How many times are ill with scarlet fever? Treatment, prevention and etiology
Content
Scarlet fever – antropologia infection with airborne transmission mechanism, manifested by sore throat, rashes and intoxication, they suffer usually children.
Streptococci were first isolated by T. Billroth in 1874.
Scarlet fever existed at all times, description of similar symptoms can be found in the writings of Hippocrates, and Avicenna, but to the XVI century, it is not separated from other diseases accompanied by a rash. For the first time a separate disease described in 1564 by the Italian physician doctor of Ingrassia. Repeatedly and independently from the first researcher described her German I. Weir in 1565.
In 1905, G. N. Gabrichevsky and Savchenko, I. G. suggested that the cause of the disease is Streptococcus. Subsequently, this hypothesis was proved by I. V. Ioffe, F. Griffth, R. Lancefield.
Etiological (designed to cause) the treatment of scarlet fever began simultaneously with the advent of antibiotics. In 1906, Alexander Fleming discovered penicillin, which is still effective against streptococci.
Etiology
The cause of the disease – beta-hemolytic Streptococcus group A. Looks like a round immobile bacterium, capable of forming chains. No flagella, in adverse conditions, form a capsule, and not dispute.
All streptococci by the ability to lyse the red blood cells can be divided into three groups:
- alpha partially destroys red blood cells, forming around the colony greenish halo,
- beta completely destroy them, around the colonies formed a bright circle without blood cells,
- gamma does not interact with erythrocytes.
On the surface of bacteria is a large variety of antigens. In their combinations they can be divided into groups, denoted by the Latin letter. At the moment there are twenty serovars, i.e., A through V. Pathogenic human A-G. grow best at a temperature of 370 oC and neutral pH. A colony on solid medium looks like a rough rough circle. Stable in the environment, in biological material can be preserved for up to a month, well during drying. Easily destroyed with disinfectant substances.
Epidemiology
The source of infection – people who suffer any streptococcal disease (scarlet fever, erysipelas, angina) and asymptomatic carrier of a microorganism. There is evidence that carriers of bacteria is 20% of healthy people. Their detection and treatment reduces the epidemiological tensions.
The mechanism of transmission – aerosol. Way – airborne and air-dust. The bacterium is common in all latitudes of the globe, but often affects children living in temperate and cold climates. The peak incidence falls in the summer, in the rest of the year, while maintaining roughly the same value.
Approximately every 40-50 years is recorded epidemic rise in the incidence, which increases the number of infected increases, the percentage of severe forms.
Newborns often protected from infection by maternal antibodies that gets the milk. In children aged two years increases the risk of Contracting scarlet fever. Difference in incidence by gender is not revealed, the boys found with the same frequency as that of the girls.
Features of formation of immunity
After the transfer of disease resistant is formed antitoxic and antimicrobial immunity.
Secreted toxin is similar for all variants of bacteria, so the immune system protects children from getting sick again. Treatment with antibiotics given in the first two days of the onset of the disease, reduces the immunity and increases the risk of repeated infection by 3-5%.
Antimicrobial immunity is based on the production of antibodies to a streptococcal protein-M. After the transfer of the infection, the antibodies circulate in the blood for life. This means that the microorganism with a specific type of protein-more is not terrible, disease scarlet fever he will not. There is 110 variations of this protein during infection other serological variants of the pathogen will develop other streptococcal disease: sore throat, sinusitis, otitis, erysipelas, and others.
So, how many times are ill with scarlet fever? Often one, the chance of catching it again is 3-5%.
Pathogenesis
The causative agent is introduced into the body through the mucous membranes of the mouth, nose, or throat. Implementation using other gates: the wound surface, mucous membrane of the uterus is rare and causes atypical forms.
Exert their effects due to the presence of virulence factors:
- Erythrogenic exotoxin (a toxin dick) has the ability to increase the temperature, to extend the small vessels, including in the skin, increase the permeability of cell membranes. Under its action the epidermis swells, soaked with exudate. This leads to keratinization and subsequent peeling of its layers.
- Endotoxin causes septic complications in places of distribution of Streptococcus.
- Protease, hyaluronidase and other enzymes that destroy the surrounding tissue, creating a platform for the bacteria and also protects against uptake by phagocytes.
Clinic
The incubation period lasts up to a week. Start of acute, febrile fever (380-400C) with headache, chills, nausea. In children having complaints of pain in the throat when swallowing. The tonsils and soft palate bright red, "burning". They can distinguish between necrotic white tube like angina. Sometimes on the soft palate too rash.
Lymph nodes near the gates of implementation increase in size, become painful when pressed.
This disease typically looks language: in the beginning covered with a thick bloom, which gradually cleared, leaving a bright red surface, with enlarged papillae ("raspberry tongue"). Salivation is reduced, therefore, the oral mucosa dry.
The second joins petechial rash is pink in color, it occurs on the background of reddened skin in children is especially pronounced in the folds and creases. It is hemorrhagic in nature, that is disappears after pressing. Sometimes the lesions are so close to each other that the impression of the drain nature rash. Lasts from one to two weeks, gradually turning pale. After flowering rash, the skin begins to flake.
The characteristic can be called a symptom Filatov – bright red skin nasolabial triangle remains white.
Early in the disease, especially at high temperatures, heart rate increased, pulse frequent, arterial pressure slightly increased. Then, with the second-third week, there is a decrease in rate is below normal, heart tones become deaf ("skarlatines heart"). This is due to excessive activation of the parasympathetic nervous system.
Boys and girls differences in clinic and complications have been identified.
On the severity emit:
- Easy form is characterized by slight fever, mild intoxication. Rash pale, takes place over four days. Recovery occurs a week later.
- Medium is manifested by increased body temperature to 400 bright distinct rash. Severe intoxication is accompanied by vomiting, insomnia. Children worried about angina. The symptoms resolve in two to three weeks.
- Heavy temperature above 40oC, all the symptoms of bright expressed. Due to intoxication may occur stun. In the tonsils foci of necrosis. With otitis media, sinusitis or other foci of streptococcal infection. How dangerous scarlet fever of a severe form? The development of infectious-toxic shock or sepsis.
Complications
Suppurative complications: otitis, sinusitis, erysipelas, etc.
When sensitization to beta-hemolytic Streptococcus may develop glomerulonephritis, myocarditis, rheumatic fever. To prevent their development, treatment should start as early as possible.
Diagnostics
In blood the number of lymphocytes due to their neutrophil fraction, increased erythrocyte sedimentation rate. In the General analysis of urine find traces of protein, hyaline casts, red blood cells.
Identification of the pathogen
If you suspect scarlet fever from the oropharynx in children take the swab and do the sowing, and then study the resulting colony. To assign the most appropriate treatment, it carried out a test of tolerance to antibiotics. Serum seeing an increase in the titer of antibodies to streptococcal antigens.
Treatment
Mild and moderate are treated at home. Prescribe bed rest, sparing diet and drinking plenty of fluids. Treatment antibiotic penicillin. The ineffectiveness of the pediatrician selects the other. For the relief of symptoms of sore throat use gargle Furacilinum or other antiseptics in the home, you can prepare a decoction of chamomile, oak bark. If it is impossible to isolate children or severe currents require hospitalization.
After the transfer of scarlet fever children are subject to medical examination within one month after mild and moderate forms and three – after a hard.
Prevention
To prevent the spread of infection in the team,the sick are isolated. For a group of kindergarten, where the disease was found, being quarantined for seven days. During this period, children are examined by a pediatrician. Those who have a temperature or redness of the oropharynx, isolated at home. All contact is prescribed preventive treatment – gargling with antiseptics. Indoor group conduct disinfection.