Mutated mosquito variety behind spread of dengue in Odisha, say RMRC scientists

BHUBANESWAR: In a major revelation, a team of scientists at the Regional Medical Research Centre (RMRC), Bhubaneswar, has found a variety of Aedes mosquito called Albopictus, which is the reason behind widespread dengue cases in the city and the state this year.

The scientists found that Albopictus, one of the three varieties of Aedes mosquito, was not carrying the infection earlier, but due to mutation, this variety of Aedes has started carrying the vector this year.

Earlier, only the Aegypti variety of Aedes was spreading dengue. "Our study found that a genetic mutation has taken place between the varieties of mosquitoes. Along with Aegypti, Albopictus bite are also infecting a person with dengue," said senior scientist Mahesh Chandra Sahu.

Sahu said the concentration of Albopictus in the meantime is 90 times higher than that of the Aegypti variety in any particular area in Odisha. "If we find 10 to 20 Aegypti in a particular location, we will find 100 to 150 Albopictus in the same region," he said.

The scientist attributed this particular phenomenon to be the reason behind high number of dengue positive cases in the city and the state at large this time. For instance, earlier only 10 mosquitoes were causing dengue, now the number has risen to 150. The cases will automatically increase, he said.

Sahu's team has further done serotyping of dengue this time and has also discovered that the DENV I type of antigen is causing the infection more in people than the other three types, particularly in Bhubaneswar and surroundings.

"There are four serotypes of dengue found in the state. Our study established that DENV II was more prevalent last year but this time it is DENV I, which is spreading more. It is mainly because the anti-body has already developed among the people for the DENV II," he said.

About the prevention measures, Sahu suggested that the local administration should implement a lockdown kind of scenario in the hotspot zones and carry out intensified fogging, which will definitely help in containing the spread of the disease.

The identified hotspots and its surrounding area must have intensified fogging. The oil and solution used in the fogging also needs to be checked and changed in volume and variety. This way we can make the city free of dengue, the scientist suggests.