Old tires, a new weapon against Zika

With Zika virus reaching epidemic levels throughout South and Central America, southern Mexico and the Caribbean, a team of innovators has taken some old tires and turned them into a potential weapon against the deadly disease.

With Canadian Government funding, the team from Canada and Mexico successfully tested the low cost, environmentally-friendly way of destroying the eggs of the mosquito genus that spreads dengue and likely spreading the Zika virus.

The study, conducted in a remote, urban area of Guatemala, documents a cheap, easy system to reduce virus-carrying Aedesgenus mosquitoes by capturing and destroying its eggs.

The system includes an innovative Canadian-designed trap called an "ovillanta," created from two 50 cm sections of an old car tire, fashioned into a mouth-like shape, with a fluid release valve at the bottom.

Inside the lower tire cavity, a milk-based, non-toxic solution developed at Sudbury's Laurentian University lures mosquitoes. Inserted to float in the artificial pond is a wooden or paper strip on which the female insect lays her eggs. The strip is removed twice weekly, analyzed for monitoring purposes, and the eggs destroyed using fire or ethanol.

The solution, which now includes mosquito pheromone, the female insect's chemical perfume that helps others identify a safe breeding site, is then drained, filtered and recycled back into the tire. The pheromone concentrates over time, making the ovillanta even more attractive for mosquitoes.

Researchers found the rubber ovillanta significantly more effective at attracting the Aedes mosquito than standard traps made from 1-litre buckets.

During the 10-month study, the team collected and destroyed over 18,100 Aedes eggs per month using 84 ovillantas in seven neighbourhoods of the town of Sayaxche (population 15,000), almost seven times the roughly 2,700 eggs collected monthly using 84 standard traps in the same study areas.

Targeting mosquito eggs using the ovillanta, researcher Gerardo Ulibarri of Laurentian University says, is one third as expensive as trying to destroy larvae in natural ponds and only 20 percent the cost of targeting adult insects with pesticides, which also harm bats, dragonflies and the mosquitoes' other natural predators.

Canada's Minister of International Development and La Francophonie, the Honourable Marie-Claude Bibeau said, "Innovation is a key driver underlying the Government of Canada's approach to international development. Innovative solutions that deliver improved global health outcomes, such as for the fight against the Zika virus, are needed."

The results appear in the journal F1000Research.