STORY: As Brazil confronts a massive dengue outbreak, the city of Suzano hopes part of the solution is inside these boxes. Fueled by a hot rainy season, more than 973,000 likely dengue cases have been detected in Brazil so far this year.The boxes contain a version of the male Aedes aegypti mosquito developed by British biotechnology company Oxitec.The modified mosquitoes carry a gene that kills female offspring before they reach maturity. Only female mosquitoes bite and transmit diseases.The modified mosquitoes stay inside the box for about 10 days before coming out, says Oxitec's Natalia Ferreira.“When we release the 'Aedes do bem' in a certain neighbourhood and compare the mosquito population with that of a neighbourhood where it was not used, we always have more than 90% suppression of the population. In other words, the treated neighbourhood has 90% fewer mosquitoes than the neighbourhood where there was no release.”Suzano is among the cities using the solution after declaring a state of emergency earlier this month. The city's mayor said he hopes the next measurement will show a reduction in cases by 20% so the emergency can be lifted. According to Brazil’s health ministry, 195 people died because of the disease, while hundreds of cases remain under investigation.