A mosquito-borne disease has reared its head in Karachi, affecting thousands of people in Malir, Saudabad and Shah Faisal neighbourhoods of the city. World Health Organisation (WHO) says it is Chikungunya virus that can become epidemic in the country.
Chikungunya is a viral disease transmitted to humans by infected mosquitoes. It causes fever and severe joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash.
Joint pain is often debilitating and can vary in duration.
The disease shares some clinical signs with dengue, and can be misdiagnosed in areas where dengue is common.
There is no cure for the disease. Treatment is focused on relieving the symptoms.
The proximity of mosquito breeding sites to human habitation is a significant risk factor for chikungunya.
The disease occurs in Africa, Asia and the Indian subcontinent. In recent decades mosquito vectors of chikungunya have spread to Europe and the Americas. In 2007, disease transmission was reported for the first time in a localised outbreak in north-eastern Italy. Outbreaks have since been recorded in France and Croatia.
Chikungunya is a mosquito-borne viral disease first described during an outbreak in southern Tanzania in 1952. It is an RNA virus that belongs to the alphavirus genus of the family Togaviridae. The name "chikungunya" derives from a word in the Kimakonde language, meaning "to become contorted", and describes the stooped appearance of sufferers with joint pain (arthralgia).