Tularemia

Tularemia

Tularemia is an acute infectious natural focal disease of a group of bacterial zoonoses, characterized by intoxication, fever, and lesions of the lymph nodes. Etiology. The causative agent is small immobile gram-negative coccobacilli Francisella tularensis. Epidemiology. Natural reservoir – house mice, voles, water rats, muskrats and hares. A person becomes infected from sick animals, blood-sucking arthropods. Ways of infection – contact, inoculative (with a vector bite), alimentary and inhalation.

Classification and clinical picture

• • The onset of the disease is acute and similar in all forms. Characterized by chills, high body temperature, persistent headache, muscle pain. Pastosity and hyperemia of the face, conjunctiva, mucous membrane of the mouth and nasopharynx, injection of the sclera are noted. Most have regional lymphadenitis, some (more often with a protracted course) have a rash in the form of erythema, roseola, petechiae or papules, sometimes in symmetrical areas (socks, stockings, gloves, etc.). The rashes persist for 8-12 days, after which peeling and pigmentation remain. From 3-5 days dry cough appears. From the first days of the disease, an increase in the liver is noted, and from 6-9 days – an increase in the spleen. In the urine: moderate albuminuria, cylindruria and hematuria. In the blood – leukocytosis and an increase in ESR.
  • bubonic form. The primary bubo is formed on the 2nd-3rd day of the disease. Axillary, cervical and submandibular buboes are more often observed. The lymph node is a little painful, has clear contours. With suppuration, traditionally after 2-4 weeks, the bubo opens with the separation of thick creamy pus.
  • The ulcerative-bubonic form develops as a result of transmissible transmission. At the site of an insect bite, a papule appears, turning into a shallow ulcer.
  • The anginal-bubonic form is observed with the alimentary route of infection. Starting from 4-5 days, hyperplasia of the tonsils, grayish-white plaques (usually unilateral) are noted. Necrotic processes gradually develop and deep slowly healing ulcers are found.
  • Abdominal form: characterized by severe abdominal pain, vomiting, flatulence, stool retention, and sometimes diarrhea. Sometimes you can palpate enlarged mesenteric lymph nodes.
  • The pulmonary form occurs with symptoms of bronchitis or pneumonia.
  • Generalized form: characterized by a severe typhoid-like or septic course in the absence of a primary lesion and regional lymphadenitis. Possible complications are secondary tularemia pneumonia, cavern formation, meningoencephalitis, peritonitis, pericarditis, myocardial dystrophy.

Research methods

• • Isolation of the pathogen. Cultivation of the pathogen is associated with a threat of infection of personnel and is allowed only in laboratories of especially dangerous infections.
  • In the absence of the probability of isolation of the pathogen, laboratory animals (mice or guinea pigs) are infected with pathological material (bubo biopsy material, pharyngeal mucus, purulent discharge of the mucous membrane of the eye, blood, etc.) with subsequent identification of the microbe by agglutinating serum. Material from the bubo should be taken up to 14-20 days of the disease, from the mucous membrane of the eye – up to 17 days, blood – up to the 6th day of the disease.
  • The presence of AT to the pathogen in the patient’s serum is determined in the agglutination test with tularemia diagnosticum. A reaction visible to the eye is considered positive when the serum is diluted 1:100 or more (positive results for 1 week are detected in 12.5% ​​of patients, for 4 weeks – in 93.2%). Express diagnostics is possible, based on the identification of antigen in smears from AT lesions labeled with fluoresceins
  • For early diagnosis, an allergic skin test (Foch test) is used. As Ag, tularin is used (a suspension of bacteria killed by heating to 70 ° C). The drug is injected intravenously in a volume of 0.1 ml (100 million microbial bodies), the account is made after 24-48-72 hours. The test is also positive in people who have had tularemia.

Differential Diagnosis

• • Bubonic and ulcerative bubonic forms
  • Venereal lymphogranuloma
  • pasteurellosis
  • cat scratch disease
  • Sporotrichosis
  • Plague
  • Generalized form
  • Typhoid fever
  • Infectious mononucleosis
  • salmonellosis
  • Brucellosis
  • Q fever
  • ornithosis
  • Yellow fever
  • Borreliosis
  • Tick-borne typhus
  • Viral pneumonia
  • Oculo-bubonic and anginal-bubonic forms
  • Streptococcal pharyngitis
  • Viral pharyngitis
  • Diphtheria pharyngitis
  • Infectious mononucleosis.

Treatment:

Surgery. Opening and drainage of abscesses. Drug therapy

• • The drug of choice is streptomycin 15–20 mg/kg/day IM for 7–14 days
  • Alternative Products
  • Tetracycline nbsp; 1.5 g / day
  • Levomycetin2 g/day
  • Ciprofloxacin 250–500 mg/day orally
  • Aminoglycosides
  • Antibiotic therapy is continued for 5 days after the normalization of body temperature.

Complications

• • lung abscess
  • Respiratory distress syndrome
  • Liver damage
  • Rhabdomyolysis
  • kidney damage
  • Osteomyelitis
  • Meningitis
  • Endocarditis
  • Pericarditis
  • Peritonitis
  • Mediastinitis.

Current and forecast. With timely and adequate treatment, a full recovery. With a generalized form, mortality reaches 3%.

Prevention

• • Mass immunization with live vaccine. The need for revaccination after 5 years in an unfavorable epidemiological situation is established by a skin test with tularin. Mandatory vaccination is subject to the population of endemic areas and employees of specialized laboratories
  • General measures: extermination of rodents, ticks, ensuring a satisfactory sanitary condition of water sources, food depots, etc.

Synonyms

• rabbit fever
• Deer fly fever
• Small plague
• Bacterial tularemia
• tick fever
• Ohara’s disease
• Francis ICD disease. A21 Tularemia Literature. 129:264-265