Brucellosis Types Epidemiology Clinic and treatment

BRUCELLOSIS Types Epidemiology Clinic and treatment


Brucellosis (Bang’s disease, Malta fever, Mediterranean or undulant fever, БРУЦЕЛЛЕЗ, مرض البروسيلا) is a highly contagious zoonotic bacterial disease caused mainly by infection with one of six species of Brucella, a pathogenic gram negative bacteria in the genus Brucella. When an infection is present, signs and symptoms usually appear in early stages, early symptoms include high fever, chills, headache, myalgias (muscle aches), cough, bilateral chest pain, sore throat, tiredness, dyspnea , profuse sweating, dizziness, unsteadiness when walking, hepatosplenomegaly, and lymphadenopathy. In most cases, the disease is transmitted from animals to humans by the ingestion of contaminated products such as unpasteurized milk, cheese and other dairy products. [1]

Brucellosis is characterized by long-lasting flu-like symptoms with hepatosplenomegaly and lymphadenopathy.


  1. Acute brucellosis (up to 3 months)
  2. Subacute brucellosis (up to 6 months)
  3. Chronic brucellosis (over 6 months)
  4. Residual brucellosis

Pathogens – Brucella melitensis, Br. abortus, Brucella suis, Br. canis, Brucella ovis, Br. neotomae.


How do you get brucellosis?

The source of infection:

In most cases, brucellosis is caught from flocks and cattle infected with brucellosis.

How can brucellosis be transmitted to humans?

Mechanism of transmission:

Brucellosis is usually transmitted through the fecal-oral route when humans consume raw milk or cheese from infected goats and sheep. However, brucellosis can also spread through the aerogenic route when people inhale aerosol droplets containing the bacteria or by direct contact with infected animal secretions.

Clinical picture

How long does it take for a person to get brucellosis?

The incubation period for brucellosis ranges from one week to two months.

Acute brucellosis (Острый бруцеллез)

Brucellosis is characterized by an acute onset, symptoms usually develop abruptly and progresses quickly.

What are the signs and symptoms of brucellosis?

Symptoms of brucellosis include:

Intoxication syndrome:

In acute brucellosis, symptoms develop gradually and progress quickly, fever (subfebrile) may also rise, reaching 40 °c in a period of 4 to 6 days. In most patients, fever is characterized by episodes of ups and downs that usually last for 4-6 days, the amplitude of daily fluctuations in temperature ranges between 1.5 – 2.0 degrees, duration of fever up-till 3x months.

Brucellosis is characterized by episodic (periodic) fever

Other symptoms alongside temperature include: malaise, weakness (asthenia), headache, muscle aches (myalgias), cough, bilateral chest pain, dyspnea , anorexia (a loss of interest in food), weight loss, dizziness, unsteadiness when walking, chills, profuse sweating, hepatosplenomegaly, and lymphadenopathy (swollen lymph nodes).  Bacterial-induced lesions in the musculoskeletal system usually cause synovitis (inflammation of the synovial membrane), arthritis (joint inflammation and swelling), and bursitis (inflamed bursae), especially in the shoulder, elbow and hip.

Chills and profuse sweating usually show up in patients while they are still in satisfactory conditions. In most cases, these symptoms usually appear within 2 to 4 weeks after initial infection with brucellosis. A gap between the high temperature and the patient’s overall clinical state (the patient’s satisfactory condition) is characteristic.

Differential diagnosis

The differential diagnosis is carried out with SARS, typhoid fever, psittacosis. Infectious mononucleosis, yersiniosis, pseudotuberculosis, leptospirosis.

Subacute brucellosis (Подострый бруцеллез)

Intoxication syndrome:

In subacute brucellosis, fever becomes paroxysmal in nature, with afebrile periods.

Other symptoms alongside temperature include: increasing weakness, fatigue, irritability, hepatosplenomegaly, and lymphadenopathy (enlarged or swollen lymph nodes).

Without prompt treatment, brucellosis eventually leads to serious complications, such as symptom of musculoskeletal injury (MSI) and physical symptoms of nerve damage (neurological syndrome).

Common symptom of musculoskeletal injury (MSI) include: bursitis, synovitis, fibrositis, pain during movement in the large joints, arthritis

Common symptoms of neurological damage (neurological syndrome) include: radiculitis, plexitis, and meningoencephalitis.

Differential diagnosis

The differential diagnosis is carried out with Q fever, liver abscess, sepsis, systemic connective tissue diseases, Hodgkin’s disease, malaria, and others.

Chronic brucellosis (Хронический бруцеллез)

Chronic brucellosis eventually leads to serious complications, such as symptom of musculoskeletal injury (MSI).

Without prompt treatment, injury of the sacroiliac joints leads to:

  1. Sacroiliitis (inflammation of one or both of your sacroiliac joints), the patient notes pain in the sacroiliac joints when attempting to “move apart” the iliac crest (Kushelevsky symptom)
  2. Ankylosis is an abnormal condition characterized by joint pain and progressive stiffness or immobility due to changes that take place in the joints (fusion of the bones, joint contractures). Ankylosis usually affects large joints (Hip, knee, elbow).

Other symptoms of chronic brucellosis include:

Neurological changes: radiculitis, neuritis, plexites, neuralgia, paresis, nervous disorders, mental disorders.

Urogenital changes: orchitis, orchiepididymitis, adnexitis, endometritis, salpingitis, oophoritis.


Differential diagnosis

The differential diagnosis is carried out with deforming coxarthrosis, rheumatoid arthritis, Reiter’s syndrome, osteo-articular tuberculosis, Ankylosing spondylitis.

Laboratory diagnostics

How to diagnose brucellosis in humans?

Brucellosis is confirmed by testing a sample of blood or bone marrow for the brucella bacteria or by the Brucella microagglutination test (BMAT), that can detect antibodies to Brucella species

Characteristic blood test results of brucellosis include: leucopenia, lymphocytosis, and thrombocytopenia.

Diagnostic imaging testing, such as X-rays are often used to help detect complications of brucellosis, as they can reveal changes in your bones.

Serological diagnosis:

The main Serological methods for diagnosing brucellosis include: Wright’s reaction, RPGA, RSK, Coombs antiglobulin test (using Brucella abortus 99 as antigen to detect incomplete antibodies induced by B abortus RB51 vaccine in cattle), etc.

Characteristic serological test results of brucellosis include:

  1. Wright’s reaction (Wright Heddlsona reaction): a titer of 1:100 or greater confirms the diagnosis, a titer of 80% and higher is usually seen within 1-2 months after the disease onset.
  2. RPGA: a titer of 1:80 or above is usually considered positive for brucellosis
  3. RAC: a titer of 1:40 or greater confirms the diagnosis

Allergic intradermal Burne test – to confirm the diagnosis, an infiltration of 1-3 cm suggests a weakly positive intradermal Burne test, an infiltration of 3-6 cm suggests a positive intradermal Burne test, an infiltration of more than 6 cm suggests a sharply positive intradermal Burne test.


How to treat brucellosis in humans?

Etiotropic therapy

The recommended first line treatment for brucellosis is a combination of rifampicin or streptomycin with either tetracycline, doxycycline, or chloramphenicol for an average of 2 weeks.

Adults with brucellosis are treated with either tetracycline (Sumycin, Achromycin V, Ala-Tet, Tetracap, Tetracon, Brodspec, Panmycin, Robitet) at a dosage of 1.2 – 2.0 g orally twice per day for 14 days, or chloramphenicol (Chloromycetin Sodium Succinate, Chloromycetin) at a dosage of 2,0 – 3,0 g orally twice per day for two weeks, this helps treat any infection caused by Brucella bacteria.

The standard dose of chloramphenicol for adults and teenagers is 5.7 mg per pound of bodyweight every six hours (12.5 mg per kilogram of bodyweight every 6 hrs). The standard dose of chloramphenicol for infants up to 2 weeks of age is 6.25 mg per kg (2.8 mg per pound) of body weight every six hours.

The standard dose of chloramphenicol for infants 2 weeks of age and older is 11.4 mg per pound (25 mg per kg) of body weight every twelve hours, or 5.7 mg per pound (12.5 mg per kg) of body weight every six hours.

The standard dose of tetracycline is 500 mg orally 4 times a day for 3 weeks. Tetracycline is usually given with streptomycin at a dosage of 1 g IM twice a day the first week and once a day thereafter. Women during the last half of pregnancy and children younger than 8 years old should not take tetracycline.

The standard dose of rifampicin is 15 mg per kg of body weight per day in a single morning dose, for at least 45 days. Patients are treated successfully with rifampin administered at a dosage of 600 to 1 200 mg orally every 24 hours, in a single morning dose for 45 days.

The standard dose of doxycycline is 100 mg twice daily for 45 days. Doxycycline is usually given with rifampin at a dosage of 900 mg per day, in a single morning dose for 45 days

Pathogenetic therapy: detoxifying, desensitizing agents, vitamin therapy

In chronic and residual brucellosis – physiotherapy.






  1. [malta fever]

Verified by: Dr.Diab (September 13, 2020)

Citation: Dr.Diab. (September 13, 2020). Brucellosis Types Epidemiology Clinic and treatment. Medcoi Journal of Medicine, 16(2). urn:medcoi:article16294.

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