Canadian researchers make Tyres that can ward of Zika virus


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Zika virus disease is caused by a virus transmitted primarily by Aedesmosquitoes where People with Zika virus disease can have symptoms that can include mild fever, skin rash, conjunctivitis, muscle and joint pain, malaise or headache. These symptoms normally last for 2-7 days and the best form of prevention is protection against mosquito bites.

Canadian researchers have developed a cheap, effective and non-toxic way to dramatically reduce disease-carrying mosquito populations by using a ubiquitous item that, ironically enough, the pests love to breed in: old tyres.

Dr. Gerardo Ulibarri, PhD, an associate professor of medicinal chemistry and eco-health at Laurentian University in Sudbury, Ontario was the one to develop the device, known as an ovillanta to destroy the larvae of the Aedes, a mosquito that carries the Zika virus as well as the dengue, chikungunya and yellow fever viruses.

The ovillanta offers a win-win-win situation in the war against these diseases, which together afflict millions of people annually primarily in tropical countries and result in tens of thousands of fatalities, according to data from the World Health Organization.

For starters, the devices eliminate the need to use pesticides that can damage the environment and carry the risk of collateral damage to other insects  including those that eat mosquitoes. Furthermore, subsequent generations of mosquitoes can build up resistance to pesticides, making them less and less effective, Ulibarri notes.

The devices also provide an answer albeit a small one for one of the world’s most intractable waste-disposal problems: What to do with old tyres. Moreover, the traps are inexpensive and relatively easy to make, and the there’s an almost inexhaustible supply of materials available .

Researchers found that 84 ovillantas placed in seven neighborhoods in the town of Sayaxche destroyed more than 18,000 Aedes larvae per month. That’s nearly seven times better than standard traps.

And equally as noteworthy, no new cases of dengue were reported in the area during that period; typically, about two to three dozen cases would occur during that time, Ulibarri says.

The ovillanta, which consists of two roughly 20-inch-long pieces of tyre and a tube drain valve, mimics “Mosquitoes will not lay eggs on a dry surface – they need moisture to hatch.

The water in the device must be drained about twice a week into a receptacle covered with a filter; something as simple as a piece of white cloth works well because the color makes the larvae clearly visible, he notes.

After that, users destroy the eggs, pour the water back into the ovillanta (topping it off with fresh water) and install two new landing strips. It’s important to recycle the water because after the eggs hatch, they release a pheromone into the water that tells other mosquitoes it’s a good, safe place to lay eggs.

It usually takes about one month – the average life cycle of a female Aedesin hot weather – before the traps start making a dent in local mosquito populations.


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