The Anguillian newspaper caught up with Mr. Walter Tabachnick during a brief orientation and welcome back meeting at the Water Laboratory on Monday 18th April.
Mr. Tabachnick, who is a professor at the University of Florida, previously visited Anguilla over three decades ago when he conducted a study of the Aedes Aegypti Mosquito species on Anguilla. The study, a collaborative effort between the University of California and Yale University, focused on the unique situation on the island when there were Aedes Aegypti developing in the rock holes in the limestone around the island. Mr. Tabachnick worked with then, Supervisor and Manager of the Solid Waste component of the Environmental Health Unit, Mr. Leroy ‘Brother Lee’ Richardson.
A paper was subsequently published in December 1990 entitled “Genetic Analysis of Rock Hole and Domestic Aedes Aegypti on the Caribbean Island of Anguilla”. In that paper it was noted that with the technologies used at the time, genetic differences were detected. Mr. Tabachnick described the technology used then as old and he is optimistic about this new study.
On his most recent trip to Anguilla, Mr. Tabachnick stated: “My colleagues and I have long wondered about the ecology of the Aegypti situation on Anguilla that could add understanding of the Aedes Aegypti capability for non-domestic behaviour that could develop in other locations under the right conditions”. Mr. Tabachnick is collaborating with a group at Yale University on this project. He stated: “We’re looking at the DNA of the mosquitoes in homes versus the mosquitoes in the rock holes to see how different they are”.
The project, ‘The Genetic Variation of Anguillian Mosquitoes’, is a subset in a worldwide study on the Aedes Aegypti Mosquitoes. When asked about the aim of the study in Anguilla he said: “The end product is going to tell us information about the extent as to why these mosquitoes develop in this way, and will lead us into understanding other areas of the world where the same type of development could occur. It’s going to tell us how this mosquito will respond and react in different environments”. He noted that since his initial studies there have been new developments in technical capabilities that would serve to provide more information on this follow up study on Anguilla.
Mr. Leroy Richardson, who recently celebrated his retirement from the Public Service, also gave some insight into the previous project. He said: “The study was difficult because at the time Anguillians were indirectly feeding the mosquitoes through goats and cows that would be around the rock holes which provide a good source of water for the animals. When the animals are around then the mosquitoes can then get a good meal”. It was also stated that there is still uncertainty of where the rock hole mosquitoes originate from and there is hope this new study will be able to decipher that. Mr. Tabachnick observed: “For the rest of the world, what this leads us to – does every Aedes Aegypti Mosquito have in them some mosquitoes that could go to somewhere like these rock hole habitats, or is this unique to the type of population in Anguilla. How much of a concern, we don’t know”.
For this study the new technology to be used will be looking directly at the Deoxyribonucleic Acid (DNA) of the mosquitoes, whereas, in previous studies they looked at the proteins. Now the mosquitoes do not need to be alive, and even a leg can be enough, unlike the previous study where they had to be alive. Mr. Tabachnick said: “I could have only looked at a few proteins in each individual, whereas, now we can look at literally thousands of different genes in an individual mosquito and compare one mosquito to other. We can then compare the mosquitoes to see if they carry genes from one location to mosquitoes in a next”. He noted that this is the most precise their capabilities have ever been. In commenting on the wider scope of the project, he said: “This is part of a bigger project which is looking at Aedes Aegypti around the world, so Anguilla would be integrated showing how Anguilla’s mosquitoes fit in with those in the entire Caribbean Region and then how does that fit in with the rest of the world”. He also said that part of the study is to understand how the mosquitoes migrate, their origin and how effective control techniques work on a macro level.
In lauding the work of Anguilla’s Vector Control unit Mr. Tabachnick stated that his work would have been made difficult was it not for the Unit and people like Mr. Richardson. He went on: “[The aim is] to re-establish that connection with the Anguilla Vector Control Unit such that they can, as part of their routine surveillance for Aedes Aegypti, start collecting and sending us some material… just the way Mr. Richardson did it 30 years ago”.
The bulk of the work of the worldwide project is being carried out by the Yale team. Mr. Tabachnick is in Anguilla because of his own interest in Anguilla as well as his previous experience here.
