Chikungunya Outbreak in the Caribbean
February 1, 2014
Katherine E. Bliss,
Senior Associate, Global Health Policy Center
An outbreak of Chikungunya in the Caribbean raises concerns that virus could become endemic in the Americas and spread to United States. First-time local transmission of the vector-borne virus in the region has prompted health officials to boost surveillance for disease symptoms, including fatigue, joint pain, fever, headache, and rash, in areas where the mosquito that transmits the virus is prevalent.
Last December, 2013, the World Health Organization (WHO) reported two cases of local transmission of Chikungunya in the French territory of St. Martin. Since then nearly 300 cases in the Caribbean have been reported. “Local transmission” means that the mosquitoes that serve as vectors for the virus, primarily those from the Aedes genus, are spreading Chikungunya through bites from person to person.
It is the first time in the Americas that there has been local transmission of Chikungunya, which is found primarily in Asia and Africa. In recent years Chikungunya cases had been reported in the United States, Canada, Brazil, Guadaloupe, Martinique, and French Guiana, but these were classified as “imported” because they were observed in travelers arriving from regions where Chikunguyna is endemic and did not result in additional cases.
Chikungunya was first identified in Tanzania in the early 1950s, and the name, which means “that which bends” in the Makonde language, refers to the awkward posture of those experiencing painful virus-related symptoms. Anticipating that the virus might at some point secure a foothold in the Americas because of the prevalence of Aedes Aegypti and Aedes Albopictus mosquitoes in the region, in 2011 the Pan American Health Organization (PAHO), the regional arm of the World Health Organization, and the U.S. Centers for Disease Control and Prevention (CDC) released guidelines for regional health departments to follow in preparing for a Chikungunya outbreak. These include educating health care providers about Chikungunya symptoms and risk factors; bolstering surveillance for disease symptoms; implementing vector control measures; and raising community awareness about the importance of protecting against mosquito bites through the use of repellents or insecticide-treated bednets.
Chikungunya is rarely fatal, but, like the dengue virus, which is also transmitted by Aedes mosquitoes, can cause fever, pain, and fatigue. It can also lead to chronic joint pain lasting months or, in some cases, years. Less common effects include neurological symptoms and renal failure.
Sustained outbreaks in Asia and Africa in recent years also suggest the potential for considerable economic losses associated with Chikungunya. The Indian Ocean island of La Reunion reported a 60% decrease in tourism following an outbreak in 2005-2006. The fact that the current outbreak in the Caribbean is taking place during the prime winter tourism season creates two causes for concern: that tourists afraid of being infected with Chikungunya may cancel plans to travel to the region, dealing a blow to local economies, and that travelers infected with Chikungunya may take the virus home with them.
There is currently no vaccine for Chikungunya. Because the mosquitoes that transmit Chikungunya are often found in urban areas, the virus could spread quickly in the highly urbanized Americas if it extends beyond the Caribbean and preventive measures are not taken.
While there are no reports yet of local transmission of Chikungunya in the United States, the Aedes Aegypti mosquito’s range includes much of the U.S. southeast, with Aedes Albopictus found in the same area, plus the Great Lakes and mid-Atlantic regions, as well.