Brucellosis

The causative agent of the disease is a group of microorganisms of the genus Brucella . There are three pathogens for humans: the causative agent of brucellosis of small cattle ( Brucella melitensis ), the causative agent of brucellosis of cattle ( Brucella abortus ), the causative agent of pig brucellosis ( Brucella suis ) ^[4] all of them are named after the English microbiologist David Bruce . Brucella are very small, motionless, do not form spores, but under certain conditions they can form a capsule. Polymorphism of microbial cells is characteristic - in one preparation you can find coccal, ovoid and rod-shaped forms. They are easily stained with all aniline dyes, gram-negative. ^[five]

The causative agents of brucellosis are small bacteria, immobile, do not form spores. They are stained with all aniline dyes, gram-negative. They grow on ordinary nutrient media, mainly on hepatic agar, on media supplemented with glucose and glycerin. They are able to parasitize intracellularly. There are 6 known types of pathogens of brucellosis and 17 biovars. The source of brucellas dangerous to humans are mainly 4 types: goats , sheep (Br.melitensis), cows (Br.abortus bovis), pigs (Br.abortus suis) and dogs (Br.canis), which excrete the pathogen with milk, urine, amniotic fluid, moreover, autumn carrier (Stomaxys calcitrans) is the carrier of brucellosis. Human infection occurs through direct contact with animal carriers or when eating contaminated products, such as raw milk, cheese made from unpasteurized milk.

In the external environment, brucella remains viable for quite a long time: in the soil - up to 100 days or more, in dust - up to 44 days, in water 6-150 days, in salted meat - 80-100 days. At low air temperatures, brucellas do not lose viability up to 160 days or more. In a dry environment, brucella die in 1 hour at a temperature of 90-95 degrees, in a humid environment at a temperature of 55 degrees Celsius in 1 hour, at 60 degrees in 30 minutes. Boiling kills brucella instantly.

Gates - microtraumas of the skin, mucous membrane of the digestive system and respiratory tract. There are no changes in the place of the gate and in the lymphatic paths of the regional lymph nodes. Lymphadenopathy with brucellosis is generalized, which indicates hematogenous dissemination of microbes. Reproduction and accumulation in the lymph nodes - periodically in the blood. Severe allergic restructuring of the body, pronounced delayed-type hypersensitivity persists for a long time after cleansing the body of the pathogen. Brucellosis is prone to a chronic course. Immunity is formed, but not prolonged (reinfection is possible after 3-5 years). The appearance of brucellosis is also significantly affected by the type of brucellosis that caused the disease. The most severe course of brucellosis is melitensis, the rest cause milder forms.

When examined under a microscope of organs and tissues affected by brucellosis, characteristic granulomas are seen, very similar to tuberculosis , rarely, however, undergoing caseous necrosis . An exception is B. suis infection, in which abscesses are often observed.

In patients with brucellosis of bulls, rams, boars, purulent necrotic orchitis and epididymitis are found. With a section of enlarged testes, foci of necrosis and ulcers are visible. ^[6]

The incubation period is 1-2 weeks. The disease develops, as a rule, gradually and does not have specific features. But patients usually present four main complaints:

• moving pain in the joints, mainly in the lower extremities, sometimes very strong and painful.
• increase in body temperature in the form of prolonged subfebrile condition (up to 38 ° C) or wave-like type with sharp rises and falls.
• excessive sweating, sweating, sometimes night sweats.
• sharp weakness and breakdown.

Systemic lesions are manifold and affect almost all organs. Meet:

• Musculoskeletal system

septic monoarthritis , asymmetric polyarthritis of the knee, hip, shoulder sacroilial and sternoclavicular joints, spinal osteomyelitis , myalgia.

• A heart

endocarditis , myocarditis , pericarditis , an aortic root abscess , thrombophlebitis , and endocarditis can also develop on previously unchanged valves.

• Respiratory system

bronchitis and pneumonia .

• Digestive system

anicteric hepatitis , anorexia and weight loss.

• Genitourinary System

epididymitis , orchitis , prostatitis , tubo-ovarian abscess , salpingitis , cervicitis , acute pyelonephritis .

• central nervous system

meningitis , encephalitis , meningoencephalitis , myelitis , cerebral abscesses, Guillain-Barré syndrome , optic atrophy , defeat of pairs III, IV and VI.

• Lymph nodes, spleen

lymphadenitis, enlarged spleen

• Eyes

keratitis , corneal ulcers , uveitis , endophthalmitis .

The approximate frequency of the history and some symptoms / complaints in patients with brucellosis (in%)

N.I. Ragosa distinguishes 4 phases: the phase of compensated infection (primary latent), the phase of acute sepsis without local lesions (decompensation), the phase of subacute or chronic recurrent disease with the formation of local lesions (decompensation or subcompensation) and the phase of restoration of compensation with residual effects or without them.

Clinical forms of brucellosis:

1. Primary latent form;
2. Acute-septic form;
3. Primary chronic metastatic form;
4. The form is secondary chronic metastatic;
5. The form is secondary latent.

Primary latent state of practical health. With the weakening of protective forces, it can turn into either an acute-septic or a primary chronic metastatic form. Sometimes microsymptoms: a slight increase in peripheral lymph nodes, sometimes the body temperature rises to subfebrile, increased sweating during physical exertion. They consider themselves healthy and remain healthy.

The acute-septic form is fever (39–40 ° С), the temperature curve is wavy, of an irregular (septic) type with large daily ranges, repeated chills and sweats. She feels good (at a temperature of 39 ℃ and above, she can read books, play chess, watch TV). There are no other signs of general intoxication. It does not threaten the patient’s life, even without etiotropic treatment, it ends in recovery. All groups of lymph nodes are moderately enlarged, some are sensitive. By the end of the first week - an increase in the liver and spleen. In the study of blood leukopenia, ESR is not increased. The main difference is the absence of focal changes (metastases). Without antibiotic therapy, the duration of fever is 3-4 weeks or more.

Chronic forms sometimes develop immediately, bypassing the acute, sometimes after a time after the acute-septic form. According to the clinic, the primary chronic metastatic and secondary chronic metastatic forms do not differ. The difference is the presence or absence of an acute-septic form in the anamnesis. Clinic: prolonged low-grade fever, weakness, increased irritability, poor sleep, impaired appetite, decreased performance. Generalized lymphadenopathy is mild, sensitive, or painful on palpation; small, very dense, painless, sclerosed lymph nodes (0.5-0.7 cm in diameter) are noted. Enlarged liver and spleen. Against this background, organ lesions are detected, most often from the musculoskeletal system, followed by the nervous and reproductive systems. Pain in the muscles and joints, mainly in large ones, polyarthritis, with a new exacerbation, other metastases localize. Periarthritis, paraarthritis, bursitis, exostosis, osteoporosis is not observed. The joints swell, their mobility is limited, the skin above them is normal in color. Mobility impairment and deformation are caused by overgrowth of bone tissue. The spine is affected, more often in the lumbar. Sacroileitis is typical (Eriksen symptom: on the table on the back or on the side and pressurize the crest of the superior ilium in the lateral position or squeeze the front superior iliac crests in the supine position with both hands. In case of unilateral sacroileitis of pain on the affected side, with bilateral pain in the sacrum from two sides). Symptom Nakhlasa, lay on the table face down and bend the legs at the knee joints. When lifting a limb, pain in the affected sacroiliac joint. Symptom Larrey on the table on his back, the doctor takes with both hands the protrusions of the wings of the ilium and stretches them to the sides, while there is pain in the affected side (with unilateral sacroileitis). Symptom of John — Bera: the patient is in a supine position, with pressure on the pubic joint, pain in the sacroiliac joint is perpendicular downward.

Myositis of pain in the affected muscles. The pains are dull, prolonged, their intensity is associated with changes in the weather. On palpation, more painful areas are determined, and painful seals of various shapes and sizes are felt in the thickness of the muscles. Fibrositis (cellulitis) in the subcutaneous tissue on the legs, forearms, back and lower back. Sizes from 5-10 mm to 3-4 cm are soft oval formations, painful or sensitive. In the future, they decrease, can completely dissolve or sclerosize and remain for a long time in the form of small dense formations, painless.

Damage to the nervous system: neuritis, polyneuritis, radiculitis. Damage to the central nervous system (myelitis, meningitis, encephalitis, meningoencephalitis) is rare, lasts a long time and is difficult.

Changes in the reproductive system in men - orchitis , epididymitis , decreased sexual function. In women, salpingitis , metritis , endometritis . Amenorrhea occurs, infertility may develop. Pregnant women often experience abortions, stillbirths, premature births, and congenital brucellosis in children.

Secondary chronic form proceeds in the same way. The secondary latent form differs from the primary latent in that it more often passes into manifest forms (recurs).

• Acute - lasting up to 3 months;
• subacute - lasting 3-6 months;
• chronic - more than 6 months.

• Anamnesis data: contact with animals, eating thermally unprocessed livestock products, patient's specialty, endemic foci.
• The clinical picture .
• Laboratory diagnosis:
  • Blood culture on culture media is positive in 50–70% of cases in patients with brucellosis:
  • Wright's reaction is positive on the 10th day;
  • Coombs reaction - the diagnosis of chronic brucellosis;
  • 2-mercaptoethanol-agglutinite test;
  • Headdleson reaction ;
  • Burne's skin test ;
  • detection of Brucella spp. DNA. nucleic acid amplification methods ( PCR ).

Brucellosis rarely causes death. Even before antibiotics appeared, mortality with it did not exceed 2% and was mainly due to endocarditis . However, brucellosis often ends in disability. The severity of residual defects depends on the type of pathogen. The most severe consequences are caused by brucellosis caused by Brucella melitensis . One of the causes of disability is neurological disorders, including spinal cord injury and paraplegia . Sensory hearing loss is described as a complication of meningoencephalitis and streptomycin treatment.

Antibiotic therapy : two, three drugs of the following: tetracycline , streptomycin , doxycycline , rifampicin , gentamicin - only in acute brucellosis, in combination with drugs that penetrate intracellularly, biseptol , netilmicin . Fluoroquinolones ( ciprofloxacin , norfloxacin , ofloxacin ) are most effective in treating brucellosis in humans, the most effective of them is fleroxacin. Anti-inflammatory drugs (indomethacin, brufen) Detoxification therapy (methionine, adenazine triphosphate) Antihistamines Vitaminoterpia (B6, B12) Immunotherapy (dibazole, pentoxyl, thymalin)

Possible schemes:

• Doxycycline 45 days + streptomycin or gentamicin 14 days
• Doxycycline + netilmicin (mentioned by some authors as the most effective regimen)
• Doxycycline + rifampicin
• Fluoroquinolones + Doxycycline , or Netilmicin , or Rifampicin
• Fluoroquinolones in monotherapy
• Trimethoprim / Sulfamethoxazole ( Biseptol ) + Rifampicin

Brucellosis becomes chronic in 37-80% of cases, especially with untimely or inadequate treatment.

• Pasteurization or boiling milk
• Veterinary supervision of animals
• Sanitary and hygienic education of the population working with animals or their products
• Preventive vaccinations in high-risk individuals (short period of action - about 2 years)
• Massive preventive vaccinations of animals did not give the expected result

The disease has been known since the time of Hippocrates. In the 18th century, it was often described under the names of Maltese, Cretan, Mediterranean, undulating fever. In 1887, the English physician Bruce discovered the microbe causative agent of Maltese human fever. Goats were the source of infection for humans. ^[6]

• Infectious Diseases Handbook, prof. L. A. Trishkova, Assoc. S. A. Bogatyreva
• Handbook of differential diagnosis of infectious diseases. Edited by Professor A. F. Frolov, Professor B. L. Ugryumov, Dr. med. Sciences E.K. Trinus. Kiev
• Kozlov M.P. Epidemiology of brucellosis in the Ciscaucasia: author. dis. Cand. honey. sciences. - M., 1962 .-- 23 p.

• Harrison's Principles of Internal Medicine, 14th Edition, McGraw-Hill, Health Professions Division
• ΕΣΩΤΕΡΙΚΗ ΠΑΘΟΛΟΓΙΑ ΑΠΘ, ΤΜΗΜΑ ΙΑΤΡΙΚΗΣ-ΤΟΜΕΑΣ ΠΑΘΟΛΟΓΙΑΣ, ΔΙΕΥ / ΤΗΣ: ΚΑΘΗΓΗΤΗΣ Μ.ΠΑΠΑΔΗΜΗΤΡΙΟΥ

• https://web.archive.org/web/20070309020656/http://www.cbwinfo.com/Biological/Pathogens/BM.html
• https://web.archive.org/web/20070113231531/http://www.aphis.usda.gov/vs/nahps/brucellosis/
• https://web.archive.org/web/20160417045047/http://www.cdc.gov/NCIDOD/DBMD/DISEASEINFO/brucellosis_g.htm
• https://web.archive.org/web/20070205105419/http://www.hpa.org.uk/infections/topics_az/zoonoses/brucellosis/gen_info.htm
• http://www.emedicine.com/emerg/topic883.htm
• http://www.wrongdiagnosis.com/b/brucellosis/intro.htm
• College of Veterinary Medicine. The university of georgia
• Department of Health
• Brucellosis
• International Workshop at SIC TBP (Serpukhov District)
• Brucellosis Sanitary rules SP 3.1.085-96 Veterinary rules VP 13.3.1302-96 (inaccessible link)
• All-Russian Research Institute of Brucellosis and Animal Tuberculosis of the Russian Academy of Agricultural Sciences