Before the Zika virus emerged as a major health crisis, mosquitoes have long been the deadliest creatures on the planet.
Estimates on the number of people who die from mosquito-borne diseases like malaria, dengue fever, West Nile virus and yellow fever range between 725 thousand to 1 million per year. As recent advances in methods of genetic engineering open up the possibility of eradicating mosquitoes from the face of the earth, are there compelling reasons why humans shouldn’t intentionally cause the extinction of the insect species? Especially given that out of 3,000 varieties of mosquitoes on earth, only about 200 of those bite humans.
How close are we to the ability to wipe mosquitos off the planet? Is isolated eradication of the varieties that carry deadly diseases a realistic option? What roles do mosquitos play in our ecosystems? How much of a threat is the Zika virus to Southern California?
Here are some important takeaways:
Larry Mantle: Could you possibly genetically modify genes in a way that would eradicate a type of mosquito?
Anthony A. James: On principle, yes it is. And in fact, there [has] been a couple of applications where people have developed systems that cause the mosquitoes to die when they get the genes that people have engineered.
Larry Mantle: Would there be an environmental harm in doing this? If you were to take away a particular type of mosquito, might that take away a food supply?
Anthony A. James: Well, let’s look at the example. For example, Southern California, where the two mosquitoes that are of interest here are Aedes aegypti and another one called Aedes albopictus. Aedes aegypti is actually native to Africa, the jungle reasons of Africa and Aedes albopictus comes out of Eastern Asia. Both of those are invasive species to southern California. So if we were to remove them from southern California we actually would not be doing any harm to the ecosystem here. In a sense, you could think we would be actually fixing it by removing them.
Larry Mantle:If [a] genetically modified mosquito is introduced with the impact of eradicating the other two species, is there a chance that then the genetically modified mosquito could live on and become an invasive species?
Anthony A. James: So, we would actually design it so that they don’t persist in nature. We would like to think of it as a fail-safe approach where you have the ones that you release are only good for one generation and pass their genes on to the wild mosquitoes and the next generation and they expire. So it would be something that would not be maintained in the population. We call that self-limiting.
Larry Mantle: What is the estimate of how many of the genetically modified mosquitoes you’d have to release into southern California to actually eradicate the species?
Anthony A. James: Well the good news –at this point— [is] not very many because we don’t have large numbers of these invasive mosquitoes yet. And so, I’m guessing it would be somewhere in the tens to maybe one hundred thousands-- depending upon the target area. But the thing that we’re really looking at is only releasing male mosquitoes, which don’t feed on people. So, we wouldn’t be putting females out that would be biting people as well.
Anthony A. James, professor of microbiology and molecular genetics at UC Irvine specializing in gene modification as a tool to combat mosquitoes that carry deadly diseases. He is currently working on a new plan to prevent the Zika virus from becoming a health threat in Southern California