Chikungunya is a viral disease can be transmitted to human by mosquitoes and causes significant symptoms, such as arthralgia and fever. It was first described in 1952 when an outbreak in southern Tanzania was observed.
Chikungunya is an RNA virus and a member of the alphavirus genus of the Togaviridae family. It has been identified in more than 60 countries worldwide in the continents of Asia, Africa, Europe and America.
The virus is passed on through bites of female mosquitoes that are infected. The mosquitoes may bite at any time but are most active outdoors during the early morning and late afternoon. The incubation period can range greatly from 2 to 12 days, but the initial symptoms typically present 4 to 8 days after the infected mosquito bite.
The initial signs of chikungunya include a sudden fever and joint pain. Symptoms may include:
- Arthralgia (joint pain)
- Myalgia (muscle pain)
These symptoms are usually short-lived and improve after a few days, but may extend over a period of a few weeks or longer. For this reason, the virus can be referred to as acute, sub-acute or chronic.
Most individuals that suffer from chikungunya make a full recovery, but some patients may notice permanent effects. Joint pain, in particular, is often reported to continue for several months or years after the initial infection.
Additionally, complications involving the eyes, heart and nervous system may also present. It is rare for complications to have a serious impact on overall health but the virus can contribute to the cause of death, usually in elderly people that have weaker immune defenses.
To diagnose chikungunya serological tests may be required. For example, enzyme-linked immunosorbent assays (ELISA) can identify the presence of antibodies against the virus. This is most effective several weeks after illness onset, but can help to identify the disease in this time period.
A virological test, such as reverse transcriptase-polymerase chain reaction (RT-PRC), may be more useful in the first week of symptoms to detect the presence of the virus before antibodies have developed.
As there is no antiviral drug currently available to treat chikungunya, the treatment is primarily driven towards symptomatic relief. It is important to maintain adequate fluid intake and encourage patients to rest while their body fights the viral infection.
For many patients, the joint pain is the most debilitating symptom and needs specific attention in the management of this condition. Often, analgesic medications are able to offer adequate relief. Non-steroidal anti-inflammatory drugs (NSAIDS) such as aspirin or ibuprofen are able to offer a significant improvement in pain, although other medications such as paracetamol are also effective.
Additionally, an antipyretic medication is usually preferable if there is fever present. Many drugs, such as paracetamol and aspirin, can offer pain relief and a reduction in fever simultaneously.
The most important factor for the risk of becoming infected with chikungunya virus is the proximity to mosquito vector breeding sites.
For this reason, prevention of the viral infection involves minimizing water-filled areas near residential areas that are ideal breeding grounds for the mosquitoes. Additionally, insecticides can be used to eliminate infected mosquitoes during an outbreak.
It is recommended that individuals wear full clothing to minimise skin exposure during the day when mosquitoes may bite. Insect repellants may also offer some protection, although physical coverage such as a mosquito net while sleeping is preferable.
It is wise for people travelling to areas known to have a higher risk of this viral infection to take appropriate precautions to avoid infection. There is no vaccine available, so appropriate clothing and insect repellent should be worn.