Reemergence of chikungunya virus

Abstract

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes acute fever and acute and chronic musculoskeletal pain in humans. Since 2004, CHIKV has caused millions of cases of disease in the Indian Ocean region and has emerged in new areas, including Europe, the Middle East, and the Pacific region. The mosquito vectors for this virus are globally distributed in tropical and temperate zones, providing the opportunity for CHIKV to continue to expand into new geographic regions. In October 2013, locally acquired cases of CHIKV infection were identified on the Caribbean island of Saint Martin, signaling the arrival of the virus in the Western Hemisphere. In just 9 months, CHIKV has spread to 22 countries in the Caribbean and Central and South America, resulting in hundreds of thousands of cases. CHIKV disease can be highly debilitating, and large epidemics have severe economic consequences. Thus, there is an urgent need for continued research into the epidemiology, pathogenesis, prevention, and treatment of these infections.

FIG 1

CHIKV in the Western Hemisphere. The World Health Organization (WHO) reported the first local transmission of CHIKV in the Western Hemisphere on the island of Saint Martin in December 2013. By 18 July 2014, the Pan American Health Organization (PAHO) reported more than 440,000 suspected and confirmed cases of chikungunya fever in more than 20 countries, with the majority of suspected and confirmed cases occurring in the Dominican Republic (251,951), Guadeloupe (64,328), Haiti (62,436), Martinique (50,455), Saint Martin (4,453), and Dominica (3,243). CHIKV has also spread to countries on mainland South America (French Guiana [881], Guyana [16], Suriname [17], Venezuela [2]), Central America (El Salvador [1,783], Costa Rica [1]), and the continental United States (Florida [2]). The number of cases in most of these countries continues to increase, and the virus continues to spread to new regions. The map (Maps for Design) shows the incidence rate of CHIKV infection in countries, territories, or states with autochthonous transmission as of 18 July 2014. (Case number and incidence rate data were obtained from PAHO, http://www.paho.org/hq/index.php?option=com_topics&view=article&id=343&Itemid=40931.)