April 15, 2013, 4:06 p.m.
We flail, we swat, we sweat. We spray, cover up, and hide. But still the tiny, fearsome mosquito penetrates our best defenses. ZAPPED: the buzz about mosquitoes is the story of our ongoing struggle to conquer a little insect that is both delicate and deadly. As the program reveals, this beautiful and versatile blood-sucker has always managed to stay one step ahead of us.
As tortured as we are Zapped uncovers, in exquisite detail, how the mosquito goes about its handiwork. It’s really only the females that are the problem – they need our blood to incubate their eggs. And, out of more than 3500 species, only 200 or so transmit disease.
One of the most obvious questions for researchers is, why bite this person and not that person? Scientists know that part of the answer lies with our body odour. Certain compounds in our individual scent might attract - or repel - a mosquito.
Once the mosquito decides who smells the best, she alights and might probe as many as twenty times before biting. When she does, she injects an anti-coagulant and anesthetic through one tube in her proboscis, at the same time as she sucks up blood through another tube. As Zapped reveals, that’s where the danger lies: every time she sucks blood, she can also transmit pathogens that can make us very sick, or even kill us.
In Canada, Culex mosquitoes are the most dangerous because they transmit the West Nile virus. The biggest challenges come from the Anopheles and Aedesmosquitoes that spread the malaria parasite and viruses such as Dengue in Africa and South Asia.
Is the answer as simple as sleeping with a bed net, or putting screens on all doors and windows? In West Africa, such barriers are reducing the rate of malaria, especially in children. Or, does preventing the spread of disease require more sophistication? A genetically engineered mosquito that will not carry or transmit malaria and dengue fever – but that might deliver unintended consequences – is on the horizon.
From Victoria to Winnipeg, from Dhaka to London, we discover that globalization, rapid urban growth, and changes to the world’s climate have brought changes to the life of even the tiny mosquito. Indeed, they are a global phenomenon, thriving everywhere except Antarctica. They have persisted on the earth since the time of the dinosaurs. Do we have any chance of outsmarting this survivor?
ZAPPED: The Buzz about Mosquitoes is directed by Alan Burke, written by Jean Burke, and produced by Alan and Jean Burke in association with CBC, The Nature of Things.