Brucellosis in humans
What is brucellosis?
Brucellosis is a zoonotic infectious disease caused by pathogenic microorganisms of the families of Brucella, and is characterized by indolent inflammatory process in all organs and tissues, mainly affecting the lymphatic, osteoarticular and nervous systems.
Classic medium circulation of the causative agents of the disease are domestic animals (cows, goats, horses, pigs rarely). There are several types of Brucella that primarily striking every species of these animals. People in varying degrees susceptible to any of the types of Brucella infection, which contributes to the spread of the disease among people who are engaged in agricultural activities and animal husbandry. The possibility of developing brucellosis and its specific forms among people is determined by the activity of the immune system and the virulence of pathogens.
Brucella represent organisms with a polymorphic structure (cocci, small sticks) and moderate virulent pathogenic properties. They are very resistant in the external environment that plays an important role in their possible dissemination and circulation among susceptible organisms. Infected raw milk and meat they are able to survive about 3 months. Killed at pasteurization and heat treatment at higher temperatures for several minutes. Not produce exotoxins. Pathogenicity is due to antigenic components of the cell wall that are released into the blood during the destruction of the Brucella immune cells.
The infection of human brucellosis occurs in the way:
When consuming milk and meat of infected animals, or containing viable Brucella pathogens;
In contact with human skin of Brucella from the hair of cattle;
Inhalation of Brucella with dust or particles of wool.
Once in the human body, Brucella quickly and actively in the intercellular space and the lymphatic ducts, where the captured cells from the immune system macrophages. This moment of the pathogenesis of brucellosis is a Central element in the duration of the course of the disease, which can last for years. The intracellular location of pathogens along with their low antigenic activity does not allow the body to fully destroy them because of the need to destroy the body's own cells.
The first focus of an accumulation and reproductionBrucella pathogens become regional in relation to the place of the introduction, lymph nodes. Of these, the pathogens are periodically released into the bloodstream and spread to organs consisting of reticular tissue: liver, spleen, bone marrow of long bones. After breeding cycles in these tissues is the release of young of Brucella in the blood with the defeat of new cells organs and infection macrophages in the joints and nervous tissue (the spinal cord). Untreated, the process becomes sluggish for long.
The symptoms of brucellosis in humans
The clinical picture in brucellosis nonspecific, as it captures a lot of the symptoms that gradually joined to each other. Depending on this, there are acute, chronic or residual form of the disease. Their symptoms are almost identical, differing only in their degree of severity and activity of inflammatory-infectious process.
Stages of the growth of the clinical picture of brucellosis can be traced to different symptoms:
- Fever. Shows the temperature reaction in the form of hyperthermia to 38-39,7°C. As a rule, such jumps are observed periodically and coincide with periods of release into the bloodstream of pathogens from lesions of the affected organs. In the periods between maximum temperature increase in acute brucellosis remains a low-grade fever, and in chronic process, the temperature may be normal.
- Chills and sweating on the background of febrile seizures. The classic triad of acute brucellosis. Paradoxically, despite the high temperature, intoxication and disturbance of the General condition are virtually absent.
Lymphadenopathy. Presented an increase, primarily, one group of lymph nodes regional order. Chronic and lingering acute forms of brucellosis are characterized by a gradual involvement of different lymphatic collectors, which is manifested by increases throughout the body.
Hepatosplenomegaly. With 2-3 weeks of the febrile period when the acute process is increase in size of liver and spleen. This is due to sluggish inflammation that occurs in response to the introduction of pathogens. In parallel with the immune cells destroy normal tissue.
- Inflammatory processes in the genital organs. In this respect, we are talking aboutmen. Most often affects the testicles, which manifests the typical one - or bilateral orchitis. This manifestation of the disease caused by high activity of the blood flow in germ cell tissues of these organs, where Brucella delayed, passing through the hemato-testicular barrier.
Signs of Central nervous system. Manifest as headache, meningeal symptoms, irritability and emotional lability, autonomic disorders (irregular heartbeat, sweating, changes in blood pressure, feeling of heat or cold).
Bone and joint pain. Occur almost always during the long-term brucellosis, accompanying each of his aggravation. As a rule, due to the addition of a secondary Brucella arthritis. Affects one of the large joints, usually the knee, in the form of swelling, pain, disturbances of the support on the injured limb.
- Radicular syndrome. Is characterized by the occurrence of sweep or constant aching back pain on the type of lumbodynia. Increases with load and torso twists. Refers to the criteria of the chronic and prolonged course of the disease.
The signs of the residual process. Characterized by deformities of the joints, stiffness, curvature of the spine, osteoporosis, the violation of the structure of internal organs, neurological disorders, skin rash, and granulomatous cells in the skin of the extremities, hands.
Diagnosis of brucellosis
To diagnose brucellosis is not always easy. Much easier to do it when there is a typical history of the agricultural workers and acute forms of the disease. Long slow process in humans without proper anamnesis leads to the fact that brucellosis is perceived for cancer, leukemia, and other infectious diseases.
To help to understand the situation, can such tests:
General analysis of blood. Specifies the relative neutropenia due to the increase of the percentage of lymphocytic and monocytic cellular elements of the blood despite normal content of leukocytes. ESR usually moderately accelerated.Long for brucellosis causes of pancytopenia (reduction all blood elements);
Clinical examination of urine. Specific changes determines. There has been a steady increase in protein content in a series of repeated analyses of urine;
Biochemical study of blood. Determines long-lasting slight increase in indicators of hepatic cytolysis (Alt, AST), mild hyperbilirubinemia due to both factions, hyperglobulinemia on the background gipoalbuminemii and normal level of total protein;
For specific verification of the pathogen are used such methods:
Culture. The most accurate, but very laborious and time consuming. For the study, you can take any biological fluid (blood, bile, urine, cerebrospinal and synovial fluid, punctate from lymph nodes). They are sowing on a nutrient medium. The results of the study are evaluated after 3-4 weeks in the presence of growth of colonies typical of Brucella;
Serological. The most widely used method in the diagnosis of brucellosis. Informative from the first week of the disease. The principle of serological diagnosis based on the detection of immunoglobulins (antibodies) in the serum of the patient to the specific Brucella antigens. According to their title and class can be judged on the duration and activity of the process. For this purpose, specific reactions of Wright and Helsana. Diagnostic titer is 1:160-200 and 1:100, respectively;
PCR diagnostics. Modern method and is based on the detection of specific components of DNA-chains of Brucella in the study of any biological tissue of the patient;
Allergic tests. Uses intradermal injection brucellin (component of Brucella). For skin reaction to the injection is judged on the presence sensibilization properties of immune cells against these pathogens. The method does not give information about the activity of the process, but only indicates previous contact with Brucella organism.
Treatment of brucellosis in humans
In connection with the intracellular parasite Brucella in the human body and prolonged course of the disease treatment should also be prolonged. The main components should be causal (pathogen destruction), pathogenetic (impact on mechanisms initiate and sustain the inflammatory process),symptomatic (elimination of anxiety symptoms).
Is performed by the use of antibiotics. It is important to observe some rules:
Simultaneous use of two drugs active against Brucella;
The optimal length for at least 5-6 weeks;
Antibiotics only during exacerbation of the process. The antibiotic in the interictal period will do more harm than good;
The use of high dosages.
Specific therapeutic regimens proved themselves combinations:
Tetracycline with streptomycin;
Rifampicin with doxycycline;
Doxycycline with streptomycin or erythromycin;
Of azithromycin or clarithromycin with Biseptol;
Doxycycline with amikacin.
Represented infusion detoxication measures in the OST process or exacerbation of chronic (glucose-saline solutions, reosorbilakt), vitamins (ascorbic acid, tocopherol, cyanocobalamin, thiamine, pyridoxine, milhama, multivitamin complexes), antihistamines (loratadine, cetirizine, diazolin), immunomodulatory agents (Roncoleukin, tsikloferon, Imunofan in cancer, Echinacea). Glucocorticoids can be used only when strong generalization process and its marked exacerbation.
Symptomatic treatment – the introduction of non-steroidal drugs with anti-inflammatory (diclofenac, newmaximum, Movalis), painkillers, hepatoprotectors, drugs calcium.
Prevention of brucellosis
Preventive measures for brucellosis are nonspecific and presented to combat the spread of pathogens among animals. This can be achieved by early detection, isolation and elimination of the sick animals. Should be careful monitoring of livestock products (milk, meat, wool and skin processing).
Obligatory vaccination of cattle in the epidemic of brucellosis foci on the basis of bruceleroy sample. Only, avoiding the possibility of human contact with Brucella, it is possible to prevent the disease. Vaccination among the people is very rarely, only if the epidemic spread of the disease because it does not provide reliableimmunity and protection.