Kansas State University

MANHATTAN — Cases of chikungunya continue to rise, with more than 100 people from the United States infected with the mosquito-borne virus that they contracted while out of the country, according to the Centers for Disease Control and Prevention.

Kansas State University's Stephen Higgs, one of the world's leading researchers of the virus and director of the university's Biosecurity Research Institute, says precautions should be taken to avoid a chikungunya outbreak in the U.S.

Higgs has been studying chikungunya for almost 10 years, and he and his collaborators have published 30 works on the virus. They also produced an infectious clone of the disease that is widely used by other researchers, and they are assisting with efforts to develop a vaccine for chikungunya.

"The concern is that the two types of mosquito that transmit chikungunya virus, Aedes aegypti and Aedes albopictus, are widely distributed in the United States," Higgs said. "There is potential that somebody could come from overseas not knowing they are infected with the virus, because it takes a few days between getting infected and getting sick. If they unknowingly bring the disease to the United States, our mosquitoes could feed on these people when they have the virus in their blood and pick up the virus. Then we would have transmission in the United States."

Chikungunya is an African Makonde word that means "to bend up." It describes a crippling arthritis that can be so intense that it actually causes the person to bend up in pain, Higgs said. No vaccine or treatment for the virus is available and it can take days, weeks or sometimes longer to go away.

"Most of the people who get infected do get sick, unfortunately," Higgs said. "The fatality rate is relatively low, but has seemingly increased over the last few years for reasons we don't know."

The infectious potential of the virus also has increased, according to Higgs' research.

"One of the really strange things that happened with this virus when it got into the Indian Ocean is that it started being transmitted by the Asian tiger mosquito," Higgs said. "It was known that this mosquito could transmit the virus. What my group of researchers proved was that a single-point mutation occurred in the virus genome that altered the surface of the virus, making it 100 times more infectious for that particular mosquito."

The chikungunya virus was first discovered in the 1950s in Tanzania. Since then, there have been outbreaks in India, Asia, the French islands and most recently in the Caribbean.

According to the CDC, the best way to prevent getting the virus is to not get bitten by mosquitoes. That means to avoid going outside at dusk and at dawn, when mosquito activity is high; use repellant when you do go outside; and get rid of standing water around your house, such as in potted plants, because this is a breeding ground for mosquitoes. Also check the CDC website for information before traveling to infected areas. If you think you may have been infected, contact your doctor.