A number of emerging tools can directly control vector organisms. For example, altering the gut microbiome of mosquitos or tsetse flies can make it impossible for them to host the parasites responsible for disease development in humans.17
Similarly, genetically modified Aedes aegypti mosquitoes have been released in Florida, carrying a gene that kills females in the larval stage.18 The mosquitoes carry a range of diseases including Zika, but it is hoped that the female-lethal gene will spread and cause the population to dwindle, reducing transmission of the pathogens.19 Previously, trials have used mosquitoes infected with Wolbachia bacteria, which have successfully reduced the transmission of dengue.20
Alongside these control mechanisms, we need to develop indicators of ecological health that influence disease risk: essentially, early warning systems for outbreaks. A crucial step in devising such systems will be to integrate surveillance of human and animal diseases.21 At present these are monitored separately, often by distinct agencies.22
