Mechanisms of Chikungunya Virus Disease Informed by Ross River Virus Research

Chikungunya virus (CHIKV) was first isolated in Tanzania in 1953. Since then, CHIKV outbreaks have occurred sporadically in Sub-Saharan Africa, southeast Asia and India. Most recently, in 2005/2006, a CHIKV outbreak was reported in a number of islands in the western Indian Ocean, which has since spread into India, giving rise to the largest CHIKV epidemic on record. Reports of CHIKV cases in Italy, a more temperate environment, have suggested the potential for this virus to spread worldwide. CHIKV, an Alphavirus belonging to the Togaviridae family, is maintained by transmission cycles between mosquito vectors and vertebrate hosts. Whilst CHIKV disease is generally not fatal, it can cause debilitating symptoms including fever, rash, headache, myalgia and arthralgia. Some more severe cases have been described, for example, in neonates where infection has been found to involve the CNS. As yet, there are no specific treatments available for CHIKV disease, although analgesics and nonsteroidal anti-inflammatory drugs can be given for symptomatic relief.