Can You Insert a Knitting Needle into a Water Balloon Without Popping It?

That’s kind of what scientists are doing to prevent dengue fever.

Dengue fever is a deadly mosquito-borne virus that plagues the earth, but science is inching closer to an unlikely solution: bacteria.

Most of the microbes around us are harmless, or even beneficial, but some that can cause serious illness or even death. The dengue virus is estimated to infect over 400 million people every year and is usually transmitted through the Aedes aegypti mosquito. Scientists have spent years trying to find a way to stop the spread of dengue, and one of them has come up with a surprising solution. Ed Yong talks with Scott O’Neill, Professor at Monash University and leader of the Eliminate Dengue project, about his plan to infect the mosquito with a bacteria called Wolbachia that spreads through the mosquito population and stops the transmission of dengue. Only problem? Although Wolbachia is naturally present in many different species of insects, it is usually not found in Aedes aegypti. So O’Neill had to get Wolbachia bacteria into the mosquito embryo — a painstaking challenge: “Imagine that you need to insert a knitting needle into a balloon full of water,” O’Neill says, “and then pull the knitting needle out without the balloon breaking.” O’Neill succeeded, and pilot studies with the Wolbachia-infected mosquitoes suggest that Wolbachia has great power to reduce the spread of dengue in people.

I Contain Multitudes is a multi-part video series dedicated to exploring the wonderful, hidden world of the microbiome. The series is hosted by science writer Ed Yong and produced by HHMI Tangled Bank Studios in association with Room 608.