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. Then it was registered in Zaire, Zambia, South Africa, Angola, Thailand, Burma, Singapore and India. The strains of the virus isolated in Asia differ little from African isolates, but diseases caused by 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 for 4-10 first days of illness, monkeys-virus carriers and, possibly, bats, rodents and wild birds.

The mechanism of transmission of the pathogen is vector-borne, the carriers of the virus in Africa are mosquitoes A. Aegypti and A. Africanus, in urban areas of India and Southeast Asia - A. Aegypti. Data on direct transmission of infection from person to person are absent.

The natural susceptibility of people is not established. The duration and intensity of post-infection immunity has not been studied.

The main epidemiological signs. A clear natural focal disease is spread almost throughout the whole of tropical Asia, several countries in Africa (Zaire, Zambia, South Africa, Angola), in some countries of the Caribbean. The disease occurs exclusively among local residents and is extremely rare among visitors. Most cases of the disease are recorded in young people and adolescents. Flares, as a rule, occur during the rainy season in areas with high anemia of A. Aegypti mosquitoes . In addition to urban and suburban outbreaks, a number of countries also note the jungle type of diseases associated with mosquitoes feeding on the blood of monkeys.

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Causes of Chikungunya fever

Chikungunya fever is caused by the RNA genomic virus of the genus Alphavirus from the Togaviridae family , isolated from the blood of patients, from mosquitoes Aedes aegypti, A. Africanus and Culex fatigans, bed bugs (inhabiting sick huts) and bats. The virus is unstable in the external environment, is destroyed under the influence of ultraviolet rays, is thermolabile and sensitive to disinfectants.

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Pathogenesis of Chikungunya fever

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 easier. The incubation period of Chikungunya fever is 3-12 days. The onset of the disease is accompanied by typical symptoms of Chikungunya fever-strong arthralgias and pains in the spine that immobilize the patient. Bent positions in the joints somewhat ease the pain. Among other symptoms, there is a slight headache, anorexia, constipation. Fever is a two-wave: the waves are separated for several days by a period of apyrexia in 1-3 days. On the trunk and extensor surface of the limbs there is a maculopapular rash, accompanied by itching. IN AND. Pokrovsky emphasizes that there are no hemorrhagic manifestations with Chikungunya's hemorrhagic fever, their presence excludes the possibility of Chikungunya's hemorrhagic fever.

After 6-10 days, the condition of patients is normalized. Lethal outcomes are not registered.

Diagnosis of Chikungunya fever

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

Differential diagnosis of Chikungunya fever is conducted 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 of Chikungunya fever is similar to that of dengue fever.

How is Chikungunya fever prevented?

Prevention of Chikungunya fever includes fighting mosquitoes and measures of individual protection against them. The means of specific prevention are not developed.