Of all the mosquito species that populate the planet, few have proved themselves more resilient or more deadly to humans than the Aedes aegypti. The epidemics fueled by this tiny mosquito stretch across hundreds of years and include millions of victims.<\/span><\/p>\n Yellow fever, dengue fever, chikungunya. And now Zika, which has spread to more than 50 countries and can cause an array of severe birth defects.<\/span><\/p>\n \u201cOne of the most efficient killers in the world,\u201d Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told The Washington Post this year in discussing A. aegypti.<\/span><\/p>\n These days, travel, global commerce and a warming planet only seem to be helping the mosquito to again flourish after widespread eradication efforts in the first half of the 20th century. That could mean more outbreaks of more diseases in more places.<\/span><\/p>\n Writing Thursday in the journal Science, Yale University’s Jeffrey R. Powell, a professor of ecology and evolutionary biology, detailed how this species now breeds year-round in locations where it once didn’t exist \u2014 including in the District and California.<\/span><\/p>\n \u201cThese expansions are putting at risk large human populations that never experienced aegypti-borne viruses and therefore have no immune defenses against them,\u201d he wrote. \u201cThis greatly increases the likelihood of severe epidemics.\u201d<\/span><\/p>\n Powell noted that researchers have documented two subspecies of A. aegypti \u2014 the human-loving \u201cAaf\u201d and the \u201cAaf\u201d form traditionally found in forests \u2014 interbreeding in certain parts of the world from Argentina to Africa. \u201cThe consequences of increasing hybridization between the two subspecies remain unclear,\u201d he continued, although warning that it could lead to increased genetic variation and still more spread of disease.<\/span><\/p>\n Part of what has made A. aegypti such a formidable foe and such an efficient disease transmitter is its ability to adapt. It has evolved to thrive in the densely populated places, particularly urban environments littered with old tires, trash and other open containers. It can breed in spots as tiny as a bottle cap. Its larvae don\u2019t necessarily need water to survive, and eggs can lie dormant for a year or more \u2014 only to hatch once submerged in water. The sticky eggs glue themselves to containers as common and varied as the insides of old tires and the edges of birdbaths.<\/span><\/p>\n \u201cIt\u2019s one of those pests, like cockroaches, that has evolved over the last 15,000 years to exploit changes in human behavior and habitation,\u201d Ronald Rosenberg, acting director for the Division of Vector-Borne Diseases at the Centers for Disease Control and Prevention, said at a conference this year.<\/span><\/p>\n In an interview this week, Powell called for far stronger mosquito-control campaigns in the United States and other countries.<\/span><\/p>\n \u201cRather than treating each disease after there’s an outbreak, why not spend more money trying to control the mosquito?\u201d he said.<\/span><\/p>\n Aside from yellow fever, no vaccine exists for other aegypti-borne diseases such as dengue, chikungunya and Zika \u2014 although scientists have been racing to develop a Zika vaccine. Powell said scientists have linked the species to \u201chundreds\u201d of other viruses, mostly circulating among primates in Africa, that could one day cause the next global outbreak.<\/span><\/p>\n \u201cWe know they are there,\u201d he said. \u201cWe know it’s going to happen again.\u201d<\/span><\/p>\n Source:\u00a0https:\/\/www.washingtonpost.com\/news\/to-your-health\/wp\/2016\/11\/24\/as-the-aedes-aegypti-mosquito-spreads-globally-so-does-the-risk-of-epidemics\/<\/span><\/p>\n