A technique that sterilizes male mosquitoes with radiation will soon be tested as part of a global health effort to fight diseases such as chikungunya, dengue and zika.
The Sterile Insect Technique (SIT) is a form of insect birth control. The process involves raising large numbers of sterilized male mosquitoes in special facilities and releasing them to mate with females in the wild. Since they do not produce any offspring, the insect population will decrease over time.
The Special Program for Research and Training in Tropical Diseases (TDR) and the International Atomic Energy Agency (IAEA), in collaboration with the Food and Agriculture Organization of the United Nations (FAO) and the WHO, have developed a guidance document for countries that have expressed interest in it who have tested the Sterile Insect Technique (SIT) on Aedes mosquitoes.
Half the world is threatened by dengue
“Half the world’s population is now at risk of dengue fever,” said Dr. Soumya Swaminathan, WHO chief scientist. “And despite our best efforts, current efforts to control this are failing. We urgently need new approaches and this initiative is both promising and exciting. ”
Over the past few decades, the incidence of dengue has increased dramatically due to environmental changes, unregulated urbanization, traffic and travel, and inadequate tools for sustainable vector control and their application.
Dengue outbreaks are currently occurring in several countries, particularly the Indian subcontinent. Bangladesh is facing the worst dengue outbreak since its first recorded epidemic in 2000. In the South Asian nation, the number of cases has risen to over 92,000 since January 2019, with daily admissions peaking in more than 1,500 new dengue patients in hospitals in recent weeks, and is one of the countries showing interest in sterile insect technology .
Diseases carried by mosquitoes such as malaria, dengue fever, zika, chikungunya, and yellow fever account for around 17% of all infectious diseases worldwide. More than 700,000 people die each year and many more suffer. The 2015 Zika outbreak in Brazil was linked to an increase in the number of babies born with microcephaly.
New techniques have proven effective against insects that attack crops and livestock
Sterile insect technology was first developed by the U.S. Department of Agriculture and has been successfully used to control insect pests that attack crops and livestock such as the Mediterranean fruit fly and the New World Screwworm Fly. It is currently used worldwide in agriculture on six continents.
The Guidelines on Using the Technique to Control Disease in Humans recommend a step-by-step approach, leaving time to test the effectiveness of the sterilized insects. Epidemiological indicators monitor the impact of the method on disease transmission. It also includes recommendations on how to mass-produce the sterile mosquitos, government and community engagement, measure the impact of the technique, and assess cost-effectiveness.
“Countries severely affected by dengue and Zika have shown great interest in testing this technology as it can help suppress mosquitoes that are developing resistance to insecticides that also have negative environmental effects.” said Florence Fouque, a scientist at TDR.
The collaboration includes plans to support three teams from research institutes, vector control agencies and public health stakeholders in several countries to test sterile insect technology against Aedes mosquitoes. “The use of sterile insect technology in agriculture over the past 60 years has shown it to be a safe and effective method,” said Jérémy Bouyer, medical entomologist with the FAO / IAEA Joint Division on Nuclear Techniques in Food and Agriculture. “We are excited to work with TDR and WHO to use this technology in the health sector to fight human diseases.”
Note to editors
TDR, the Special Program for Research and Education in Tropical Diseases, is a global program of scientific collaboration that helps facilitate, support, and influence efforts to combat poverty-related diseases. It is jointly sponsored by the United Nations Children’s Fund (UNICEF), the United Nations Development Program (UNDP), the World Bank and the WHO.