Brazil Uses Biotechnology to Take the Sting out of Dengue Fever
Jul 03, 2014
Richard Dijkstra: Ponta Grossa, Parana, Brazil
All eyes are on the World Cup in Brazil this month. As a farmer in southern Brazil in Parana State, near the city of Ponta Grossa, I’m cheering for the home team—and I’m relieved that we survived a tough contest against Chile in the first game of the knockout round.
Another kind of knockout is also on my mind, and our rival is one that many Brazilians know far too well: mosquitoes. These pests are constant threats to public health—but now biotechnology may offer an excellent solution to an age-old problem.
Mosquitoes spread many diseases, and one of the worst is dengue fever. In addition to elevating temperatures, the virus causes headaches, joint pains, and skin rashes. It affects about 50 million people around the globe each year. Perhaps a million of them die. There is no vaccine or cure.
My region of Brazil is too cold at night for the mosquitoes that spread dengue fever to survive, but I have friends who have suffered from the affliction. They’ve struggled with severe discomfort—they complain about bad pain behind their eyeballs—and they must worry about second infections, because those are the ones that can turn fatal.
Biologists have identified more than 3,500 species of mosquito around the world, but only a handful of them carry the virus that causes dengue fever—and one in particular, the Aedes aegypti, is the main culprit. It has African origins but now lives in tropical areas just about everywhere, including three Brazilian cities that are hosting World Cup games.
Unfortunately, these pests are difficult to control. Bed nets provide good protection against mosquitoes that come out at night, but dengue-carrying mosquitoes are active during the day. They also thrive in urban areas, so it’s impossible for many people to avoid their habitat. Finally, these parasites have started to develop resistance to common forms of insecticide.
For a while, it looked like the best we could do was simply to put up with a certain amount of dengue fever.
Today, however, biotechnology offers new hope and a sustainable way to confront the problem. British scientists have learned how to fight back through genetic modification. The transgenic mosquito carries a gene that prevents the females from flying when they reach adulthood. Males can still fly but that does not cause a problem because they feed only on nectar and plant juices, unable to transmit the disease. As the mosquitoes reach adulthood and males mate with females, the gene will be transmitted to their offspring ultimately helping to solve a public health problem.
Field trials last year in the city of Jacobina showed promising results, with Aedes aegypti populations crashing by an estimated 79 percent. This year, Brazilian officials have launched a pilot program to test the method in larger areas. They’ve worked hard to engage the public, holding meetings to explain the approach and advertising it on the sides of trucks as well as on the radio. In April, a report on Public Radio International noted the program’s "wide acceptance" among the people of Jacobina.
And why wouldn’t they approve? It’s a creative solution that may prevent a terrible public health malady.
It’s environmentally friendly, too. Right now, the best way to slow down the transmission of dengue fever is to spray insecticide around vulnerable homes. Yet this treatment kills insects without discrimination—not just Aedes aegypti, but also bugs that pose no threat to anyone.
Biotechnology lets us focus on the true problem. In military terms, we’d call it a surgical strike that hits its target as opposed to a carpet bombing with collateral damage.
It remains to be seen how well this strategy will work. Brazil is a huge country, full of mosquitoes. Reducing their numbers is no simple trick. Yet even a small cut in the incidence of dengue fever will improve the lives of my fellow Brazilians.
We have every reason to be optimistic. On my own farm, I’ve seen how biotechnology can help me grow more food on less land. Adapting the gene-transfer technologies that have improved agriculture to other challenges could represent a major step in the global Gene Revolution.
I’m cheering for Brazil not only to win the World Cup, but also to triumph over dengue fever.
Richard Franke Dijkstra farms with his family in Southern Brazil where they grow soybeans, edible beans, corn, wheat, barley, ray grass and black oats; 50% of the soybeans and corn they plant are GM and 100% of the operation is no-tillage. Richard and his brother-in-law also operate a 480 cow dairy and raise 4000 hogs annually. Richard is a member of the Truth About Trade & Technology Global Farmer Network (www.truthabouttrade.org).
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