Genetically modified male mosquitoeswho sire offspring that die early on have in the end been release in Brazil to oppress breakbone fever . And allot to outcome published inPLOS Neglected Tropical Diseaseslast workweek , these “ unfertile ” skeeters have reduced the dengue mosquito population in one Brazilian suburbia by 95 % .
Dengue(also known as “ bone breaker ” ) taint as many as 390 million people a year . It ’s the second most significant mosquito - borne disease after malaria , but unlike malaria , dengue is increase in both relative incidence and stiffness . There are no specific drugs nor licensed vaccine to treat this infective disease , at least not yet . Its primary vector isAedes aegypti , and researcher around the world have been developing a so - call ego - limiting gene : When a transgenic male mates with a wild female , the transgene is slip by to embryos through sperm , leading to larvae death before they ’re honest-to-goodness enough to bulge channelise disease .
In the last few years , a self - limiting strain called OX513A reach the field rating phase after extensive lab tests . Releases of OX513A males in the Cayman Islands in 2010 led to 80 % crushing of a butt universe , while isolated field demonstrations in Brazil have achievedsimilarly successful resultsafter six months .
Then , commence in 2011 , a team led by Andrew McKemey ofOxitecconducted a free burning serial publication of OX513A subject field releases in Itaberaba , a suburb of Juazeiro in the semi - desiccate northeastern area of Brazil . Because pipe piddle service are irregular in this slow suburb , the 1,810 residents look on store urine – idealistic habitats forAedes aegypti . Throughout the study , local mosquito ascendancy was deployed as normal : Public wellness agentive role continued to destroy training sites and treat homes with larvicide .
Just over a year by and by , the localAedes aegyptipopulation was deoxidize by 95 % found on adult hole data . According to a disjoined measure based on ovitraps ( which mimic breeding land site ) , the population was reduced by 81 % . " For context , with presently uncommitted method include pesticides – the in force you’re able to get is about 50 % reduction – not enough to prevent the epidemic spread of disease , " Oxitec chief operating officer Hadyn Parry tell IFLScience . Sustained exit of OX513A males , the investigator say , may therefore be an effective and widely useful method for suppressing the dengue vector and preventing epidemics .
“ In hypothesis , if you have fewer mosquitoes you have less contagion , but in realism , this is something we still need to investigate , ” study atomic number 27 - authorMargareth Capurro from the University of São PaulotellsNew Scientist . “ you may have lots of mosquitoes with only a few infected , or very few with all of them taint , ” she adds . “ If this happen , you inhibit the population but do n’t affect dengue transmission . ” But plans are in seat to guide depth psychology of correlations between mosquito turn and dengue cases , and if the studies are conducted on a sufficiently large enough scale , then the scientist should be able to deduce whether statistically significant reduction in dengue have occurred , Parry tells IFLScience .
This past April , six million of these modified mosquito , sleep with topically as “ friendlyAedes aegypti , ” were give up in the Brazilian metropolis of Piracicaba , which is facing one of the bad infestation . “ The next stone’s throw is to scale up to even larger studies and run for mosquito controller projects on an operational ground , ” McKemey says in astatement . The society is waiting for permission from the U.S. Food and Drug Administration to test in the Florida Keys . Although this area has been breakbone fever - loose since 2010 , there are awe that it could come back , which is why there is interest in testing out Oxitec ’s technology , Parry say .
