“Miraculous” mosquito tinkering slashes dengue cases by three quarters
Dengue fever cases fell by 77 per cent in a “groundbreaking” trial where mosquitoes armed with a virus-fighting bacteria were released into areas of an Indonesian city, scientists have said.
The “groundbreaking” trial in Yogyakarta city used five million mosquito eggs infected with Wolbachia, a bacteria that limits mosquitos’ ability to spread the disease without harming them.
Mosquitoes that had the Wolbachia bacteria had initially only been released across half of Yogyakarta but the results, published in the New England Journal of Medicine, were so successful that the parasites were released across the whole city.
In the areas where the insects were released, the trial showed a 77 per cent reduction in cases and an 86 per cent reduction in people needing hospital care.
The disease-fighting mosquitoes are now being rolled out further in the hope of eradicating dengue, which is commonly known as break-bone fever because it causes severe pain in muscles and joints.
While many dengue cases produce only mild illness, the infection can cause an acute flu-like illness. Occasionally this develops into a potentially lethal complication called severe dengue.
The potential to prevent severe dengue through Wolbachia is a significant breakthrough for global health. Few people had heard of the virus 50 years ago, but global incidence of the virus has grown dramatically in recent decades.
Severe dengue is a leading cause of serious illness and death in some Asian and Latin American countries and the World Health Organisation (WHO) says there is now the possible threat of an outbreak in Europe.
There are an estimated 100-400 million dengue infections each year and the WHO warns that around half of the world’s population is now at risk.
Dr Katie Anders, director of impact assessment at the World Mosquito Programme, described the Wolbachia bacteria as “naturally miraculous” and the trial results as “groundbreaking”.
She said: “We think it can have an even greater impact when it is deployed at scale in large cities around the world, where dengue is a huge public health problem.”
Disease modelling studies have predicted Wolbachia could be enough to completely suppress dengue fever if it can be established.
David Hamer, professor of global health and medicine at Boston University, said the results of the trial also held “exciting potential” for other mosquito-borne diseases such as Zika, yellow fever and chikungunya.