Chikungunya fever

Chikungunya fever is an acute transmissible disease characterized by fever, intoxication and hemorrhagic syndrome.

Chikungunya fever was first described in Tanzania in 1952-1953. It was then registered in Zaire, Zambia, South Africa, Angola, Thailand, Burma, Singapore and India. The strains of the virus isolated in Asia differ little from the African isolates, but the diseases caused by the Asian variants are not accompanied by hemorrhagic manifestations.

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Epidemiology of Chikungunya fever

The reservoir and sources of infection are a sick person during the first 4-10 days of illness, virus-carrying monkeys and, possibly, bats, rodents and wild birds.

The mechanism of transmission of the pathogen is transmissible, the carriers of the virus in Africa are mosquitoes A. aegypti and A. africanus, in urban areas of India and Southeast Asia - A. aegypti. There is no data on direct transmission of infection from person to person.

Natural susceptibility of humans has not been established. The duration and intensity of post-infection immunity have not been studied.

Main epidemiological features. A clearly expressed natural focal disease is widespread in almost all of tropical Asia, a number of African countries (Zaire, Zambia, South Africa, Angola), and some Caribbean countries. The disease occurs exclusively among local residents and is extremely rare among visitors. Most cases of the disease are registered in young people and adolescents. Outbreaks usually occur during the rainy season in areas with a high breeding rate of A. aegypti mosquitoes. In addition to urban and suburban outbreaks, a number of countries also report a jungle type of disease associated with mosquitoes that feed on the blood of monkeys.

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Causes of Chikungunya Fever

Chikungunya fever is caused by an RNA genomic virus of the genus Alphavirus from the family Togaviridae, isolated from the blood of patients, from mosquitoes Aedes aegypti, A. africanus and Culex fatigans, bed bugs (living in the huts of patients) and bats. The virus is unstable in the external environment, is destroyed by ultraviolet rays, is heat-labile and sensitive to disinfectants.

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Pathogenesis of Chikungunya fever

The pathogenetic mechanisms of Chikungunya fever are similar to other hemorrhagic fevers.

Symptoms of Chikungunya Fever

Chikungunya fever resembles dengue fever, but the disease is much milder. The incubation period of Chikungunya fever is 3-12 days. The onset of the disease is accompanied by typical symptoms of Chikungunya fever - severe arthralgia and pain in the spine, immobilizing the patient. Bending positions in the joints somewhat relieve pain. Other symptoms include minor headache, anorexia, constipation. The fever is two-wave: waves of several days are separated by a period of apyrexia of 1-3 days. A maculopapular rash, accompanied by itching, appears on the trunk and extensor surfaces of the limbs. V.I. Pokrovsky emphasizes that there are no hemorrhagic manifestations in Chikungunya hemorrhagic fever, their presence excludes the possibility of Chikungunya hemorrhagic fever.

After 6-10 days, the patients' condition normalizes. No fatal outcomes have been registered.

Diagnosis of Chikungunya fever

With similar clinical signs to dengue hemorrhagic fever, the disease is distinguished by pain in the joints and spine, leading to immobility of the patient, and the absence of hemorrhagic manifestations.

Differential diagnosis of Chikungunya fever is carried out with other hemorrhagic fevers.

Laboratory diagnosis of Chikungunya fever is based on serological and virological studies.

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Treatment of Chikungunya fever

Treatment for Chikungunya fever is similar to that for dengue fever.

How is Chikungunya fever prevented?

Prevention of Chikungunya fever includes mosquito control and personal protective measures. Specific prevention measures have not been developed.