Number of people susceptible to painful mosquito-borne virus increasing, says leading researcher

In just two weeks, the number of Americans infected with the mosquito-borne virus chikungunya has almost doubled and the virus has now been found in mosquitoes in the United States, something that is very concerning to a Kansas State University professor who is a leading researcher of the virus.

At least 243 travel-related cases of chikungunya have been reported to the Centers for Disease Control and Prevention in 31 states, with the number expected to grow. The first case acquired in the United States was reported in Florida, seven months after the mosquito-borne virus was recognized in the Western Hemisphere.
Stephen Higgs, one of the world's leading researchers of the virus and director of Kansas State University's Biosecurity Research Institute, says many more people are now at risk of becoming infected.

Zika virus: New threat from tiger mosquito

In the group of viruses that includes dengue and chikungunya, a newcomer now has people talking about it. Also originating in Africa, zika was isolated in humans in the 1970s. Several years earlier, only a few human cases had been reported. It took until 2007 for the virus to show its epidemic capacity, with 5,000 cases in Micronesia in the Pacific, and then especially, at the end of 2013 in Polynesia, where 55,000 people were affected. In light of these recent events, researchers from IRD and the CIRMF in Gabon restarted work on the concomitant dengue and chikungunya epidemic that occurred in 2007 in the capital, Libreville, and which affected 20,000 people. Showing almost the same symptoms as its two dreaded cousins, did zika pass unnoticed by the researchers?

Climate, genetics can affect how long virus-carrying mosquitoes live

It's just math: The longer a mosquito lives, the better its odds of transmitting disease to humans or animals.

But as it turns out, factors such as the mosquito's own genetics and the climate it lives in have a big -- albeit complicated and not wholly understood -- role to play in its lifespan.
University of Florida researchers, hoping to better understand how West Nile virus affects mosquitoes, set up an experiment they outline in the Journal of Vector Ecology's current issue.
Mosquitoes can transmit any number of pathogens to humans, including protozoan malaria, West Nile, dengue and chikungunya viruses. Malaria cases range between 350 million and 500 million each year, with 1 million to 3 million deaths every year.
In the experiment, UF researchers examined survival rates for mosquitoes from two laboratory-reared colonies, one from Gainesville and one from Vero Beach.
Half of each of the mosquito colonies was fed West Nile virus-infected blood, the other half kept as a control population, and fed blood without the virus.
They divided the groups once more, this time keeping the mosquitoes at two temperatures, one group at 80.6 degrees, the other at 87.8 degrees Fahrenheit -- a rather large difference in temperature for cold-blooded insects.
Their findings were both unexpected and illuminating, said Barry Alto, a UF assistant professor of arbovirology based at the Florida Medical Entomology Laboratory in Vero Beach.