Miraculous bacteria reduces dengue cases by 77%
Using mosquitoes infected with a “miraculous” bacteria that reduces the insect’s ability to spread dengue, researchers in Yogyakarta city, Indonesia, have managed to cut down dengue cases by an impressive 77% in part of the city. The groundbreaking technique is to be adopted across the whole city and surrounding areas in the hopes of eradicating dengue in the region.
Outbreaks of dengue, spread by the Aedes aegypti mosquito, can reach up to 400 million cases each year; it is commonly known as “break-bone fever” because it causes severe pain in muscles and bones. Like any other disease, explosive outbreaks of dengue can overwhelm hospitals in many affected countries.
According to researchers of the World Mosquito Programme, the trial in Yogyakarta used five million mosquitoes infected with Wolbachia, a “naturally miraculous” bacterium. Wolbachia doesn’t harm the mosquito or the human host but camps out in the same parts of its body that the dengue virus needs to get into; the competition makes it much harder for dengue virus to replicate, so the mosquito is less likely to cause an infection when it bites again.
Mosquito eggs infected with Wolbachia were placed in buckets of water in around 12 zones in the city every two weeks. The process of building up an infected population of mosquitoes took nine months. The results showed a 77% reduction in cases and an 86% reduction in people needing hospital care after the mosquitos were released.
Wolbachia can also alter the fertility of their hosts to ensure they are passed on to the next generation of mosquitoes; once Wolbachia has been established, it should stick around for a long time and continue to protect against dengue infection. This is in sharp contrast to other control methods such as insecticides or releasing large numbers of sterile male mosquitoes that need to be kept up in order to suppress their numbers.
David Hamer, a professor of global health and medicine at Boston University, said the method – if executed properly – had “exciting potential” for other diseases such as Zika, yellow fever and chikungunya; which are also spread by mosquito bites.
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