Read at 3 different speeds

Scientists reduce dengue by 77% - 21st June 2021

Dengue fever cases have been cut by 77% following a ground-breaking trial that manipulates the mosquitoes that spread it.

The trial used mosquitoes infected with bacteria that hinder the insect's ability to transmit the disease. Conducted in Yogyakarta city, Indonesia, it is now being expanded in the hope of eradicating the virus. The World Mosquito Programme believes the method could be a gamechanger in the fight against a virus which, in recent years, has spread around the globe.

Half a century ago, dengue was a little-known disease. However, the number of yearly infections can now reach up to 400 million. The virus is commonly known as "break-bone fever" because sufferers experience severe muscle and bone pain and hospitals often struggle with large outbreaks.

The trial involved the infection of five million mosquito eggs with Wolbachia bacteria, described by researcher Dr Katie Anders as "naturally miraculous." Harmless to the mosquito itself, Wolbachia camps out in the same parts of its body as dengue. The bacteria competes for resources, making it much harder for the virus to replicate. This greatly decreases the chance of the mosquito passing on the dengue to humans.

The infected eggs were placed in buckets of water in the city every two weeks. The process of building up an infected population of mosquitoes took nine months. The startling results of the trial showed a 77% drop in cases of dengue fever and an 86% decline in the number of hospitalisations due to infection.

David Hamer, a professor of Global Health and Medicine at Boston University, said the method had "exciting potential" for other diseases spread by mosquitoes; such as Zika, yellow fever and chikungunya.