Climate change drives dengue in France

Subject :Environment

Impact of climate change on Dengue-

Dengue-endemic countries will see increased dengue cases through faster viral amplification, and increased vector survival, reproduction and biting rates.
Longer period of spread
Increased temperature will allow vector and virus to spread to countries that are currently free of Dengue

Case of France and other countries-

France has recorded highest number of Dengue cases this year since 2006.
And for the first time in Europe, one event causing 34 cases on a single day was recorded in France on October 21, 2022.
Aedes albopictusis is the vector responsible for virus spread in France.
Aedes aegyptiis’s (Vector of dengue in tropical countries) eggs are unable to survive the cold winter in Europe.
Aedes-borne virus transmission locally is expected in southern France due to colonisation of A. Albopictus.
The serotype 3 (DENV-3) has been identified for the first time this year in France.

Why Dengue spread in temperate countries-

Environmental conditions have a major impact on the efficiency of the vector system as well as on vector density and host-vector contacts.
Southern France and Mediterranean have been at risk of dengue since the early 2000s when the Asian tiger mosquito (Aedes albopictus) arrived, then spread through Europe.
The dengue season in Europe is only increasing each year with climate change.
Vietnam and the Philippines reported over 3,00,000 cases.

Dengue-

Dengue is a mosquito-borne tropical disease caused by the dengue virus (Genus Flavivirus), transmitted by several species of mosquito within the genus Aedes, principally Aedes aegypti.
This mosquito also transmits chikungunya, yellow fever and Zika infection.
There are 4 distinct, but closely related, serotypes (separate groups within a species of microorganisms that all share a similar characteristic) of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4).

Controlling dengue using bacteria-

Recently researchers from the World Mosquito Program have used mosquitoes infected with Wolbachia bacteria to successfully control dengue in Indonesia.

Dengue vaccine-

The dengue vaccine CYD-TDV or Dengvaxia was approved by the US Food & Drug Administration in 2019, the first dengue vaccine to get the regulatory nod in the US.
Dengvaxia is basically a live, attenuated dengue virus which has to be administered in people of ages 9 to 16 who have laboratory-confirmed previous dengue infection and who live in endemic areas.