Chikungunye fever ‒ the acute viral infectious disease with an inoculable way of transfer caused by the arbovirus of the same name. Specific display of fever is the inflammation of joints ‒ polyarthritises. High fever, intoxication symptoms (weakness, fatigue, decrease in working capacity, a moderate headache) and rashes are also characteristic of clinic of a disease. Diagnosis of fever is based on detection of the activator (a chikungunye virus) and antibodies to it in blood of the person. Treatment is symptomatic: the febrifugal and anesthetizing medicines, antihistamines, vazoprotektor.
Chikungunye fever – the viral infection which is transmitted at a sting of the mosquitoes belonging to a kusaka sort. It was for the first time described in 1952 after flash in Tanzania, then also the causative agent of fever was open. Means "Chikungunye" on one of the African dialects "to be bent": because of strong artralgiya the patient seeks to reduce pains decrease in any movements – sometimes by dying down in the most fancy poses. This infection is urgent for the countries of Africa and Asia, islands of the Indian Ocean. The number of new cases usually increases during a rainy season, especially among residents of agricultural areas, lethal outcomes are registered at senior citizens more often. On the European continent, in North and South America fever meets mainly in the form of brought in cases. In the Russian Federation an environment is considered adverse for a vyplod of mosquitoes-kusak therefore single episodes of fever are registered, is more often at the patients who came back from trips to endemic areas.
Chikungunye fever reasons
The causative agent of an infection – the RNA-containing chikungunye virus classified as (transferred at a sting of arthropods), the representative of family of Togavirusa, a sort Alfavirus. Sources and tanks of an infection are sick people, primacies and some rodents, carriers – females of mosquitoes of the sort Aedes. Depending on a look these mosquitoes can live and attack both outside (in the morning), and indoors (most often mosquitoes live in vases, pallets for flowers and plants, in bowls for feeding of pets). The sick person does not constitute danger to people around, but can be a source of infection of mosquitoes, and those are other people.
Primary way of infection – inoculable (at a sting of a blood-sicking insect). There are assumptions that transfer of the activator is possible at contact of blood of the sick person with blood healthy (for example, at joint intravenous administration of drugs one syringe, blood transfusion, use of unsterile tools in medical institution), but authentically cases of similar infection with fever of a chikungunye are not registered. The activator is unstable in the environment, perishes at action of high temperatures, ultraviolet and usual doses of disinfectants.
The pathogenesis of a disease is studied insufficiently. It is considered that at a sting a female of a mosquito together with saliva the virus of a chikungunye gets to blood of the person. The activator strikes endoteliya of vessels in which cages actively breeds and collects, getting then into a blood-groove. The virus of a chikungunye shows a tropnost to articulate fabric, however, there are data on involvement in pathological process of a cardiac muscle, a digestive tract, eyes and a brain. Defeat of a vascular wall increases its permeability that leads to an exit of plasma and uniform elements (generally erythrocytes) in fabric and is clinically shown by a hemorrhagic syndrome. Existence and tension of immunity after an infection are investigated now.
Chikungunye fever symptoms
The incubatory period makes 4-8 days, in certain cases can be shortened up to 2 days or be extended up to 12 days. The onset of the illness is always sharp, sudden against the background of satisfactory health. Sharp temperature increase of a body, quite often to high figures is characteristic at once (390C and above). Fever is followed by oznoba, sharp weakness, loss of appetite and muscular pains.
Patognomonichny is developing of the most severe articulate pains affecting small joints: wrists, foot, ankles, brushes. Joints considerably increase in sizes, becoming almost motionless, and in attempt of the movement there is sharp pain which is a little decreasing at rest. To the touch joints hot, swelled up a little, with reddish skin over them. The so-called migrating polyarthritis ‒ is characteristic of fever articulate changes pass from one extremity to another, and the previous defeat disappears independently.
Patients often show complaints to belly-aches, failures of a chair, nausea and is rare – vomiting. On skin of the top half of a trunk, the top and lower extremities the papular (bugorkovy) rash with the expressed itch passing then with a small peeling is found in patients. As the chikungunye virus pathologically changes a wall of vessels, developing of petekhialny (dot) rashes, desnevy and nasal bleedings is frequent.
In hard cases emergence of bleedings from digestive tract, urinogenital ways, hemorrhages to a retina of an eye and a brain is possible. After recovery can it is long to remain rigidity of joints. Accession of a secondary bacterial infection in connection with invasive methods of diagnostics and treatment is not excluded (blood sampling, artificial ventilation of lungs, injections, installation of intravenous and uric catheters), stagnant pneumonia quite often develops. Deaths of fever are most often caused by the late request for medical care and development of a syndrome of disseminirovanny intra vascular fibrillation (DVS-syndrome).
At suspicion of fever of a chikungunye consultation of the infectiologist, dermatovenerologist and therapist is obligatory, at emergence of symptoms of damage of eyes and a brain – the ophthalmologist and the neurologist. Basic diagnosis of infectious pathology includes laboratory and tool methods:
- Definition of infectious markers. From the first days of a disease it is possible to allocate the activator from the patient's blood by means of PTsR. By IFA method blood test on existence of antibodies to a virus of a chikungunye is conducted in dynamics – at the address of the patient and in 14 days. Double growth of a caption of antibodies is necessary for confirmation of the diagnosis a minimum.
- Kliniko-biokhimichesky blood tests. In the general blood test at infection with a virus of a chikungunye the leykopeniye and thrombocytopenia, acceleration of SOE are observed. Biochemical indicators reflect increase in the SRB level, activity (ALT, nuclear heating plant), is more rare – increase in content of bilirubin.
- Beam research of joints. Ultrasonography of joints allows to reveal existence of inflammatory changes, including an articulate exudate. Radiological damage of joints at fever of a chikungunye has no the expressed morphological features therefore the artrografiya is applied, mainly, for the purpose of an exception of other artropatiya.
Differential diagnostics is carried out with other hemorrhagic fevers (tenge, valleys Rift, Crimean hemorrhagic, Lassa, Marburg and Ebola) and infections (flu, leptospirosis, malaria, hepatitis B, typhus and paratyphus). It is also necessary to exclude autoimmune vaskulita, oncological diseases, pneumonia, a diabetes decompensation, pyelonephritis, an urolithic disease, sepsis, syphilis and rheumatoid arthritis.
Treatment of fever of a chikungunye
Therapy is carried out in an infectious hospital. The bed rest up to 2-3 days of steady decrease in body temperature, application of anti-mosquito grids over a bed, plentiful drink and frequent fractional food with an exception of greasy, fried food, alcohol and seasonings is recommended. At this stage of development of medicine specific antiviral treatment of fever of a chikungunye is not developed; therapy of a disease symptomatic (febrifugal, soothing, the antihistamines, medicines strengthening a vascular wall). Use of aspirin and its analogs at this infectious pathology is forbidden because of possible strengthening of a hemorrhagic syndrome.
Forecast and prevention
The forecast at in due time revealed infection favorable, various complications and deaths meet at the weakened, elderly faces and children more often. In population where there is no immunity to a disease and there are conditions for a mass vyplod and existence of mosquitoes carriers of a virus of a chikungunye, fever is capable to be transmitted in high gear and to strike a large number of healthy faces (that is especially noticeable at annual flashes in the African countries). At an uncomplicated current the disease lasts about two weeks, at the same time articulate pains independently pass in 80% of cases. At a part of patients of an artralgiya can remain more than half a year after the postponed infection.
It is reported about creation of a vaccine against chikungunye fever, however today medicine still passes registration stages. Further the vaccine can be used for immunization living in areas with high incidence, and also for the persons wishing to visit them with the tourist or labor purposes. Nonspecific prevention means fight against mosquitoes, timely identification and isolation of patients. The persons which are in habitats of disease carriers should use clothes of the closed type, protective grids and repellents.