Mosquitoes with lethal genes to help Brazil fight dengue

When he announced he was going to Brazil for the World Cup, Andy Quinn was warned by friends and a travel agent to lather on mosquito repellent to avoid potentially fatal dengue fever. Some of the mosquitoes he saw “were like aliens — I’ve never seen them that big before,” said the 32-year-old Londoner, who attended three games in Brazil before his England team was sent packing. Brazil’s stepped up spraying of insecticides didn’t seem to help matters. The country may soon have a more powerful weapon to use before it hosts the 2016 Summer Olympics: genetically modified mosquitoes that self-destruct before doing any damage. Brazil will probably be the first nation to approve large-scale releases of male mosquitoes with a lethal gene that causes their offspring to die before reaching adulthood, according to Hadyn Parry, chief executive officer of Oxitec Ltd., a U.K. biotechnology company that has developed the technology. “I’m hopeful it...