Insecticides May Cause Higher Resistance in Mosquitoes

Insecticides, while effective in the short-term, may result in higher resistance in mosquitoes, leading to worse epidemics in the future, according to a study released Tuesday.

The current approach has proven to be inadequate to wipe out the mosquitoes that cause dengue infections, reports the AFP.

Using insecticides, which target only mosquito larvae, and not adults, could result in higher resistance in the insects.

The study found it could lead to less disease immunity among humans, especially in urban settings.

Dengue is a mosquito-borne infection that causes severe, flu-like symptoms in some 50 million people every year, mainly in developing countries.

The disease is rarely fatal but frequently debilitating, and global incidence of the disease has risen dramatically in recent decades.

The increase has been linked to both rapid urbanization and the impact of global warming. Some 2.5 billion people are at risk, reports the AFP.

No treatment, cure or vaccine currently exists — the only way to control the disease is to kill the mosquitoes that carry it, especially one species: Aedes aegypti.

According to the study, the method prevailing in most countries — attempting to destroy breeding areas — is misguided, reports the AFP.

“Year-round larval control can be counterproductive, exacerbating epidemics in later years because of evolution of insecticide resistance and lost of herd immunity,” the researchers said.

“Herd immunity” is the term scientists use to describe immunity that occurs when enough of the population is inoculated from having had the disease to prevent it from spreading easily. source