Chikungunya 

Chikungunya, pronounced chik-en-GUN-yah, is a viral disease transmitted through the bite of infected mosquitoes. Also known as chikungunya virus disease or chikungunya fever, it presents symptoms similar to dengue, including high fever, rash, and intense joint pain that can sometimes persist and resemble arthritis. While the illness can be debilitating, it is rarely fatal. Chikungunya is most commonly reported in Africa, India, and Southeast Asia, particularly in urban and peri-urban regions. Currently, there is no specific treatment for the disease, and care focuses on relieving symptoms.

1.0 Introduction

• Chikungunya, also referred to as chikungunya virus disease or chikungunya fever, is a viral infection transmitted by mosquito bites. 
• Although not life-threatening, it can be highly debilitating and shares symptoms similar to those of dengue fever.

2.0States Affected by Chikungunya

• The states affected by chikungunya are Andhra Pradesh, Karnataka, Maharashtra, Tamil Nadu, Madhya Pradesh, Gujarat, Kerala, A&N Island, GNCT of Delhi, Rajasthan, Pondicherry, Goa. 

3.0History of Chikungunya

• India experienced significant Chikungunya outbreaks in the last millennium, with major epidemics reported in 1963 (Kolkata), 1965 (Pondicherry and Chennai in Tamil Nadu; Rajahmundry, Visakhapatnam, and Kakinada in Andhra Pradesh; Sagar in Madhya Pradesh; and Nagpur in Maharashtra), and in 1973 (Barsi, Maharashtra). 
• Following these outbreaks, sporadic cases continued to appear, notably in Maharashtra during 1983 and 2000.

4.0Causes of Chikungunya

Chikungunya is caused by the chikungunya virus, which is classified in the family Togaviridae, genus Alphavirus.

5.0Mode of Transmission

• Chikungunya is transmitted through the bite of an Aedes mosquito, mainly Aedes aegypti. 
• Humans serve as the primary source, or reservoir, of the chikungunya virus for these mosquitoes. 
• The virus spreads when a mosquito bites an infected person and then goes on to bite someone else, passing the virus along. 
• Chikungunya is not a contagious disease—it cannot be spread directly from person to person. 
• The Aedes aegypti mosquito is most active and tends to bite during the daytime.

6.0Where is Chikungunya Found?

• Chikungunya is primarily found in Africa, India, and Southeast Asia. 
• The disease has also caused several outbreaks in the Philippines and on islands across the Indian Ocean. 
• These outbreaks are driven by a human-mosquito-human transmission cycle. 
• The Aedes mosquitoes responsible for spreading chikungunya commonly breed in various man-made containers that collect water—often found near human habitats. 
• These include discarded tires, flowerpots, old oil drums, animal troughs, water storage containers, and plastic food containers. 
• Poor public health infrastructure and environmental conditions that allow unchecked mosquito breeding significantly contribute to the risk of chikungunya and other mosquito-borne diseases.

7.0Symptoms of Chikungunya

• Chikungunya usually begins abruptly, presenting symptoms such as fever, chills, headache, nausea, vomiting, joint pain, and a skin rash. The name "chikungunya" is derived from a Swahili word meaning "that which bends up," referring to the characteristic bent posture often seen in patients due to severe joint pain, a hallmark symptom of the disease.
• In some cases, particularly in children, the infection may result in few or no symptoms. While most individuals recover fully, the recovery process can be slow, and joint pain may persist, sometimes requiring pain relief and long-term anti-inflammatory treatment. Infection generally provides lasting immunity.

8.0Diagnosis of Chikungunya

• Chikungunya is diagnosed through blood tests, specifically ELISA. Given the similarity in clinical symptoms between chikungunya and dengue, laboratory confirmation is crucial, particularly in regions where dengue is prevalent.

9.0Treatment for Chikungunya

• There is no specific cure for chikungunya. 
• Treatment focuses on relieving symptoms through supportive care, such as using non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation, along with plenty of rest. 
• To help prevent the spread of the virus, infected individuals should minimize their exposure to mosquitoes as much as possible, reducing the risk of further transmission to others.

10.0Prevention of Chikungunya

• Applying mosquito repellents to exposed skin and clothing
• Staying indoors in areas with proper screening or air-conditioning; if these are unavailable, using bed nets while sleeping
• Wearing long-sleeved shirts and long pants, particularly when working outdoors during the day
• Minimizing mosquito contact and eliminating standing water where mosquitoes breed, which can significantly lower the risk of chikungunya infection.

11.0Control of Aedes mosquito

Source Reduction

• Eliminating all potential mosquito breeding places in and around homes and nearby areas
• Avoiding water storage for more than a week by emptying and drying containers weekly
• Straining stored water with a clean cloth once a week to remove mosquito larvae; the cloth should be dried in sunlight to kill any larvae or pupae. The filtered water can be reused.

Use of Larvicides

When water cannot be discarded, especially for purposes like cattle use:

• Apply Temephos at a concentration of 1 ppm once a week to kill mosquito larvae
• Use Pyrethrum extract (0.1% ready-to-use emulsion) indoors to eliminate adult mosquitoes hiding inside rooms (not to be used outdoors)

Biological Control

Introduce natural predators like larvivorous fish such as Gambusia or Guppy in water tanks and other stagnant water sources to control mosquito larvae.