BRUCELLOSIS Flashcards
Organism
Brucella are aerobic, non-spore-forming, non-motile, gram-negative coccobacilli
Etiology
🌚Brucellosis is an important zoonotic disease that result either from direct contact with an infected animal or by consumption of their meat or products (especially unpasteurized milk products),
😡 it also may occur by inoculation through cuts or conjunctiva, or by inhalation of infectious aerosols.
Pathology
😁The major virulence factor for Brucella appears to be the smooth lipopolysaccharide (LPS) of its cell wall which makes it more resistant to killing by PMN
😃 because these organisms are facultative intracellular pathogens, they can survive and replicate within the mononuclear phagocytic cells of the RES resulting in granuloma formation.
Clinical menifestation
😰 The incubation period is 2-4 wk.
😆Hx. Symptoms are usually non-specific & vague e.g. fever, night sweats, anorexia, headache, fatigue, arthralgia, rash, abdominal pain, diarrhea, vomiting, cough, and pharyngitis.
😆Some patients may present with only FUO
😆but the most consistent part of hx is the direct contact with an infected animal or by consumption of their meat or products.
🧐🧐Ex. Pyrexia, pallor, skin rash, arthritis (especially spine), LAP, & hepatosplenomegaly.
Investigations
CBP; Pancytopenia, i.e. anemia, neutropenia, & thrombocytopenia.
Culture of blood or any tissue of the RES (e.g. liver, spleen, lymph nodes, or BM) is the gold standard in Dx,
Serology; Serum Agglutination Test (SAT) or Brucella Agglutination Test (BAT)
ELISA is more sensitive but less specific than SAT.
PCR is very sensitive & specific.
TX
Children < 8 yr are usually treated with TMP (10 mg/kg)- SMZ (50 mg/kg) + Rifampin (15-20 mg/kg).
Children > 8 yr are usually treated with Doxycycline (2-4 mg/kg) + Rifampin [or Streptomycin (20-30 mg/kg) or Gentamicin (3-5 mg/kg)].
All drugs should be given for 6 wk except Aminoglycosides for 2 wk.
Patients with Cxs e.g. osteomyelitis, endocarditis, or meningitis should be treated with Doxycycline + Gentamicin +/_ Rifampin for 4-6 mo (except gentamicin for 1-2 wk).
Note: Patients should be complaint with this prolong therapy to reduce the relapse rate.