By Carley Willis and James Howlett
Diseases passed on by mosquitoes can cause sickness and economic hardship. As mosquitoes become increasingly resistant to insecticides, which also cause pollution, many governments are considering alternative forms of mosquito control – including with the use of nuclear techniques.
Through a collaboration between the IAEA, the Food and Agriculture Organization of the United Nations (FAO), the Special Programme for Training and Research of Tropical Diseases (TDR) and the World Health Organization (WHO), the Guidance Framework for Testing the Sterile Insect Technique as a Vector Control Tool against Aedes-Borne Diseases was released earlier this month. Written with the involvement of 15 experts from 12 countries, it will serve as guidance for countries interested in using this technique. The development of these guidelines and the publication of the document were jointly financed by the TDR, the WHO and the IAEA’s technical cooperation programme and Peaceful Uses Initiative.
“Regulatory procedures in public health are usually strict,” said Head of Biological Control of Vectors Group at the Institute of Tropical Medicine Pedro Kouri in Cuba, Rene Gatos Armas. “In this sense, the guidelines will facilitate the implementation of both research and operational programs.”
What is the Sterile Insect Technique (SIT)? It is an insect birth control method. Radiation is used to sterilize male mosquitoes, which are then released to mate with wild females resulting in no offspring. Overtime this leads to a decline in the mosquito population and in the diseases they carry.
SIT is an environmentally friendly technique to gradually lessen the transmission of Aedes-borne diseases. This is a species-specific form of insect control, initially invented to control agricultural pests such as tsetse flies and fruit flies, which avoids risking other species and ecosystems.
“One of the great values of this guide is that it harmonizes the SIT approach and its application for all IAEA Member States who are interested in adding an environmentally-friendly tool to their tool kit to reduce the vector that carries diseases,” said the IAEA’s Programme Management Officer who is overseeing a related regional project in Latin America and the Caribbean, Patricia Godoy-Kain.
SIT has historically been used against agricultural pests, attacking crops and livestock. The IAEA and the FAO, through their Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, has been providing technical support to over 60 countries in implementing SIT technology. It has now been adapted for use against Aedes mosquitoes.
“Brazil has faced challenges in different components of the SIT implementation for Aedes mosquitoes,” said Technical-Scientific Manager at Biofabrica Moscamed Brasil, Maylen Gomez Pacheco. “The Guidance Framework is an excellent initiative for strengthening and harmonizing the knowledge among IAEA Member States. This reference document will enable them to move along the different steps of SIT with confidence.”
The document guides experts on how to fight diseases brought on by Aedes mosquitoes such as chikungunya, dengue, yellow fever and Zika, which cause over a million deaths per year. The nine chapters outline how a programme can be initiated first through a pilot phase so decisions can be made whether or not to implement the technique to the country’s affected areas.
The document also covers aspects of scaling-up the action programme and its full implementation, risk assessment and regulatory frameworks, technical topics such as the mass-rearing of insects, and entomological and epidemiological indicators. Also, it offers guidance on engaging communities, ensuring cost-effectiveness and carrying out effective programme monitoring and evaluation.
Through an IAEA technical cooperation project, the SIT technique was recently implemented for the first time in Greece against Aedes mosquitoes. “It is important to continue building on the research and implementation of SIT on mosquitoes, sustaining efforts from small-scale plot validation tests to operational large scale trials,” said Research Director for the Department of Entomology and Agricultural Zoology at the Benaki Phytopathological Institute in Greece, Antonios Michaelakis. Considered to be at high-risk for diseases transmitted by Aedes mosquitoes, Greece has been running projects to minimize this risk. “The objectives of the current joint Guidance Framework for evaluating the impacts of SIT is very important to provide the necessary and sufficient information for further studies,” he added. Carley Willis and James Howlett are both of the IAEA Office of Public Information and Communication and Department of Technical Cooperation, respectively.