Tularemia ( epidemic lymphadenitis ) - Causes, Symptoms and Treatment .MF .

August 12, 2017 17:52 | Infectious Diseases

Tularemia (chumopodobnaya disease, rabbit fever, a small plague, fever of deer flies, mouse disease epidemic lymphadenitis) - acute zooantrapanoznaya natural focal bacterial infection with multiple mechanisms of transmission, characterized by feverish intoxication syndrome, inflammatory changes in the entrance gateinfections, and regional lymphadenitis.

disease first established in 1911 in California, when McCoy and Chepii discovered chumopodobnoe disease in ground squirrels, identified the causative agent and called it Bacterium tularense (at the place of the epizootic in Tulyare lake district).Later found the predisposition of the disease in humans, and even after some time to learn about the scale of prevalence: in the whole area of ​​North and Central America, on the Eurasian continent.Generally, it is believed that the disease is where rodents proliferate actively.

causative agent of tularemia

Francisella tularensis - Gram stick (ie, painted in pink color) and this color indicates the presenc

e of the capsule, hence the vulnerability of a phagocyte in contact in the macro-organism.Controversy and flagella has.Also, there are other features of the structure of the pathogen, which create particular symptoms:

• neuraminidase facilitates adhesion (fixation) to the damaging tissues;
• endotoxin causes a feverish intoxication syndrome and allergenic properties of the cell wall;
• ability to multiply in phagocytes and suppress their killer effect;
• The presence of receptors for Fc-fragments of the immunoglobulin class G (IgG), thus is disturbed complement system activity and macrophages.

last two factors lead to the restructuring of an allergic immune system

Pathogen relatively stable in the environment (despite the lack of sporulation), especially at low temperature and high humidity: survives «-300 ° C" in the ice - up to 10 monthsin frozen meat to 3 months in water - more than a month (and at 10 ° C - 9 months), in rodent secretions from patients - more than 4 months in soil - 2.5 months, in the milk - 8 days at a temperature20-30 ° C - up to 3 weeks.

causative agent is sensitive to the following factors:

• high temperature - 60 ° C are killed within 10 minutes;
• direct UVB - are killed within 30 minutes;
• detrimental effect of ionizing radiation and disinfectants (Lysol 3%, 50% alcohol, formalin, chloramine, bleach, corrosive sublimate) - innaktivatsiya pathogen occurs after 10 minutes.

susceptibility of people to tularemia high and reaches 100%, that is, each kontaktivovavshy a pathogen falls ill, with no sex and age restrictions.There the summer-autumn season.Natural focal prevalence - natural foci of tularemia exist on all continents of the northern hemisphere, in Western and Eastern Europe, Asia and North America.On the territory of the Russian Federation registered the disease everywhere, but mostly in North, Central and West Siberian regions of Russia.

Causes infection tularemia

Source - about 150 species of vertebrates (105 mammals, 25 species of birds, some aquatic life), but the pride of place occupied by rodents detachment (vole, water rats, house mice, rabbits), at the thief location - livestock(sheep, pigs and cattle).

transporter - blood-sucking insects (ticks and gamasid ticks, mosquitoes, horseflies).transmission mechanisms: contact (at direct contact with infected animals or their biological materials), contact-consumer (when the infection waste of infected animals household items), alimentary (in the use of contaminated food), transmissive (the bite of infected blood-sucking), aerogenic (atinhalation of contaminated dust).

In the human pathogen gets through microtrauma of the skin, mucous undamaged tonsils / oropharyngeal / GI / airways / eye and possibly genitals.Moreover, the need for only minimal contamination infectious dose and at a given dose of this disease is a microbial cell (in, while in other infectious diseases - 10'⁵ or more)!

Symptoms of tularemia

The incubation period (time from the beginning of the introduction of the pathogen to the onset of symptoms) - 2-8 days, but sometimes delayed up to 3 weeks.During this period, fixation and reproduction of the pathogen at the site of the entrance gate, and as soon as the number of agent reaches a certain concentration, there is a period of clinical manifestations.

period of clinical manifestations characterized by both local and general symptoms.Local changes - inflammatory and necrotic reactions at the site of pathogen ingress, with the formation of primary affect (skin ulcer, passing stage papules, vesicles and pustules, if the initial contact took place on the tonsils - necrotic angina, in the lungs - a focal necrotizing pneumonia, the conjunctiva - conjunctivitis).

But local reactions occur and evolve in parallel with the general, namely, regardless of the form of the disease (anginal, abdominal or lung), note the acute onset of the disease (like prodrome, lasting 2-3 days) - with feverish intoxication syndrome(temperature rises to 38-40 ° C and above, headache, dizziness, weakness, sweating, loss of appetite, bradycardia, hypotension).

Obscheintoksikatsionnye symptoms due to the fact that part of the pathogens remain in the gate of infection and forms the primary focus, and a part - is distributed by lymphatic and hematogenous routes.After fixing, the agent enters the lymphatic vessels and reach regional lymph nodes, where he freely propagated and thus in lymphoid tissue is formed by swelling and forms a "bubo" (as in plague), then the pathogen enters the bloodstream and causes bacteremia, bloodstream is carried inorgans and tissues, causing granulomas formed therein and necrotic ulcers, a variety of symptoms are formed.

But the variability of clinical forms depends mainly not on the affected organ, and from the place of the entrance gate, under which distinguish the following clinical forms of tularemia:

• ulcerative glandular (bubonic),
• eye-ferrous (conjunctivitis);
• anginal-glandular;
• abdominal;
• lung.

After the onset of bacteremia and organ infection occurs during the crisis period, characterized not only feverish intoxication syndrome (duration of heat reaches a month!), But also a variety of other symptoms with the same frequency of occurrence:

- the appearance of patients is very characteristic: puffyand congested face, possibly with a bluish tint around the eyes / lips / earlobes, around the chin - pale triangle injection vascular sclera, petechial hemorrhages in the mucosa of the oropharynx, erythematous / or papular / or petechial hemorrhage leaving behind a peeling and pigmentation

- lymphadenitisdifferent localization.In the event of a bubo (lymph node is very large - from walnut to 10 cm in diameter) - talk about the bubonic form, which occurs when transmesivnyh mechanisms of infection, localization often - thigh, groin, elbow, armpit and around the lymph node is formed konglamerat s at signsperiadenita.There bubo 2-3 days after the onset of clinical manifestations and reaches its dawn to the 5-7 day, with a gradual increase in local changes: first, the skin over the lymph node is not changed, but over time there is a reddening + increases the cohesion of the lymph node with skin and surrounding tissues+ increases the soreness.The outcome of this bubo may be different - from the traceless resorption, to suppuration with fluctuation and subsequent scarring (in this case, filled with plum bubo pus, which dissolves and heals a few months, leaving a scar).

bubonic with tularemia

- when Ulceroglandular form - also occurs lymphadenitis, but with skin changes in infection gates that come to the fore - in a place of introduction formed primary affect, which passes through the stages from the spot - papules- pustules - small painless ulcer (5-7mm) with podrytymi edges and scarce serous-purulent discharge and heal the plague in 2-3 weeks, leaving a scar.This form occurs when a vector-borne, and in a contact / contact-household transmission mechanisms.The usual localization - exposed parts of the body (neck, upper arm, thigh).

- when anginal-bubonic FORM lymphadenitis takes the second place, and comes to the fore sore throat with some features: redness of the tonsils with a bluish tint, and puffiness, grayish-white ostrovchaty or plёnchaty Deposits - difficult to remove and therefore it can be confused with diphtheria filmsbut unlike the latter, when the film tularemia do not go beyond the tonsils.A few days later, under these raids are formed slowly healing ulcers (in rare cases may occur before the film).This form occurs when the alimentary infection, this form may join in the future and abdominal shape.

- Abdominal (gastrointestinal) - the rarest but most severe form.The clinic is highly variable: cramping or aching pain, spilled or localized, tongue coated gray-white coating and dryish, dyspepsia (possible constipation and stool softener)

- GLAZOBUBONNAYA form occurs by ingestion of the pathogen through the conjunctiva by contaminated hands highair obsemenёnnosti - ie by inhalation of dust.In this form of conjunctivitis occurs (usually unilateral), with a strong watery eyes and swelling of the eyelids, severe swelling of the transitional fold, muco-purulent discharge, the presence of yellowish-white nodules on the mucous membrane of the lower eyelid.This increases the regional lymph nodes - BTE, submandibular, perednesheynye.

- pulmonary form (thoracic) infection occurs when airborne droplets and can occur either bronhiticheskoy, or pneumonic form.When bronhiticheskoy form - a dry cough, chest pain, breathing hard and dry wheezing.This form is more lightweight than the pneumonic and clinical recovery occurs within 2 weeks on average.

Diagnosis of tularemia

Diagnosis is based on epidemiological, clinical and laboratory data.When epidissledovanii establish a connection and timing between the clinic and the recent departures.Because of the vastness and stёrtosti symptoms, clinical data provide little information.

Laboratory data are a wide range of:

- OAK: normotsitrz or leukocytosis (↑ LC), neyrotsitoz (↑ Hf) ↑ ESR.At the height - A ^ ↓, ↑ Lf and M. When festering bubo - leukocytosis.

- Serological methods: RA (agglutination) and HAI (hemagglutination) - determination of titers of antibodies and antigens of 1: 100, and the earliest method - PHA, and RA can detect an increase in antibody titer from 10-15 days, a second study carried outa week later and, if title is not changed, or they are not found, re-conducted study after another nedёlyu and increase in antibody titer of 2-4 times make a diagnosis of tularemia eligible.ELISA (enzyme-linked immunosorbent assay) - more sensitive than all other serological methods in 20 times, but it is advisable to apply a 6 days and decrees, this method for the detection of specific antibodies - of IgG and the M, by which determine the stage of disease: because in the presence of IgM speak about acute processor the height of the stage, while the presence of IgG - suggests a later date from the time of infection and indicates a good immune response.

- Allergic method - using a skin allergy test, which differs strict specificity and carried out with 3 days of illness, and therefore referred her to an early diagnostic methods.Held as a Mantoux test, but instead of tuberculin injected tulyarin in the middle of the forearm, and evaluate the results at the end of the first day, on the second and on the third, measuring the diameter of infiltration: infiltration if a diameter greater than 0.5 cm - test is positive if the redness disappears at the end of the first day- negative.If there are contraindications for setting skin test, spend as allergic method, but in vitro (ie in a test tube and look at the reaction leykotsitoliza).

- Bacteriological method is aimed at detecting the pathogen in the biological substrates, but it can be carried out only in specially equipped laboratories, because vysokokontagiozen pathogen (infectious), because this analysis is assigned to patients is rare.

- PCR (polymerase chain reaction) - genetic method aimed at the detection of pathogen DNA, is informative in the fever period, so it is as well as allergic method referred to as an early diagnostic.

Treatment of tularemia

Treatment begins with respect for the ward mode in which windows close mesh to prevent transmissible transmission mechanism + strict observance and monitoring of sanitary regulations (current disinfection with 5% phenol solution, a solution of mercuric chloride and other disinfectants).

• Causal treatment is aimed at destruction of the pathogen by the use of antibiotics and tetracycline aminoglikozidovogo.If you have an allergy to aminoglycosides, as an alternative to the use of III generation cephalosporins, rifampicin, chloramphenicol, fluoroquinolones are used in age-related doses.Streptomycin - in the national leadership of infectious diseases when they write about the applicability of tularemia, but try to resort to it rarely and only in the hospital, because it blocks the neuromuscular conduction, followed by respiratory arrest.Gentamicin - 3-5 mg / kg / day for 1-2 Hour, Amikacin - 10-15 mg / kg / day in 2-3 hours.Tetracycline prescribed for bubonic and ulcerative bubonic form;Do not prescribe them to children under 8 years old, pregnant women, patients with decompensated by the kidneys and liver.The course of 10-14 days of antibiotics.

• Local therapy - for skin ulcers and bubonic, is the application of antiseptic dressings, quartz, blue light and laser irradiation.When festering bubo -hirurgicheskoe intervention, which consists in opening the bubo wide incision to drain the pus from it.

• Patoneneticheskaya therapy is the appointment of detoxification, antihistamine, anti-inflammatory drugs, vitamin complexes and cardiac glycosides - indicated.Also, be aware of the prevention of the use of antibiotics dizbakterioza - administered pre / probiotics and not only orally, but also rectally, unnecessarily as it passes through the digestive tract, bifidum and lactobacillus perish in an acidic environment of the stomach.

Complications tularemia

• Immune system - allergic reactions, IDS (immunodeficiency);But because it is the specific target organ is not, there is no specific clinics, and therefore no specific complications, but there is a common (possibly due to infection gate) ITSH (infectious and toxic shock syndrome), meningitis, pericarditis, myocardial dystrophy,arthritis, peritonitis, perforation of the cornea, bronchiectasis, pulmonary abscesses and gangrene.

tularemia

Prevention Prevention is divided into specific and nonspecific.Specific - use of live dry tularemia vaccine for children over 7 years old residing in the endemic tularemia areas, assess the condition of immunity serum samples of 5 (7) and 12 (15) a day, for 5 years, and 1 time in 2 years, whennegative performance is carried revaccination.

Nonspecific prevention is control of natural foci, early detection of outbreaks of disease among wild animals, carrying out deratization and disinfestation.

At the outbreak of water - Do not swim in the water and drink unboiled water.Apply specialized clothing when in contact with sick animals or when in their habitats.

Medical consultation:

Question: Is it necessary to open the vesicle to the site of the bite?
The answer is no.

Q: Saved immunity after the disease?
yes, it resistant, durable, life;Has the nature of the cell (due to T-lymphocytes, macrophages, and antibodies), phagocytosis immunized is the completed character, in contrast to the infected.

therapists Shabanova I.E