The Pan-American Health Organization reports 155 reported deaths as of December 12, almost all in the Caribbean island nations of Guadeloupe and Martinique. There have been 1,900 cases reported in travelers returning to the United States.
Chikungunya is marked by severe joint pain, inflammation, headaches, rashes and fever. If the infection is severe enough, it can lead to death. Symptoms can persist for months in those who survive, causing debilitating arthritis.
The virus, which has symptoms similar to dengue fever, has long been a scourge in Asia and Africa. In fact the name, Chikungunya, comes from the African Makonde dialect, meaning "bending over in pain."
There is currently no vaccine or treatment for the disease.
Chikungunya is carried by two mosquito species -- Aedes aegypti and Aedes albopictus -- that also transmit the dengue virus. Chikungunya, which is carried in the blood, is picked up by mosquitoes after they bite an infected person and spread when the insects then bite uninfected individuals.
Public health officials worry that the virus could persist in the Americas for months, as climate conditions in the tropical countries are ripe for the insect carriers to flourish.
They warn that Chikungunya cases could escalate in a number of South American countries, including Brazil, Peru and Paraguay, with the approach of the summer months.