The Chikungunya virus (CHIKV) was first isolated from a patient in Africa in the early 1950s.
Chikungunya means “bent up” in the Bantu language, referring to the posture CHIKV causes from a severe viral arthritis. In its chronic stage, the virus can mimic rheumatoid arthritis (RA). 1
CHIKV is known to cause large outbreaks with high attack rates. The virus received global attention in 2005 when outbreaks in the Indian Ocean islands affected more than 250,000 people. On some islands, infection rates ranged from 34 to 75%.1 In 2013, the disease spread out of the Eastern Hemisphere into the Caribbean. 2
“Chikungunya is now spreading through the Caribbean and Central America like a wildfire,” said Davidson Hamer, MD, professor of global health and medicine at the Boston University School of Public Health and School of Medicine. “With the number of Americans who vacation in the Caribbean, it was only a matter of time before cases showed up in the United States.”
Incidence and Etiology
Since CHIKV became a notifiable condition in 2015, the Centers for Disease Control and Prevention (CDC) has reported 78 locally transmitted cases in Puerto Rico and the Virgin Islands. As of the end of May, a total of 146 cases have been reported in the United States, but all were in travelers returning from affected areas. 3
“Chikungunya is still exceedingly rare in the United States, but it is not hard to imagine that there are or will be some locally transmitted cases. If a person returns from traveling [carrying] the virus, a mosquito may bite that person, become infected, and bite another person,” said Jennifer Layden, MD, PhD, assistant professor in public health and infectious disease at Loyola University Medical System in Maywood, Illinois.
CHIKV is spread by the Aedes aegypti and Aedes albopictus mosquitoes, which are common in areas of the tropics and subtropics. Both types aggressively bite in the daytime instead of being active mostly at dawn and dusk like typical mosquitoes[JR1] . 1,2 “These are the same mosquitoes that transmit dengue fever. It is possible that chikungunya has been around a lot longer than we think but was diagnosed as dengue,” said. Hamer.