Local trials have already seen a 90 percent reduction in aegypti numbers, according to the biotech company that developed the mutant gene. Critics have raised a number of objections, however, including the fact that other mosquito species also carry dengue fever, so the potentially fatal disease won't necessarily be eradicated by this risky approach. Others have pointed out that there have only been very small trials so far, so we don't know what happens if GM females, rather than males, are accidentally released into the wild (potentially causing allergic reactions in bite victims), or if some mosquitoes somehow inherit the modified gene but don't die from it. Either way, if Mother Nature does have some sort of retribution in store, then Brazil is about to find out.

[Image credit: Centers for Disease Control and Prevention]