Recent spike in chikungunya cases forces me to return to my pet subject of mosquitoes, as this could be harbinger of some real bad news heading our way. It is likely that the existing big three of our region; anopheles, Aedes aegypti and culex are now joined by a tiger with even greater biting power.
Aedes albopictus, Asian tiger mosquito, could to be finding a foothold in our city that is already mauled badly by vector-borne diseases. There is great reason to worry, as it is better suited to carry chikungunya, hardier than Aedes aegypti, making it one of the most invasive species of the world.
Starting from forests of East Asia, it is now resident of every continent other than Antarctica. It should feel at home amongst Gujaratis, as once it reaches a new country, it always settles down and sets its shop alongside its long lost cousin Aedes aegypti!
The story of Aedes cousins is worth knowing as it tells us about the power of the book of life and why a.albopictus needs to be feared more.
The Aedis cousins tormenting us come from two far apart regions of Earth. Aegypti is from Africa while albopictus hails from Far East, but genetics tell us that they shared a common ancestor about 70 million years back. Just to get a perspective on the antiquity of their relationship, we are barely half a million old race that started building homes just couple of thousand years back.
As both these mosquitoes have taken human habitat like a duck takes to water, it is clear that there existed a latent talent both had discovered millions of years ago that they could put to use to exploit the new environment, and this is their ability to thrive with very little amount of water. The fact that both cousins are still able to use it today is because once an adaptation is made, it is logged into the great book of life which is written using DNA code available for use till the species continue to survive.
The most interesting part of genetic information is; it is like a book with many pages passed over generations, but it is not always read entirely. The being that beholds the book can have many adaptations that are not expressed or used, but they can still be hidden in the book, even for millions of years, available to be read when needed. It is this quality of the book of life that makes A. albopictus a subject of great worry.
As we can now quantify creatures based on the amount of DNA data they carry, A. albopictus shows that it is carrying nearly 1976 MB data, which is the largest mosquito genome sequenced till date. If we look closely at its genome, it comprises of a numbers of gene family members involved in insecticide resistance, diapause, immunity, and olfaction. Armed with this large genome repertory and plasticity it has potential to exploit our mosquito-friendly city even better than other three species.
If A.albopictus is here, it is here to stay, so we need to seriously focus on this new threat, or the future looks bleaker than ever before. The only and only option for us is research. We need to know our enemy and we need to know it before it can hit us heard.
I again plead to AMC and health department of Gujarat to seriously consider setting up a dedicated research center for vector-borne diseases urgently. In fact, this is the time of the year to start the study so we are ready and armed when the peak season of vector-borne diseases hits us.