Relapsing fever - an acute infectious disease. Pathogens
relapsing fever are lice (epidemic relapsing fever) or mites (endemic relapsing fever). The illness with alternating bouts of fever and periods of remission.
Relapsing fever can be sick in all regions except for Australia. The highest probability to be ill with typhus, and in the most severe forms - in Africa. For example, in Sudan, after the First World War for ten years from the disease have died around 100 thousand people.
Distributed relapsing fever in India, in Russia and in the Balkans. In Iran, India, Southeast Asia, more common epidemic relapsing fever, caused by overcrowding of people in unsanitary conditions. In Europe, Asia, Africa, South America, relapsing fever are a carrier of lice genus Pediculus, parasitic on humans.
In Europe, Asia, Africa, North and Central America tick-borne relapsing fever occurs. Carrier of relapsing fever ticks are kind Ornithodorus.
What factors provoke relapsing fever?
To the agents of relapsing fever spirochetes are kind of Borrelia. Tick-borne relapsing fever is a zoonotic vector-borne disease caused by Borrelia are various kinds: B. saucasica V. latyschewii, V. hispanica, V. persica, V. duttonii.
According to its biological, morphological characteristics similar to those Borrelia agents of epidemic typhus.
Carriers relapsing fever
Carriers of tick-borne relapsing fever ticks are family Argas persicus, Argasidae, which are reservoir hosts of spirochetes. Moreover, the reservoir may be different Borrelia species of rodents. Mites are contagious during the whole period of life (about 10 years). Usually, human infection is due to a tick bite. Most often it occurs in warm seasons during the activation of vital activity of ticks.
Transmit epidemic relapsing fever are lice P. humanus humanus (Hanging), Pediculus humanus capitis (head) and Phtirius pubis (pubic). Epidemic relapsing fever may be the only people hurt.
The pathogenesis of relapsing fever
Borrelia when ingested human lymphoid cells are introduced macrophage system, which begin to multiply and in much larger quantities enter the blood. Under the influence of the bactericidal properties of the blood they begin to break down in part to the release of endotoxin, which affects the central nervous and circulatory systems. Defeat systems associated with fever, and liver and spleen foci of necrosis appear. Borrelia, lingering in the capillaries of the internal organs, disrupt local blood supply, thereby developing a hemorrhagic infarction.
The first period of the disease is accompanied by fever, it completes the body's production of antibodies to Borrelia first generation. As a result, most of the killed Borrelia that are clinically expressed in the offensive period of remission. However, part of Borrelia changing its antigenic properties and is resistant to antibodies. They
begin to multiply again, and if it enters the blood causes a new bout of fever. Antibodies generated against the second generation of Borrelia also destroyed most of them, but not all. This again triggers a relapse. Full recovery occurs only when there is a full range of blood antibodies that destroy all mutations barrel. At the same time after recovering immune to the disease does not occur, because antibodies persist in the body for a short time.
The symptoms of relapsing fever
The first attack of relapsing fever begins suddenly. The patient feels short-term fever, which is replaced by an increase in temperature. A headache, pain in muscles and joints, nausea, vomiting. The temperature rises rapidly, the skin becomes dry, the pulse quickens, there is delirium. Peak attack is accompanied by a rash on the skin, the development of jaundice and enlargement of the liver and spleen. While fever may develop pneumonia or bronchitis, is showing signs of heart disease. The first attack lasts for 2-6 days. Then comes the period of remission, the patient feels better. But after a few days of developing a second attack of the disease, which has similar symptoms.
For epidemic relapsing fever characterized by a number of similar attacks, which usually ends in complete recovery and the onset of the temporary immunity to the disease. For tick-borne relapsing fever is characterized by four or even more such attacks, which, however, have a more mild symptoms and continue lower. But it happens that a second attack occurs much more difficult than the first.
Relapsing fever is fraught with the development of complications: uveitis, meningitis, synovitis, ruptured spleen, iridocyclitis, iritis.
Diagnosis of relapsing fever
Diagnosis of the disease is based on epidemiological data and clinical manifestations. Important in the diagnosis of relapsing fever plays study peripheral blood. During the attack in a patient's blood is fairly easy to detect the pathogen.
Treatment of relapsing fever
Treatment of epidemic relapsing fever is the use of antibiotics (chloramphenicol, penicillin, chlortetracycline) and preparations of arsenic (novarsenol).
For the treatment of endemic relapsing fever using tetracyclines, ampicillin, chloramphenicol.
Prevention of relapsing fever
Prevention of the disease is reduced to the fight against pathogens. Avoid contact with sick pediculosis. Currently, in our country and in other countries the epidemic fever is a rare disease.
Endemic relapsing fever prevention is to protect persons from contact with pincers and in the destruction of rodents and other vectors in natural outbreaks.