Chikungunya is an infectious disease caused by a virus that is transmitted by the Aedes mosquito, which is also the responsible vector for transmission of dengue and yellow fever. This disease occurs episodically every few years in various parts of Africa, Asia and the Indian Subcontinent. The major clinical feature is severe joint pains which can often last from 6 to 12 months or even longer.
The virus is taken up by the Aedes mosquito during a blood meal from an infected human and transmits it to another human through a bite. The virus multiplies in the skin before spreading through the body to affect to the joints.
There are three clinical phases of the disease depending on the duration of symptoms experienced, these are:
- Acute disease: This lasts less than 3 weeks marked with fever and joint pain and swelling, with associated headaches, muscle aches and skin rash.
- Post-acute phase: This lasts from 3 weeks to 3 months after the acute stage which is characterized by continued joint pain. About 50 % on patients experience this stage.
- Chronic phase: This phase is experienced by 5% of patients with persistent joint paint lasting over 3 months from initial disease and may continue for many years. A small number may develop chronic rheumatic arthritis as well.
Symptoms of Chikungunya
- High grade fever
- Joint pains involving multiple joints including the wrist, ankles, fingers, elbows, toes and knees
- Joint swelling and redness may be present
- Muscle pains and tenderness
- Skin rash which is usually a red pin point size rash present all over the body
- Bleeding from nose and gums
Diagnosis of Chikungunya
The diagnosis suspected clinically based on the nature of symptoms in the background of residence or travel to an area experiencing an outbreak. The disease is confirmed using the following blood tests
- Complete blood test: There may be a fall in the platelet level and white blood cell count in the body.
- Viral Nucleic Acid Detection: This detects viral genetic material using polymerase chain reaction (PCR).
- Viral antibody testing: The IgM and IgG antibodies produced by the immune system are tested. IgG is produced after the initial stage and is useful for diagnosis in the post acute and chronic phase.
Treatment of Chikungunya
There is no definitive treatment for Chikungunya. Management is targeted at controlling symptoms of the illness. The acute phase does have a risk for development of shock in severe cases and may require hospital admission with fluid hydration therapy.
- Acute Phase: Pain control is provided using paracetamol or acetaminophen. Tramadol may be used in severe cases. Non steroidal anti-inflammatory drugs are avoided as there is a risk of bleeding from suppressed platelet activity.
- Post-acute phase: NSAIDS like ibuprofen may be helpful. Steroids have been found to offer some benefit
- Chronic phase: this phase is treated similar to rheumatoid arthritis with a combination of immunosuppressants like methotrexate and Sulfasalazine along with physiotherapy and exercise.
Prevention of Chikungunya
The disease can be prevented by controlling outbreaks effectively and protecting against mosquito bites.
- Infected individuals must sleep under bed nets
- Personal protection from mosquitoes including
- Avoiding infested areas
- Wearing protective clothing
- Regular indoor spraying using DEET or icardin
- Using mosquito repellent creams, bed nets and mosquito coils during sleep
There is currently no available vaccine to protect against Chikungunya.