Representational image (iStock)

A NEW trial using ‘manipulated mosquitoes’, which spread the Dengue fever, has resulted in a 77 per cent fall in total cases.

scientists used mosquitoes infected with “miraculous” bacteria that reduce the insect’s ability to spread dengue in a  trial took place in Yogyakarta city, Indonesia, reported the BBC.

The trial used mosquitoes infected with Wolbachia bacteria. One of the researchers, Dr Katie Anders, describes them as “naturally miraculous”.

Wolbachia doesn’t harm the mosquito, but it camps out in the same parts of its body that the dengue virus needs to get into.

According to the report, the bacteria compete for resources and make it much harder for dengue virus to replicate, so the mosquito is less likely to cause an infection when it bites again.

The World Mosquito Programme team says it could be a solution to a virus that has gone around the world, the report added.

In 1970, only nine countries had faced severe dengue outbreaks, now there are up to 400 million infections a year.

Dengue is commonly known as ‘break-bone fever’ because it causes severe pain in muscles and bones and explosive outbreaks can overwhelm hospitals.

The trial used five million mosquito eggs infected with Wolbachia. Eggs were placed in buckets of water in the city every two weeks and the process of building up an infected population of mosquitoes took nine months.

Yogyakarta was split into 24 zones and the mosquitoes were released only in half of them.

The results, published in the New England Journal of Medicine, showed a 77 per cent reduction in cases and an 86 per cent reduction in people needing hospital care when the insects were released.

“It’s very exciting, it’s better than we could have hoped for to be honest,” Dr Anders told the BBC.

The technique has been so successful the mosquitoes have been released across the whole city and the project is moving to surrounding areas with the aim of eradicating dengue in the region.

Wolbachia are also spectacularly manipulative and can alter the fertility of their hosts to ensure they are passed on to the next generation of mosquitoes.

“We are delighted with the outcome of this trial. We hope this method can be implemented in all areas of Yogyakarta and further expanded in all cities in Indonesia,” Dr Yudiria Amelia, the head of disease prevention in Yogyakarta City, told the BBC.

The trial is a significant landmark after years of research as the species of mosquito that spreads dengue – Aedes aegypti – is not normally infected with Wolbachia.

Disease modelling studies have also predicted Wolbachia could be enough to completely suppress dengue fever if it can be established.

According to David Hamer, a professor of global health and medicine at Boston University, the method had ‘exciting potential’ for other diseases such as Zika, yellow fever and chikungunya; which are also spread by mosquito bites.