Chikungunya virus (CHIKV) is a mosquito-borne alphavirus and it can cause chikungunya fever, which is a viral infectious disease originated in Africa. Chikungunya virus is a member of the alphavirus genus, and Togaviridae family. The genus Alphavirus contains approximately 30 members, which probably diverged a few thousand years ago. Some alphaviruses are not pathogenic to humans, whereas others are highly infectious, with the associated clinical diseases ranging from mild to severe. Alphaviruses can be broadly divided into New world and Old world viruses. These two groups have evolved distinct ways of interacting with their respective hosts and differ in their pathogenicity, tissue and cellular tropism, cytotoxicity and interference with virus-induced immune responses. It should be noted that most alphaviral infections in humans and domesticated animals are considered a ‘dead end’ — that is, the virus cannot be transmitted to a new host, so the evolutionary pressures driving viral diversification may be linked to their true host species.
The most common symptoms of chikungunya virus infection are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash. Outbreaks have occurred in countries in Africa, Asia, Europe, and the Indian and Pacific Oceans. In late 2013, chikungunya virus was found for the first time in the Americas on islands in the Caribbean. There is a risk that the virus will be imported to new areas by infected travelers. There is no vaccine to prevent or medicine to treat chikungunya virus infection. Travelers can protect themselves by preventing mosquito bites. When traveling to countries with chikungunya virus, use insect repellent, wear long sleeves and pants, and stay in places with air conditioning or that use window and door screens. Figure 1 shows the schematic model of the chikungunya virus:
Fig. 1 The Schematic Model of the Chikungunya Virus
Several methods can be used for diagnosis of Chikungunya Virus. Serological tests, such as enzyme-linked immunosorbent assays (ELISA), may confirm the presence of IgM and IgG anti-chikungunya antibodies. IgM antibody levels are highest 3 to 5 weeks after the onset of illness and persist for about 2 months. Samples collected during the first week after the onset of symptoms should be tested by both serological and virological methods (RT-PCR).