Chikungunya Epidemic Poses New Threat to Western Hemisphere and Possibly to the United States

July 16, 2014

Chikungunya, a mosquito-borne viral illness, could become firmly established in the Western Hemisphere posing a potential threat to the United States, according to a commentary in the New England Journal of Medicine by Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and David M. Morens, M.D., senior advisor at NIAID. Chikungunya was detected in the Caribbean in late 2013 and has now infected at least 355,000 people in more than 20 countries or jurisdictions in the Americas. So far in 2014, the U.S. Centers for Disease Control and Prevention has reported 232 cases among travelers visiting or returning to the continental U.S. from affected areas.

Chikungunya virus was not identified until the 1950s, but historians suspect the disease emerged in Africa and eventually arrived in Asia and the Americas two or more centuries ago, causing outbreaks before disappearing from the Americas. The strain now in the Caribbean appears to be transmitted by Aedes aegypti mosquitos, which also transmit dengue fever. The Caribbean chikungunya strain has not yet adapted to the more widespread Aedes albopictus mosquito, a vector that could potentially support transmission as well.

Although Chikungunya is rarely fatal, it can cause severe recurrent joint pain, and there are no approved vaccines or drug treatments. NIAID scientists are developing a vaccine that showed promise in a recent Phase I trial, and several other vaccine and treatment candidates are in early stages of testing at other institutions. In the meantime, the authors note the need for standard public health measures such as effective mosquito control and warn that clinicians should be alert to signs and symptoms so they can properly diagnose and report the disease. The authors say there is still hope that the epidemic will decline and depart from the Western Hemisphere.
DA Morens et al. Chikungunya at the Door-Déjà Vu All Over Again? New England Journal of Medicine DOI: 10.1056/NEJMp1408509.
NIAID Director Anthony S. Fauci, M.D., and David M. Morens, M.D., senior advisor at NIAID, are available for comment.
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Content last reviewed on July 16, 2014