Chikungunya virus (CHIKV) is an arthropod-borne virus in the Togaviridae Family, genus Alphavirus. A number of these viruses cause arthralgia and arthritis in humans, including CHIKV, Ross River virus (RRV), Semliki Forest virus, Sindbis virus, o’nyong-nyong virus, and Mayaro virus. CHIKV was first isolated in 1952 in Tanzania [1]. CHIKV infections present with fever, rash and arthralgia leading to arthritis. Its name means “that which bends up”, referring to the stooped posture of patients. There have been numerous outbreaks of CHIKV disease in Asia and Africa: for example, the 2005-06 CHIKV outbreak in La Réunion resulted in approximately 260,000 cases, including 237 deaths [2], and the 2006-07 Indian outbreak had 1.5 million reported cases [3]. Mutations in CHIKV have led to an extension of its vector competence and an increase in its human disease potential. For example, a recentlyacquired single mutation in an envelope protein now allows Aedes albopictus mosquitoes to transmit CHIKV as well as Aedes aegypti [4]. Current treatment is symptomatic, and there are specific therapies available. The recent extensive CHIKV outbreaks have led to renewed interest in CHIKV antivirals, with a number of candidates currently under study. Chloroquine phosphate was reported to be beneficial in CHIKV arthritis [5]. However, this was not confirmed in a subsequent clinical trial [6], and in an animal model of alphavirus infection choloroquine was shown to promote virus replication and enhance disease. Treatment with ribavirin improved the resolution of joint swelling in CHIKV patients [7], and synergy between interferon-α and ribavirin for inhibition of CHIKV replication has been reported.