Brucellosis PDF

# BRUCELLOSIS Brucellosis is caused by the brucella group of organisms. It is gram-negative, aerobic cocco bacilli with 3 serotypes that infect man. * **1-B.abortus** - cattle * **2-B.melitensis** - goats and sheep * **3-B.suis** - pigs Brucella has two antigens: * **A** - B.abortus and B.suis...

# BRUCELLOSIS Brucellosis is caused by the brucella group of organisms. It is gram-negative, aerobic cocco bacilli with 3 serotypes that infect man. * **1-B.abortus** - cattle * **2-B.melitensis** - goats and sheep * **3-B.suis** - pigs Brucella has two antigens: * **A** - B.abortus and B.suis * **M** - B.melitensis ## Transmission Brucellosis is a zoonosis and occupational disease. There are many routes of transmission. * **GIT** * **Direct Contact** * **Respiratory Tract** * **Congenital** * **Human Milk** * **Infected Blood** ## Pathology * Nasopharynx or GIT - regional lymph nodes to RES. Brucella organisms are strictly intracellular, and this explains the chronicity of the disease. Infection is refractory to treatment. * **The infection causes two types of reaction:** * **Hypersensitivity Reaction** - granulomas * **Antibody Reaction to AaM Ags:** * **Primary** - [IgM] response - Widal test * **Secondary** - [IgG] response - Coomb's test * Mononuclear cells distentiona rupture - periodicity ## Presentation There are four ways that brucellosis may present. * **IP** - 2-4 weeks * **1-Symptomless** * **2-Acute** - The onset is rapid or insidious, with non-specific symptoms, drenching sweating (characteristic), headache (almost always present), arthralgia, and arthritis with back tenderness. * **Fever** - Common in acute cases and tends to be stepladder, intermittent, and periodic (each cycle takes 2-4 weeks). * **Splenomegaly** - 27-50% * **Lymphadenopathy** * **2-Chronic cases** - Non-specific symptoms, chronic headache, sweating, backache, mental symptoms, and hepatosplenomegaly are invariably present. ## Complications * **1-Skeletal** - Lumbar region is a predilection, vertebrae and I/V discs may be destroyed leading to sciatica, cauda equina lesion, paraplegia, and sacroilitis. * **2-Brucella Endocarditis** - Serious [AV,MV] * **3-Liver abscesses** * **4-CNS** - Neurobrucellosis - depressiona, suicidal tendency * **5-GU** - Orchitis and pyelonephritis ## Differential Diagnosis * **TB** * **Lymphomas** * **Kala-azar** * **Enteric Fever** - Acute cases ## Causes of Death * **1-Suicide** * **2-Infective endocarditis** * **3-Liver failure** ## Investigations * **General Investigations:** * Normocytic Normochromic Anemia * TWBCs Normal or Reduced * High ESR * LFT - Normal or high * **Specific Investigations:** * **1-Isolation of the organisms from the blood** - Not easy, needs 4-6 weeks to get the result, can be as low as 10% or high as 85%. * **2-BM culture** - 90% * **3-Organisms isolated urine, pus, CSF** - 45% * **4-Liver biopsy** - microgranuloma * **5-Widal test** - IgM used to detect recent disease. * **6-Coomb's test** - IgG Abs in the serum is added to organisms then AHG is added. If positive, it indicates infection, but not it the infection is recent or chronic * **7-ELISA** - Differentiate between IgM, IgG. * **8-PCR** - Detect the presence of brucella antigen. * **9-Brucella skin test** ## Treatment * **1-The standard treatment is STM 1g for 2-3 weeks and doxycycline 100mg BD for 6 weeks** - 6% relapse * **2-Rifampicin 600mg before breakfast for 6 weeks, plus doxycycline 100mgBD for 6 weeks** - 14% relapse * **3-Cotrimaxozole plus Gentamicin** * **In pregnancy, the only safe drug is Rifampicin 600mg daily for 6 weeks.** ## Prevention * **1-Milk should be boiled or pasteurized** * **2-Products of milk should not be made of raw milk** * **3-Animals should be vaccinated**