Monday 23 November, 2020

Watch: Brazilian researchers develop new mosquito trap

Photo: iStock/Getty images.

Photo: iStock/Getty images.

Brazilian researchers have developed a new type of mosquito trap in a bid to prevent the spread of mosquito-borne diseases. 

Zika, chikungunya, dengue and yellow fever are all transmitted by Aedes Aegypti mosquitos and some predict that through global warming, mosquitos may expand their habitats to Europe and North America by the end of the century.


At Rio de Janeiro's Federal University, a professor of dentistry took up the task to find ways to prevent the Aedes mosquito from reaching his then small newborn child.

Ivo Carlos Correa uses many kinds of light in his work and he thought maybe light could provide the answer.

After some research, he found a study about the light sensitivity of the female of the Aedes Aegypti mosquito and he decided to manufacture a trap using the right combination of lights.

But first, he had to run tests to see if these light frequencies would be efficient attractors of the Aedes Aegypti.

At the Chemistry department of the same university, Professor Monica Ferreira Moreira is used to breeding mosquitoes for testing the effects of different substances on their biology.

Large numbers of mosquitoes were bred for the tests from larvae and placed into a special compartment where the experimental traps were tested.

Different colours of LED lights were used in the experiment. Green, blue and yellow were the main colours used in the tests.

The lights were tested on batches of 20 female mosquitoes at a time.

"Three experiments using the lesser intensity, three with medium intensity and three with strongest intensity using all the colours, yellow, blue and green. The results were very distinct in which the green catches nineteen mosquitoes the blue light catches 14 or 15 and the blue light a little more, 15 or 16," Dr Correa said.

Once the results were ready, Dr Correa mounted 20 experimental traps which were also tested at the chemistry lab.

The group applied for a world patent which has been accepted and is negotiating with local industries for the production of the new mosquito trap.

At his home, Dr. Correa showed the new traps which use blue and ultraviolet light to attract mosquitos, but can also attract other types of insects.

"This is a trap that attracts all kinds of insects, like this other one and this one too. So these are not specific traps, they can attract bees, flies, stink bugs, all kinds of insects besides the Aedes," said Professor Correa.

He himself uses the trap at home where his concerns with children's health stimulated his research.

"I cannot conceive of these children getting chikungunya, zika or even dengue, haemorrhagic dengue. We are very afraid," says Dr Correa's wife.

The trap has also been tested in neighbourhoods with high rates of arbovirus infestations.

At the home of Maria Guiomar Lopes, her mother contracted the feared chikungunya fever as did many in the neighbourhood.

Lopes is also a professor at the faculty of dentistry and is satisfied with the results using the trap invented by his colleagues.

"I didn't get chikungunya. My father didn't either but my mother and my daughter and many of the neighbours here in the street had it. I didn't get it and I think it's effective," says Lopes about the trap.

Many of her neighbours here are expecting the beginning of commercial production of the provisionally named 'Zika Trap' to prevent the spread of these diseases.

In Rio de Janeiro and other cities, public health clinics receive a large number of patients afflicted by these diseases.

Yellow fever was eradicated through vaccination, however, dengue fever registered a seven-fold increase in the first semester of 2019 with 1.1 million suspected cases and 388 deaths, a 163% increase compared to the same period last year.

"Dengue, Chikungunya and Zika, they are three arbovirus diseases. A fourth one is arriving but in principle, it's those three," says Dr Garcia Vergara.

Dr. Garcia Vergara checks all patients for joint symptoms which might indicate chikungunya, a crippling disease causing extreme joint pain that can last for months and impede work.

For health professionals, however, there is little hope these diseases will subside.

"That mosquito has many ways to hide and reproduce. As long as the mosquito focal points are not neutralised within the ecosystem, it will continue to exist," said Dr. Garcia Vergara.

Cases of dengue fever and other mosquito-borne diseases are seen here on a daily basis, she said.

"Brazil and Rio de Janeiro have been trying to control the Aedes Aegypti, which is not an easy task as they reproduce even on water inside a soda cap," says Cristina Lemos, Rio's superintendent of public health surveillance.

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