Brucellosis: causes, symptoms, diagnosis and treatment

Brucellosis is a zoonotic infection characterized by multiple organ abnormalities and a tendency to chronicity. Important pathogenetic component of brucellosis is allergic reactivity. Transmission of Brucella occurs mainly through food and water, most commonly through milk and meat of infected animals.

The pastoralists can be realized in air and contact transmission of brucellosis. The diagnosis is the detection of the pathogen in the blood, punctate lymph node or cerebrospinal fluid. Serological diagnosis can be considered reliable with a positive result from a number of different methods: ELISA, RLA, Phragmites, RIF, RAC, etc.


Brucellosis is a zoonotic infection characterized by multiple organ abnormalities and a tendency to chronicity. Important pathogenetic component of brucellosis is allergic reactivity. Brucellosis klassificeret on the nature of the flow, distinguishing between acute (lasting up to six weeks), subacute (four months), chronic (more than four months) and residual (long term effects).

Characterization of the pathogen

Brucellosis is called fixed polymorphic gram-positive microorganisms of the genus Brucella. The species of Brucella that cause infection, has an effect on the severity of the most severe is brucellosis due to infection caused by Brucella melitensis. Brucella invasive, they reproduce inside the cells of the host organism, but able to be active and outside the cell. In the environment sustained, preserved in water for more than two months, three months – in raw meat (30 days in saline), for about two months – the cheese and up to four – in the wool of animals. Detrimental for Brucella boiling, heated to 60 °C kills them within 30 minutes.

A reservoir of brucellosis are animals, the source of infection for humans are mostly goats, sheep, cows and pigs. In some cases, possible transmission from horses, camels and some other animals. Abjection happens to sick animals faeces (feces, urine), milk, amniotic fluid. Transmission is mainly fecal-oral mechanism, most often through food and water, in some cases it is possible to implement contact-household (the introduction of the pathogen through microtrauma of the skin and mucous membranes) and aerogenic (inhalation of infected dust).

Significant epidemiological danger are milk obtained from sick animals and milk products (cheese, milk, cheese), meat, products from animal raw materials (wool, leather). Animal feces contaminate soil, water, food that can also contribute to human infection by non-food. Contact-household and air-dust way implemented when caring for animals and processing of animal raw materials.

While brucellosis in pregnant women there is the probability of intrauterine transmission is also possible postnatal transmission during lactation. People have a high susceptibility to brucellosis after the transfer of infections within 6-9 months of retained immunity. Re-infection with Brucella observed in 2-7% of cases.

The clinical picture of brucellosis

The incubation period of brucellosis on average is 1-4 weeks, but the formation of a latent carrier state is extended to 2-3 months. Acute brucellosis usually develops rapidly, older people the onset can be gradual (in this case, patients report prodromal phenomena as a General malaise, insomnia, weakness, arthralgia and myalgia, with a gradual increase in toxicity over several days). The body temperature sharply rises to high numbers, stunning chills alternated with drenching sweat, develops toxicity, most often mild, despite the stated temperature reaction.

The febrile period is usually several days, sometimes puffing up to 3 weeks or a month. Patients report sleep disorders, appetite, headaches, emotional lability. At the peak of the temperature curve marked redness and swelling of the face and neck on the background of blanching. Revealed reasonable polylithionite – lymph nodes, mainly cervical and axillary, somewhat enlarged in size and mildly painful to the touch. In the acute form also may be more characteristic of the subacute course of brucellosis fibrosity and cellulites – tight painful education in the course of the tendons and muscles the size of a pea (sometimes reaching the size of small chicken eggs).

For the subacute form of brucellosis is characterized by the alternation of recurrence of fever with periods of normal temperature. The feverish periods may be of varying lengths, increasing the temperature to vary from subfebrile up to extremely high values (including during the day). Fever is targeted. The increase in temperature is accompanied by intoxication symptoms: pain in muscles and joints, paresthesia (tingling, “pins and needles” in various parts of the body) General weakness, loss of appetite and disturbances of heart rhythm (on the height of fever is relative bradycardia – mismatch rate body temperature). At normal temperature may be increased heart rate. Heart sounds are muffled. Patients feel thirsty, complain of dry mouth, frequent constipation.

This form of the disease is often accompanied by fibrosis and cellulites. In severe may develop infectious-toxic shock, complications such as inflammation of the lining of the heart (pericarditis). Sub-acute form of brucellosis accompanied by allergic manifestations – rashes, dermatitis, vascular reactions, etc.). The first thing usually suffers the articular apparatus: develop reactive arthritis, bursitis and tendovaginitis. For men is characterized by loss of testicles and their appendages, in women, a possible violation of menstruation, endometritis. Brucellosis during pregnancy can contribute to its premature termination.

Chronic brucellosis occurs in waves, with the manifestation of symptoms of multiple organ lesions. While obscheintoksikatsionnogo syndrome (fever and intoxication) is usually expressed moderately, subfebrile temperatures rarely exceed values. The intervals between exacerbations of the disease can last 1-2 months. In the case of the formation of a new infectious focus inside of the body is deterioration of the General condition. Symptoms of chronic brucellosis depends on the pre-emptive destruction of one or another functional system of the causative agent and the severity of the allergic component.

Often develop joint inflammation (arthritis) and surrounding tissues, connective tissue disease (fibrosis, cellulitis) in the lumbar region and sacrum, elbow joints. Sometimes develops spondylitis, significantly worsening the patient’s condition due to the intense pain and limitations in motion. The joints are often subjected to degradation and deformation.

Frequent in patients with brucellosis neuritis (including inflammation of the optic and auditory nerve) and radiculitis, inflammation of the nerve plexus, paresthesia. Long course of the disease contributes to the development of reactive neurosis. In chronic brucellosis is also characterized by allergic inflammation of the sex glands and fertility disorders (infertility in women, impotence in men). Disease duration can be 2-3 years and increase with repeated infection.

Residual brucellosis – the delayed impact of the infection is associated with the formation of pathological reactivity. Due to the restructuring of the immunological structures of the body possible specific response of the body is subfebrile body temperature, psychological deviancy, pathology of joints, connective tissue.

In addition, brucellosis can leave behind serious degenerative changes in the fibrous tissue, especially important in the area of the nerve trunks and plexuses is likely to develop contractures, the occurrence of neurological symptoms (paresis, neuropathy). Long course of the disease contributes to the formation of persistent functional disorders from the musculoskeletal structures due to the irreversible destruction of joint tissues and ligaments (ankylosis and spondylosis, contractures, muscle atrophy). Often such effects of brucellosis are an indication for surgical correction.

Diagnosis of brucellosis

Bacteriological diagnosis is carried out in specialized laboratories equipped for work with pathogens of especially dangerous infections. Brucella isolated from blood, cerebrospinal fluid, puncture of the lymph nodes, producing a bacterial culture test of biological material on a nutrient medium. Due to the significant labor costs abjection rarely produce for diagnostic purposes, sufficient to confirm the diagnosis is the determination of antigens to Brucella in the patient’s blood and serology tests.

The antigens are detected by ELISA, RCA, RLA and RAGA. The research is typically blood serum, but maybe the detection of antigens in cerebrospinal fluid. Detection of antibodies is carried out by the RA, Riha, RAC, RIF, and reactions of Wright and the test for the interaction of Brucella with the serum of the patient. Sufficient for diagnosis is considered a positive result of no less than 3-4 different serological tests. Since 20-25 days of illness and for a long period (several years) after recovery has a positive reaction to a skin test the’byrne (subcutaneous administration brucellin).

Treatment of brucellosis

Outpatient treatment is indicated in severe infections. In the case of heavy currents and the threat of complications produce the hospitalization. For the period of the fever patients is shown to bed. Causal treatment involves antibiotics of different groups, one of the drugs must possess the ability to penetrate through the cell wall. Effective use antibiotikov the following pairs: rifampicin with doxycycline or ofloxacin, doxycycline with streptomycin. In the case of recurrence, re-assign a course of antibiotics.

In addition to the basic therapy of prescribe pathogenetic and symptomatic agents: detoxification therapy (depending on severity of intoxication), an immunostimulating drug (extract of the thymus of cattle, pentoxy), procaine blockade in the intensive spondylitis and sciatica, anti-inflammatory drugs (non-steroidal drugs and corticosteroids, depending on the currents and articular manifestations).

Earlier in the treatment of brucellosis used therapeutic vaccine, but at present refuse from this practice due to the marked suppression of the immune system and the ability of a vaccine to induce autoimmune processes. During remissions, patients are recommended SANATORNO-resort treatment, effects of physiotherapy (UHF, quartz, radon baths, etc.) and therapeutic exercises.

Forecast and prevention of brucellosis

Brucellosis usually does not cause death of patients, the prognosis is usually favorable. In cases of prolonged course and the development of persistent, destructive articular defects of the device may limit ability to work.

In the complex of preventive measures aimed at reducing the incidence of brucellosis in people included veterinary monitoring the condition of farm animals, as well as sanitary-hygienic regulation of the conditions of production, storage and transportation of food products, annual preventive examinations of workers of agriculture.

Agricultural cattle subject to routine vaccination, the specific prevention with vaccination of live Brucella vaccine shown to persons working directly with the animals. To the means of individual prevention also applies the uniform for working with the animal raw materials, strict observance of rules of personal hygiene.

2 thoughts on “Brucellosis: causes, symptoms, diagnosis and treatment

  1. Transmission is mainly fecal-oral mechanism, most often through food and water, in some cases it is possible to implement contact-household (the introduction of the pathogen through microtrauma of the skin and mucous membranes) and aerogenic (inhalation of infected dust).

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