a mosquito Factory in Brazil is about to unleash 5 billion infected mosquitoes across the country for the first time ever is this the beginning of a sci-fi film or one of the most ingenious bits of science I've come across in a Long Time spoiler alert it's the ladder we all hate mosquitoes right and not for no reason on top of being a pure nuisance with their buzzing and itchy bites they're actually the deadliest animal to humans literally they kill more humans than any other creature primarily through spreading disease but before we can understand and why
scientists would want to make more of them we should ask ourselves the question couldn't we just destroy them all like would it really be so bad if we killed every mosquito on Earth nature Journal actually did an analysis on this exact question and found that there wouldn't actually be a huge Fallout if mosquitoes disappeared tomorrow at least not for humans and even then very few species heavily rely on mosquitoes the ones that do like some birds and fish would likely replace them with something else and while some mosquitoes do act as pollinators there's nothing humans
rely on them exclusively for of course there's like 3,200 species of mosquito and only 200 of them bite humans so it seems unfair to kill them all but because of the ones that do bite us around 247 million people are infected with malaria every year not to mention a myriad of other diseases like Deni and zika but while destroying mosquitoes may be a net positive for humans one is it really that feasible to do and two can we really know the ecological Fallout from something of that magnitude in comes the idea to make more mosquitoes
in a factory which sounds crazy until you realize it's not you see scientists have discovered a way to stop disease transmission from mosquitoes without the need for killing them all thanks to a bacteria called wakia wakia has sort of been in the background in mosquito biology if you like for the last 100 years but only quite recently attracting a lot of attention some of the work that we did a number of years ago now showed that if you had W back here in the mosquito that transmits viruses to people like yellow fever chcken Gia Dy
the viruses couldn't grow very well in the mosquito if the head will back here in them this was confusing to the scientists at first but they realized that the bacteria is likely out competing any other pathogens like the Deni virus so if wakia is present the virus is unable to proliferate properly and ultimately can't spread to humans and if you take some of these wakia infected mosquitoes and let them loose into the wild they'll end up infecting other mosquitoes with wakia if an infected male mates with a noninfected female the eggs She lays won't hatch
if the female has it and the male doesn't her eggs will hatch but they'll all be infected with wakia and the same happens if both are infected after a few Generations the number of wakia carrying mosquitoes increases rapidly we've done you know deployments in 14 countries usually our release programs last anywhere from a couple of months to maybe 6 months and that provides the opportunity for those mosquitoes to make little wild mosquitoes and then pass W back here into that wild mosquito population most importantly Den cases dropped significantly one of the first comprehensive studies in
Indonesia found the protective efficacy of the intervention was 77.1% that's the equivalent of being four times less likely to develop the disease if you were in those areas now some test sites saw results as low as 38% but still pretty major for the reduction of a disease the lower results may be because it takes longer in some communities depending on their size and environment for wakia to spread to the entire mosquito population however the most recent results from the abura valley Colombia which were just released in November 2023 actually saw a decline of 95 to
97% in D fever bringing it to the lowest rate in 20 years for the region what makes this result even more profound is that the rest of the americaas actually had the second worst year for Deni fever since 1980 so while some parts of Colombia were seeing record highs of Denay this region where modified mosquitoes were Unleashed saw record lows this Colombia project began releasing wakia infected mosquitoes in 2015 so to see a 95% reduction in Deni fever is pretty astounding and now the teams are trying to figure out how to deploy these modified mosquitoes
as effectively as possible over even larger areas Deni is a huge problem in Brazil as zika has then we are working together to produce a facility that will produce up to 100 million mosquitoes a week uh in Brazil so that we can deploy them over multiple Brazilian cities now you might be wondering are humans being infected with the wakia in these mosquitoes like is there a larger risk of having so much of it in our environment so about 50% of all insects naturally have wakum I can guarantee that you and everybody that listens to this
will have been bitten by what we call the common housee mosquito that's the mosquito that's just IND descript Brown mosquito that will buzz around your ears and that mosquito naturally has vakia in it vakia was a problem we'd know about it there's not a link between wak here and any negative outcomes that anyone's been able to find currently the wh is evaluating this technology for use in other countries of course the scientists involved see this as a supplementary measure and not meant to prevent or discourage Deni vaccines in the regions that are at high risk
but in the long run it could end up saving hundreds of millions of people from being infected by Deni and around 100 million people from getting sick it's all an amazing reminder how Innovation and sometimes an unexpected approach can literally change the lives of hundreds of millions of people for the better I want to send a big thanks to Dr O'Neal for helping me to break down this incredible science thanks so much for watching if you liked it give it a thumbs up and subscribe for more science ASAP peace
