Mosquitos spread dengue, chikungunya, Zika, yellow fever which may cause death if left untreated.

Axar.az reports citing AA that Asian tiger mosquitos which can transmit more than 20 fatal viruses are giving many European nations a health nightmare, experts said.

"For countries like Italy, France and Spain, this is already a very bad scenario. They cannot eliminate the Asian tiger mosquito anymore, they just try to reduce mosquito numbers and minimize effects," Soeren Metelmann, an academic at U.K.-based University of Liverpool said in an email interview.

"The Asian tiger mosquito can transmit more than 20 different viruses such as dengue, chikungunya, Zika, yellow fever and also some of the filarial worms, such as the dog heartworm," he said.

He explained the three stages through which a mosquito-borne infection is transmitted.

"This species has the advantage that it can lay special eggs at the end of the year that can simply wait until the winter is over and then the larvae hatch when temperatures are more suitable in spring," he said.

He predicted that a looming climate crisis leading to warmer temperatures could play a role in spreading mosquito-borne infections.