Chikungunya is dengue like viral fever caused by an alphavirus, the chikungunya virus and transmitted by Aedes, Culex, and Mansonia mosquitoes. Chikungunya is also referred to as an arbovirus, owing to the manner in which it is transmitted: arboviruses are arthropod-borne viruses.
|Culex Mosquito Laying Eggs
The word chikungunya is derived from an African word which means `to bend or twist’, in reference to the stooped posture developed as a result of the arthritis associated with the disease. The name, chickungunya, comes from the Swahili for stooped walk, reflecting the physique of a person suffering from the disease.
The disease is manifested by high fever and severe articular pain in the limbs and spinal column.
Incubation Period: 4-7 days, following which the disease has a sudden onset
- fever, chills, cephalalgia, anorexia, lumbago conjunctivitis and adenopathy.
- 60 to 80 per cent patients have a morbilliform rash, occasionally with purpura on the trunk and limbs.
- The cutaneous eruptions may recur every 3 to 7 days. Other symptoms are coffee coloured vomiting, and petechiae.
- The arthropathy is manifested by pain, swelling and stiffness of the metacarpophalangeal, wrist, elbow, shoulder, knee, ankle and metatarsal joints. It appears between 3rd and 5th day after the onset of clinical symptoms and it can persist for many months and even years. Chikungunya fever is not lethal.
The disease occurs in rainy season when the vector population is at its peak.
Vector Control: The control of Aedes aegypti mosquito requires active community involvement to keep water storage containers free of mosquitoes and to eliminate the other breeding places of mosquitoes in and around houses and dwellings. The organophosphorus insecticide, Abate is increasingly used as a larvicide. It can prevent breeding for up to 3 months when applied on sand granules. It does not harm man and not affect the taste of water. Anti-larval measures can prevent an epidemic, but do not give immediate results when an epidemic has already broken. In such cases, anti-adult measures alone can bring about a rapid interruption of transmission. A new technique consisting of aerosol spray of ultra low volume (ULV) quantities of malathion or sumithion (250 ml/hectare) has been found to be effective in interrupting transmission and stopping epidemics of DHF. The tiny droplets kill the mosquitoes in the air as well as on water.