discussions and in-depth interviews with different stakeholders to assess the acceptability and tolerability of doxycycline and bi-annual distribution of ivermectin.
Research objectives
- Determine the risk factors for sub-optimal effectiveness of current CDTi strategy in the SW Province, Cameroon
- Determine the effectiveness of implementing alternative strategies for onchocerciasis (namely test and treat with doxycycline and ground larviciding) in the control or focal elimination of onchocerciasis
- Capture societal and health economic data to assess the acceptability, feasibility and cost effectiveness of alternative strategies for onchocerciasis control and elimination
Study design
In total, 30 communities are targeted and 20 communities will be enrolled into community-led test-and-treat with doxycycline (TTd). In 10 of these communities, situated along upper Meme tributaries, a ground larviciding treatment against the blackfly vector will also occur whilst the other ten fluvio-geographically isolated communities will be enrolled into TTd only. An additional ten communities will receive only standard care and parasitological monitoring, without additional intervention. CDTi (Community Directed Treatment with Ivermectin which is annual ivermectin standard care) will continue in all communities.