When Mosquitoes Were Killers in America
WouterUntil the 1950s, malaria was a killer in America. The disease, which causes a fever, jaundice and liver damage, was probably transmitted by the slave trade. Slave traders brought mosquitoes to tropical regions, where they would lay eggs in pools of water in trees and rocks.
The parasite that makes malaria infectious is found in the Anopheles mosquito’s gut. After it infects the mosquito, it spreads to humans. The most lethal type of malaria is Plasmodium falciparum. It kills about 400,000 people in sub-Saharan Africa each year.
Malaria is now on the global health agenda, and scientists are looking for clues to eradicate it. In the past two decades, malaria deaths have decreased by half. But scientists are concerned that the disease will continue to expand worldwide.
Today, more than half of the world’s population lives in areas where malaria is a risk. There are more than 2,500 species of mosquitoes, each carrying the potential to transmit diseases to humans.
As the climate has gotten colder, mosquitoes have adapted to breed more quickly. As a result, the season for mosquitoes is shorter in colder regions.
There are many different types of mosquitoes, including the Aedes aegypti, which is the carrier of Zika virus. The Aedes aegypti has adapted to follow people indoors, where it feeds on human blood.
Genetically modified mosquitoes were designed to eliminate the Aedes aegypti, but some residents of Florida Keys, where the method was tested, rejected them.
