Scientists near ‘cure’ for malaria, dengue, Zika, others
Mosquito-Borne diseases such as malaria, dengue, West Nile virus, chikungunya, yellow fever, filariasis and Zika may soon become history, as scientists have developed a technique that sterilises male mosquitoes using radiation.
The World Health Organisation (WHO)-led scientists, yesterday, announced that the Sterile Insect Technique (SIT), a form of insect birth control, would soon be tested as part of global health efforts to control mosquito-borne diseases.
The process involves rearing large quantities of sterilised male mosquitoes in dedicated facilities, and then releasing them to mate with females in the wild. As they do not produce any offspring, the insect population declines over time.
According to WHO, with the Special Programme for Research and Training in Tropical Diseases (TDR) and the International Atomic Energy Agency (IAEA), in partnership with the Food and Agriculture Organisation (FAO) of the United Nations, it has developed a guidance document for countries that have expressed interest in testing the SIT for Aedes (yellow fever) mosquitoes.
Mosquito-borne illnesses are caused by bacteria, viruses or parasites transmitted by mosquitoes. They can transmit disease without being affected themselves. It is estimated that nearly 700 million people get a mosquito-borne illness each year resulting in over one million deaths and account for about 17 per cent of all infectious diseases globally.
Other diseases transmitted by mosquitoes include tularemia, dirofilariasis, Japanese encephalitis, Saint Louis encephalitis, Western equine encephalitis, Eastern equine encephalitis, Venezuelan equine encephalitis, Ross River fever, Barmah Forest fever, La Crosse encephalitis, and Zika fever, as well as newly detected Keystone virus and Rift Valley fever.
The SIT was first developed by the United States Department of Agriculture and has been used successfully to target insect pests that attack crops and livestock, such as the Mediterranean fruit fly and the New World screwworm fly. It is currently in use globally in the agriculture sector on six continents.
The guidance on using the technique to control diseases in humans recommends adopting a phased approach that allows time to test the efficacy of the sterilised insects. Epidemiological indicators monitor the impact of the method on disease-transmission. It also provides recommendations on mass production of the sterile mosquitoes, government and community engagement, measuring the impact of the technique, and assessing cost-effectiveness.
WHO chief scientist, Dr. Soumya Swaminathan, said: “Half the world’s population is now at risk of dengue. And despite our best efforts, current efforts to control it are falling short. We desperately need new approaches, and this initiative is both promising and exciting.”
In recent decades, the incidence of dengue has increased dramatically due to environmental changes, unregulated urbanisation, transport and travel, and insufficient sustainable vector control tools and their application.
Dengue outbreaks are currently occurring in several countries, notably on the Indian sub-continent. Bangladesh is facing the worst outbreak of dengue since its first recorded epidemic in 2000. The South Asian nation has seen the number of cases rise to over 92,000 since January 2019, with daily admissions peaking at more than 1,500 new dengue patients in hospitals in recent weeks and is one of the countries to express interest in the Sterile Insect Technique.
The 2015 outbreak of Zika in Brazil was linked to an increase in the number of babies being born with microcephaly. A scientist at TDR, Florence Fouque, said: “Countries seriously affected by dengue and Zika have shown real interest in testing this technology as it can help suppress mosquitoes that are developing resistance to insecticides, which are also negatively impacting the environment.”
The collaborative effort includes plans to support three multi-country teams of research institutions, vector control agencies and public health stakeholders to test the Sterile Insect Technique against Aedes mosquitoes.
Medical entomologist at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Jérémy Bouyer, said: “The use of the Sterile Insect Technique in the agriculture sector in the past 60 years has shown that it is a safe and effective method. We are excited to collaborate with TDR and WHO to bring this technology to the health sector to fight human diseases.”
TDR, the Special Programme for Research and Training in Tropical Diseases, is a global programme of scientific collaboration that helps facilitate, support and influence efforts to combat diseases of poverty. It is co-sponsored by the United Nations Children’s Fund (UNICEF), the United Nations Development Programme (UNDP), the World Bank and WHO.
No comments yet