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Brucellosis

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Brucellosis Powered By Docstoc
					By Dr.Sujith
Brucellosis is a zoonotic infection transmitted to
 humans
contact with fluids from infected animals (sheep,
 cattle, goats, pigs, or other animals)
derived food products such as unpasteurized milk
 and cheese .
The disease is rarely, if ever, transmitted between
 humans.
Other names
Undulant fever
Malta fever
Gibraltar fever
Mediterranean fever.
 Brucella spp are small gram-negative aerobic
  coccobacilli lacking a capsule, flagella, endospores,
  or native plasmids.
 Oxidase and catalase tests are positive for most
  members of the genus Brucella.
 Some species require CO2 enrichment for primary
  isolation in the laboratory.
 Other methods for the identification and
  speciation of Brucella include:
production of urease and H2S
sensitivity to dyes, basic fuchsin, thionin, and
 thionin blue
use of specific antisera
Epidemiology
 Brucellosis occurs worldwide; major endemic
 areas include countries of the Mediterranean
 basin, Arabian Gulf, the Indian subcontinent, and
 parts of Mexico, Central and South America
Human Infection:B. melitensis is the species that
 infects humans most frequently.
The incubation period ranges from a few days to a
 few months.
The disease is manifested as fever accompanied by
 a wide array of other symptoms.
Methods of transmission
 Direct inoculation through cuts and skin abrasions
  from handling animal carcasses, placentas, or
  contact with animal vaginal secretions
 Direct conjunctival inoculation
 Inhalation of infectious aerosols
 Ingestion of contaminated food such as raw milk,
  cheese made from unpasteurized (raw) milk, or
  raw meat
 Venereal transmission has been suggested, but the
  data are not conclusive
Incubation Period
 1 week to several months
Clinical Manifestation
 Fever
 Night sweats
 Malaise
 Anorexia
 Arthralgia
 Fatigue
 Weight loss
 Depression.
 Patients may have a multitude of complaints
  without objective findings except fever.
 Often fits one of the three pattern:
febrile illness resembling typhoid,less severe
fever & acute monoarthritis (hip/knee),young child
long lasting fever,LBA,hip pain,older man

 Travel to an endemic area
 Occupation
 Consumption of unpasteurized milk
Physical Examination
 Physical manifestations may be absent.
 If present,
Focal Features:
Musculoskeletal pain
Osteomyelitis
Septic Arthritis
Minimal lymphadenopathy
Hepatosplenomegaly ocacsionally.
 Osteoarticular disease, especially sacroileitis — 20
  to 30 percent and vertebral spondylitis. Large
  joints are affected most commonly in children
 Genitourinary disease, especially epididymo-
  orchitis — 2 to 40 percent of males
 Neurobrucellosis, usually presenting as meningitis
  — 1 to 2 percent.
 Less common neurologic complications include
 papilledema, optic neuropathy, radiculopathy,
 stroke, and intracerebral hemorrhage
 Endocarditis — 1 percent.Most cases of
  endocarditis are left-sided, and about two-thirds
  occur on previously damaged valves.
 Hepatic abscess — 1 percent
 Other less common complications include
  pneumonitis, pleural effusion, empyema,, or
  abscess involving the spleen, thyroid, or epidural
  space, uveitis.
 A few cases of Brucella infection involving
  prosthetic devices such as pacemaker wires and
  prosthetic joints have been reported
Differentials
 Tuberculosis
 Toxoplasmosis
 CMV
 HIV infection
 Patients with undiagnosed and untreated
  brucellosis can be symptomatic for months. In
  addition, previously treated patients may present
  with relapsed infection.
 The presence of granulomatous hepatitis, hepatic
  microabscesses, bone marrow granulomas, and/or
  hemophagocytosis should prompt further
  diagnostic evaluation for brucellosis.
 Relapse — About 10 percent of patients relapse
  after therapy
Relapse
 About 10 percent of patients relapse after therapy.
 Most relapses occur within three months following
  therapy and almost all occur within six months.
 Risk factors for relapse include inadequate initial
 therapy, duration of the initial illness of less than
 10 days, male sex, bacteremia, and
 thrombocytopenia
Laboratory
 Total counts-Normal/reduced
 Thrombocytopenia
 ESR/CRP-Normal/Increased
 CSF/Body fluid analysis-Lymphocytosis,low glucoce
  levels,elevated ADA
 Biopsied samples of lymph node,liver-non caseating
  granuloma without acid fast bacilli.
Cultures
 Polymerase chain reaction (PCR) shows promise
  for rapid diagnosis of Brucella spp in human blood
  specimens
 Positive PCR at the completion of treatment is not
  predictive of subsequent relapse
 PCR testing for fluid and tissue samples other than
  blood has also been described
Serological Tests
 Most serological studies for diagnosis of
  Brucellosis are based on antibody detection
These include:
 Serum agglutination (standard tube agglutination)
 ELISA Rose Bengal agglutination
 Complement fixation
 Indirect Coombs
 Immunecapture-agglutination (Brucellacapt
Serum agglutination
 It is generally agreed that a titer of >1:160 in the
  presence of a compatible illness supports the
  diagnosis of brucellosis.
 Demonstration of a fourfold or greater increase or
 decrease in agglutinating antibodies over 4 to 12
 weeks provides even stronger evidence for the
 diagnosis.
ELISA
 ELISA is probably the second most common
  serologic method.
 The sensitivity of the ELISA was 100 percent when
  compared with blood culture but only 44 percent
  compared with serologic tests other than ELISA
 The Specificity was >99 percent.
 In a study including 75 patients with brucellosis,
  five patients with positive ELISA had a negative
 tube agglutination test
Synovial fluid
 In the setting of Brucella arthritis, the synovial
  fluid white blood cell count does not generally
  exceed 15,000 cells/microL.
 In brucellosis, lymphocytes frequently
  predominate (in contrast to septic arthritis due to
  other bacteria, in which polymorphonuclear
  leukocytes frequently predominate.
Imaging
 Patients with spine symptoms MRI examination
  to rule out spinal cord compromise.



 Plain radiographs, radionuclide bone scintigraphy,
  CT scanning, and joint sonography.
Radiology of Spine
                        Brucellosis            Tuberculosis
Site                    Lumbar                 Dorso lumbar
Vertebrae               Multiple,contigous     Contigous
Diskitis                Late                   Early
Body                    Intact until late      Morphology lost early
Canal compression       Rare                   common
Osteophyte              Anterolateral          unusual
Deformity               Wedging uncommon       Anterior wedging
Recovery                Sclerosis              Variable
Paravertebral abscess   Small well localized   Common,discrete
                                               loss,transverse process
Psoas Abscess           Rare                   More likely
 Localized snowflake calcification in chronic
  hepatosplenic brucellosis only specific
  radiographic finding.
Treatment
 Antibiotic Therapy
There are two major regimens:
Regimen A: Doxycycline 100 mg orally twice daily for
 6 weeks + Streptomycin 1 gram intramuscularly
 once daily for the first 14 to 21 days
 Regimen B: Doxycycline 100 mg orally twice daily
  plus rifampin 600 to 900 mg (15 mg/kg) orally
  once daily for six weeks.
Focal Disease
 Patients with focal disease have a less favorable
  prognosis. In a study of 530 patients (including
  170 patients with focal disease); those with focal
  disease had a greater likelihood of therapeutic
 failure, relapse, or death.
Indications for Surgery
 Endocarditis where valve replacement or valve
  debridement is required
 Drainage or excision of abscesses, especially those
  that have not responded to antimicrobials
 Spinal epidural abscess
 Removal of infected foreign bodies, eg, pacemaker
  wires, prosthetic joints
 Resection of mycotic aneurysms
 Procurement of tissue for diagnostic purposes
 Chronic hepatosplenic suppurative brucellosis
  may require surgery in addition to antibiotics to
 achieve cure
Osteoarticular Disease
 Patients with Brucella spondylitis appear to
  respond better to doxycycline-streptomycin or a
  three-drug regimen (doxycycline-streptomycin-
  rifampin) than to doxycycline-rifampin.
Neurobrucellosis
 Doxycycline,
 Rifampin
 Trimethoprim-sulfamethoxazole .
 The duration of therapy is generally prolonged
  individualized according to clinical signs and
  symptoms
 Continued until cerebrospinal fluid parameters
 have returned to normal
Endocarditis
 Antimicrobial therapy alone may be attempted
  absence of heart failure, valvular destruction,
  abscess, or a prosthetic valve.



 A combination of three or four antimicrobials, eg,
  a tetracycline, rifampin, and an aminoglycoside
  plus or minus trimethoprim-sulfamethoxazole.
 Therapy is usually given for six weeks to six
  months.



 The aminoglycoside component is usually
  administered for two to four weeks in an effort to
  avoid toxicity
Relapse
 Relapse should prompt assessment for a focal
  lesion, especially hepatosplenic abscess

 Most relapses can be treated successfully with a
 repeat course of a standard regimen.

 Should resistance or a second or third relapse
 occur, an alternative regimen should be devised.
Pregnancy
 Premature labor and fetal wastage


 Rifampin — 900 mg once daily for six weeks


 Rifampin — 900 mg once daily plus trimethoprim-
  sulfamethoxazole(TMP-SMX; 5 mg/kg of the
  trimethoprim component twice daily) for four
 weeks
Thank you

				
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