‘Bug birth control’ to save human lives

©Ian Jabobs

Mosquitoes are one of the deadliest animals on earth.

Their ability to carry and spread disease to humans account for more than 17% of all infectious diseases, claiming over 700 000 lives each year.

Cases of dengue — a major killer and cause of serious illness in Asian and South American countries — have risen dramatically in recent years, with up to 390 million infections each year. The estimated number of deaths due to dengue has also increased to 40 000.

Symptoms range from mild to severely flu-like, with a high temperature, severe headache, nausea, vomiting and muscle and joint pain.

©Joshua Cogan

Zika, dengue, chikungunya, yellow fever and Rift Valley fever are all transmitted to humans by the Aedes aegypti mosquito. Four billion people are at risk of Aedes-borne diseases in 128 countries.

Mosquito control is important to prevent outbreaks and people from getting sick from these diseases. However, the current control measures are falling short because they are not sustainable.

Historically, insecticides have been the main tool to control mosquito populations, but the insects are developing resistance to the chemicals, which can also harm the environment.


Bug birth control

A new form of bug birth control may help stop the spread of mosquito-borne diseases.

The Sterile Insect Technique involves rearing millions of male mosquitoes and sterilizing them by radiation.

But we’re not talking glowing green nuke-bugs here — the radiation is only enough to make them sterile.

Once sterile, waves of male mosquitoes are released into target areas to mate with females in the wild. The eggs produced are not viable and do not hatch.

As male mosquitoes don’t bite and don’t produce any offspring, the insect population declines.

Sterile mosquitoes are generally released by ground in ongoing trials, but promising results were recently obtained in Brazil with a drone release system. ©TDR/F. Fouque

Combining traditional control measures with systematic and repeated release of sterile males aims to reduce the mosquito populations sufficiently to prevent disease transmission and reduce human suffering.

The technique of sterilizing insects was first developed by the US Department of Agriculture and has been used successfully for over 60 years to target insects that attack crops and livestock. It’s currently in use worldwide in the agricultural sector.

Countries hard-hit by dengue and Zika in particular have shown real interest in testing the technology, and, so far, the tactic has been tested at small-scale in Brazil, Cuba, Germany, Mauritius and Mexico.

Larger-scale pilot releases are planned for next year.

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