4) This Is How To Stop The Zika Virus
MIT Technology Review, 29 January 2016

Michael Reilly

The Zika virus is out of control. Earlier this week, the World Health Organization called it an “explosive” epidemic, and officials in Brazil, the country hardest hit by the disease, have admitted that they are “losing badly” to the disease. Brazilian president Dilma Rousseff went so far as to declare war on Aedes aegypti, the mosquito that transmits Zika. Officials in several other countries in the region have asked women to consider not getting pregnant until the epidemic is brought under control.

The good news is this: we know how to fight mosquitoes, and our arsenal is growing bigger by the day. In her declaration, Rousseff said she will dispatch over 200,000 troops throughout Brazil to enact tried and tested methods of combatting mosquito populations. That includes spraying insecticides, eliminating pools of standing water, and educating the public. These methods work: in 1942 Brazil undertook a campaign to eradicate A. aegypti across the country, largely in response to yellow fever. Countries throughout South America, Central America, and the Caribbean joined in, as did the Rockefeller Foundation in the U.S., and by 1962 Brazil and 17 other countries were free of the mosquitoes.

But such methods also take time, and time is not on our side for fighting a disease that has spread as far as it has despite only arriving in the Western hemisphere in 2014. As the situation worsens, several technological approaches may start to look appealing.

The first is rather mundane: cell phones. Cell phones are useful because they record the movements of their owners. That data can be used to track disease hot spots and predict where they may flare up next. The technique has already been employed in Africa in the battle against malaria and in Pakistan against dengue fever—both mosquito-borne diseases like Zika.

Genetically modified mosquitoes could also have a role to play. Successful tests in the Cayman Islands and Brazil have shown that the introduction of modified male mosquitoes can cause local populations to crash. But these tests, conducted by the British firm Oxitec, have so far been on the scale of a few neighborhoods. Ramping up the process to cover all of Brazil would require a huge logistical effort to grow and distribute the modified insects.

Then there is the gene drive. This newly developed technology involves inserting genes into an organism in such a way that a trait spreads throughout a whole population. In theory, a gene drive could be created that prevents mosquitoes from incubating Zika virus—or destroys the entire species of A. aegypti. A gene drive has been created that prevents mosquitoes from harboring the malaria parasite. But some researchers are understandably concerned about intentionally messing with natural selection. Once a drive is released into a wild population, there is no turning back, and there is no telling what sort of side effects it might have.

Ultimately, it is unlikely that any one method will stop Zika in its tracks. Winning this war is possible—it has been done before. But it will take an effort the likes of which we have not seen for almost half a century, and perhaps some brand-new technology.

5) In The Wake Of The Zika Virus, Should Humans Try To Eradicate Mosquitoes?
Atlas Obscura, 31 January 2016

Jessie Guy-Ryan

A worker sprays DDT directly into a water supply during the National Malaria Eradication Program. (Photo: CDC Public Health Image Library, ID#4684)

Mosquitoes might just be the most unpopular insect on Earth. At their most harmless, they cause infuriatingly itchy welts, ruining barbecues and birthday parties around the globe. At their worst, they’re vectors for serious diseases like malaria, Dengue fever, West Nile virus, and the Zika virus, which experts now think may be a bigger threat to global health than the recent Ebola epidemic.

The threat is so severe that some, such as Wellcome Trust head of infection and immunobiology Mike Turner, are advocating the use of DDT—long banned in the United States and elsewhere due to its environmental and health risks—to eliminate the mosquito species’ that serve as carriers of the virus.

This weekend, a few pundits have taken things one step further by calling for the eradication of all mosquitoes.

Purposefully eradicating an entire species sounds outrageous, but we already use a variety of strategies to control mosquito population growth. Famously, in 1947, the U.S. carried out the National Malaria Eradication Program, blanketing the southeast in DDT and eradicating malaria in the U.S. in just four years.

Today, New Yorkers and other urbanites are likely familiar with local pesticide-spraying events to combat the spread of West Nile virus and other mosquito-borne illnesses. And looking forward, many scientists are moving beyond pesticide and looking to genetically modify mosquitoes to control—or even eliminate—certain populations. The modifications come in a variety of flavors; one team modified mosquitoes’ smell receptors, eliminating their ability to smell nearby humans.

Professor Anthony James and colleagues at UC Irvine modified Aedes aegypti so that female mosquitoes were born without wings, crippling their ability to survive and reproduce. Right now, mosquitoes possessing a lethal gene that prevents them from reaching adulthood are being released in Brazil to reduce mosquito numbers and, hopefully, control the spread of the Zika virus.

Humans have shown an aptitude for unwittingly driving other species to extinction, but should we really turn our talents towards purposeful eradication? Some scientists have argued that the consequences of allowing mosquitoes to live outweigh any dangers posed by removing them from the ecosystem. Carlos Brisola Marcondes, a medical entomologist, tells Nature unequivocally that a world without mosquitoes would be “more secure for us,” and biologist Olivia Judson argued in theNew York Times that other insects could easily replace mosquitoes’ role in any ecological niche. But each of these arguments have a counter—entomologist Phil Lounibus points out that whatever replaces the mosquito could be “equally, or more, undesirable from a public health viewpoint”.

Even if the idea seems sound from a biological perspective, many are ethically squeamish about purposefully eliminating another species. That might be why some scientists have focused on less murderous ways to lessen the health impacts of mosquitoes. The Kew Royal Botanical Gardens is working on a project to track harmful mosquitoes with acoustic devices, and James has moved on from removing wings to genetically modifying mosquitoes so they can’t spread disease.

Regardless of whether you think mosquitoes should be driven from the Earth, or simply made a little less dangerous, large-scale implementation of these strategies is probably a long way off; but the next time you find yourself scratching, take comfort in the fact that future could hold a mosquito-free world.