Chikungunya

Chikungunya (CHIKV), an emergent alphavirus, is responsible for several infectious outbreaks around the world. It is one of 29 distinct species belonging to the Togaviridae family, genus Alphavirirus. This virus was first described during an outbreak in southern Tanzania in 1952, and its name is derived from the Makonde language, meaning “to become contorted” or “that which bends up.” These descriptors refer to the hallmark of this disease in adults—namely, severe incapacitating arthralgia, leading to an inability to stand or walk. The virus is transmitted to humans by the bite of the Aedes mosquito.

Infection may have different clinical presentations in children and adults. Rates of asymptomatic infection have been variable among children (range 35–40%) in different outbreak scenarios.

Myalgia (60-93%), arthralgia and arthritis (87-99%) are often present in adults with Chikungunya, but these are typically less common in children (30% - 50%). In adult patients, chronic inflammatory polyarthritis has been reported following CHIKV infection, with involvement of the large and small joints of the hands and feet. Persistent or recurrent arthralgia lasting up to a year occurs in as many as 57% of adults, while arthralgia/arthritis may persistent for 3–5 years in almost 12%. Permanent destruction of the affected joints has been reported in some cases.

In children, arthralgia/arthritis persisting for up to two years occurs in around 5–11%. CHIKV should be suspected when a child presents with acute onset high-grade fever, rash and/or arthralgia and/or joint oedema and other infectious are excluded. The diagnosis of CHIKV becomes more likely if a child has visited or lives in an endemic/epidemic area.  The diagnosis is confirmed with CHIKV serology.