Diagnosis of brucellosis

Step 1: History taking

The first step in evaluation is gathering diagnostically significant information from the patient's complaints and history (Anamnesis morbi).

In the acute course, patients report prolonged fever (which is often tolerated quite well), severe chills, profuse sweats, general malaise, insomnia, and multiple muscle and joint pains (polyalgesia). If the process is subacute or chronic, relapses of fever, irritability, decreased performance, and localized pain (in the lumbosacral spine, along nerve trunks) come to the forefront.

Special attention is paid to the epidemiological history. The physician must determine:

• Whether there was contact with farm livestock or raw animal products.
• Whether the patient consumed raw milk or homemade dairy products.
• Whether they reside in an endemic area.
• Whether there is occupational risk (e.g., working in a laboratory with live Brucella cultures).

Step 2: Physical examination

Upon examination, symptoms clearly correlate with the form of infection. Acute brucellosis is characterized by:

• High fever (intermittent, remittent, or irregular).
• Hepatosplenomegaly (enlargement of the liver and spleen).
• Systemic lymph node enlargement (polyadenopathy).
• Possible skin rashes.

Subacute and chronic forms manifest as deep focal lesions of organs and systems:

• Musculoskeletal system: arthritis, sacroiliitis, spondylitis, osteoperiostitis, as well as fibrositis and cellulitis.
• Nervous system: neuralgia, neuritis, radiculitis, meningoencephalitis, and development of "psychoneurosis".
• Urogenital tract: in men, orchitis and epididymitis develop; in women, oophoritis, endometritis, salpingitis, and dysmenorrhea up to spontaneous miscarriage.

Step 3: Laboratory confirmation

Definitive diagnosis is impossible without a complex of laboratory and immunological tests.

1. Complete blood count: typical decrease in leukocyte and platelet counts, relative increase in the proportion of lymphocytes and monocytes against the background of an unchanged erythrocyte sedimentation rate (ESR).
2. Serological methods: detection of specific antibodies in diagnostic titers using Wright's, Huddleson-Kaitmazov, complement fixation test (CFT), indirect hemagglutination assay (IHA), as well as Coombs and immunofluorescence (IFA) tests.
3. Immunological methods: detection of pathogen antigens via ELISA, co-agglutination assay, latex agglutination assay.
4. Allergy diagnostics: performing the Burnet intradermal test, a positive result of which indicates organism sensitization.

Step 4: Clinical diagnosis formulation

A detailed clinical diagnosis is formulated according to a clear algorithm that takes into account all aspects of the patient's condition.

First, the form of the disease (acute, subacute, chronic, or residual) and its severity (mild, moderate, severe) are determined. Then, in a prolonged course, the phase is indicated (with or without relapsing generalization).

The most important criterion for disability assessment is the state of compensation:

• Compensation: symptoms are present, but working capacity is preserved.
• Subcompensation: partial loss of working capacity.
• Decompensation: complete disability of the patient.

At the end of the diagnosis, the leading lesion must be specified (e.g., nervous or osteoarticular form). Example of a correct entry: "Subacute brucellosis without relapsing generalization, osteoarticular form, moderate course, state of compensation".

Management tactics and follow-up (dispensary care)

After establishing the diagnosis, an individual treatment plan is developed. Etiotropic therapy requires the simultaneous prescription of two antibacterial drugs (e.g., rifampicin and doxycycline) as a prolonged continuous course for at least six weeks. In subacute and chronic courses, the focus shifts to pathogenetic agents (NSAIDs, glucocorticosteroids for severe nervous system lesions) and non-specific stimulating therapy.

Discharge of the patient is allowed only upon complete recovery or sustained improvement. Subsequently, convalescents are placed under strict dispensary follow-up for 2 years with a comprehensive examination every 5–6 months. If clinical signs are absent during this period and serological reactions steadily fade, monitoring is terminated. Contact persons are assigned mandatory follow-up at 3 months, and in case of high threat, emergency drug prophylaxis is carried out.

Class and exam questions

What else to study on this topic

• Principles and regimens of combination antibiotic therapy
• Features of pathogenetic treatment: use of NSAIDs and GCS
• Specific prophylaxis: vaccination in endemic regions
• Emergency chemoprophylaxis under threat of infection
• Veterinary and sanitary measures for morbidity control

Other topics in the section "Zoonotic infections — 2024 study guide"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.