Too smart to smash! - Dengue-spreading mosquitoes finding ways to block chemicals designed to kill them
Published:Sunday | January 27, 2019 | 12:00 AM
University of the West Indies (UWI) professor, Dr Rupika Delgoda, has conceded that the Aedes aegypti mosquito, which spread dengue fever and other diseases, has been proving a challenge to some of Jamaica’s brightest minds who have been working to contain it.
But Delgoda is confident that the consortium, which has been working assiduously to devise strategies to curb diseases caused by this mosquito, will record success.
More than 12 experts have already joined the UWI Mosquito Research team, which was formed two years ago during the outbreak of Zika, which is also spread by the mosquito.
“The idea was to bring the researchers from the UWI into a forum where the Ministry of Health can interact with them,” said Dr Delgoda.
She noted that research is important for the shaping of policies to address mosquito-borne diseases.
Among those in the mosquito research consortium is Charles Grant, an international atomic energy expert who is the director general of the International Centre for Environmental and Nuclear Sciences at UWI, biochemist Dr Lisa Lindo, head of the Mona School of Engineering Dr Paul Aiken, and several senior lecturers and research fellows spanning different departments.
Senior lecturer at the Caribbean Institute for Health Research, Dr Georgiana Gordon-Strachan, said she is particularly focused on assessing how climate change contributes to the spread of vector-borne diseases such as dengue fever.
“As we all know in Jamaica, when it rains, our mosquito population tends to increase, so even without doing any type of scientific studies, our experience tells us that once we have intense rain, then we have an increase in the number of mosquitoes that are around,” said Dr Gordon-Strachan.
The institute has been using a mathematical model to predict when there might be an outbreak of vector-borne disease, so that preventive measures can be heightened during these periods, and Dr Gordon-Strachan said they have been mapping data going back to 1987 at least.
“It is quite smart, it is surviving, and that is its role, to try to survive,” Dr Gordon-Strachan said of the Aedes aegypti mosquito.
She added the creation of the consortium of researchers is a good move.
“We are trying to pull researchers from many different groups to tackle the one problem, because as you can see, it has many different components. There is the scientific component with the lab and the mosquito itself, there is the social component which has to do with behaviour, and there are other components as well,” said Dr Gordon-Strachan.
Studies undertaken by members of the consortium have already unearthed some useful findings.
Dr Sheena Francis, a research associate at the Natural Product Institute at UWI, has found, for example, that the Aedes aegypti mosquitoes in St Andrew have grown resistant to insecticides.
The study was funded under the Zika AIRS Project (ZAP) and plans are under way to replicate this study islandwide.
Visiting households
The Mosquito Control Research Unit at UWI is also funded by ZAP and other partners. In addition to conducting laboratory work, field officers have also been visiting households to educate individuals and distribute larvicide, which is a chemical used for killing the mosquito larvae.
“As householders, we have to be vigilant about water storage and how we dispose of our garbage. Things like those we can actually do as people to try and curb or decrease their breathing ground,” said Dr Francis.
Given the absence of a vaccine to protect against vector-borne diseases such as dengue, Dr Delgoda believes behaviour change is perhaps the best way to counteract the deadly attacks from the Aedes aegypti mosquito.
“These tropical neglected diseases are not in the forefront of the research agenda,” said Dr Delgoda, who noted that vaccines are mostly developed for diseases that affect more developed countries.
“We do what we can do,” added Dr Delgoda, who has found that the Aedes aegypti mosquito is increasingly finding ways to block the chemicals meant to kill it.
“It is constantly exposed to this chemical and realises that it is killing it, and over time has developed a mechanism of getting rid of it as soon as it comes. It metabolises it, turns it into something that is not toxic and out it goes, so the mosquito thrives,” said Dr Delgoda.
As director of the Natural Products Institute, Dr Delgoda’s focus is now on finding natural products that can be used, along with insecticides, to boost effectiveness.
“It is constantly exposed to this chemical and realises that it is killing it and overtime has developed a mechanism of getting rid of it as soon as it comes.”