Chikungunya fever is a viral disease and is caused by the Chikungunya virus, which belongs to the Togaviridae family. The virus is sensitive to heat (above 58 °C) and to dehydration, soap and disinfectants. A classification is made according to geographical localization into West African, East and South African, Central African, Asian and Indian Ocean virus.
The word Chikungunya comes from the language of the Makonde, an African people in southeastern Tanzania and northern Mozambique, and translates as "the one who walks bent", which is due to a characteristic symptomatology of the disease.
Chikungunya virus is widespread in numerous African countries (especially Gambia, Guinea, Senegal, Tanzania) and also circulates in many countries in southern and southeastern Asia (Indonesia, Cambodia, Malaysia, Maldives, Myanmar, Philippines, Sri Lanka, Thailand) as well as in the Near East and the Indian subcontinent. Since the end of 2013, more cases have also been observed on the Caribbean islands (Dominican Republic) and in the French overseas territories (St. Martin, Saint-Barthélemy, Martinique and Guadeloupe), in South and Central America (especially Brazil, Bolivia and Colombia) and in the United States of America. Isolated outbreaks have also occurred in southern Europe (Italy since 2007, France since 2015, Spain since 2017). The occurrence of chikungunya virus has been detected for more than 60 countries worldwide so far.
In the initial phase, there is usually a high fever that lasts for several days. In addition, there may be severe pain in the joints, limbs and muscles, so that it is often almost impossible to stand upright. These symptoms may persist for weeks to months after the fever. Maculo-papular rash (skin rash), swelling of the lymph nodes, headache, inflammation of the eyes and gastrointestinal complaints are other possible signs of the disease. The disease usually clears up on its own after one to two weeks and leaves a lifelong protection.
In up to 10% of cases, the joint complaints persist for months to years, in which case the infection is referred to as chronic. In rare cases, internal organs are involved, such as inflammation of the liver (hepatitis), inflammation of the heart (myocarditis, pericarditis) and meningitis. The treatment of Chikungunya fever consists of treating the signs of the disease; a therapy specifically directed against the virus does not yet exist.
In addition to clinical assessment, diagnosis is based on serological methods (enzyme immunoassay [EIA]) and molecular biological methods (reverse transcriptase polymerase chain reaction [RT-PCR]). In general, RT-PCR is recommended up to 5 days after symptom onset, and EIA after 5 days and beyond.