Infections%20In%20The%20Immunocompromised%20Host

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Infections In The Immunocompromised Host

• Objectives of this lecture
• To review the components of the host defense
  mechanisms
• To recognize the importance of immunodeficiency
  and infections
• To know the common infectious complications in
  major immunodeficiency categories(other than
  HIVAIDS)

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Infections In The Immunocompromised Host

• Components of Host Defenses
• Mechanical barriers
• Skin, mucous membranes,
  epiglottis, cilia.
• Granulocytes
• Cell mediated Immunity
• Macrophages, T-lymphocytes,
  NKC, cytokines
• Humoral Immunity
• B-lymphocytes, immunoglobulins,
  complements
• Spleen
• Davidson's Principles and Practice of
  Medicine 20th edition chapter 4 pages 64-75

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Infections In The Immunocompromized Host

• The importance of infections in IC host
• Increasing numbers of Immunocompromised
  patients.
• Seriousness of infections in those patients.
• Infections with unusual, nonpathogenic
  microorganisms.
• Atypical presentation of infections by common
  pathogens

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Infections In The Immunocompromized Host

• Causes of immune deficiency
• Primary (congenital)
• Rare, more common in children e.g
  chronic granulomatus disease, combined
  immunedifiency syndrome, specific Ig deficiency,
  others.
• Secondary (acquired)
• The commonest, there are many
  causes like
• Extremes of age, pregnancy,
  infections, malignancy, chemotherapy, steroids,
  burns, trauma, procedures, connective tissue
  diseases, chronic diseases like DM,CRF etc.
• Davidson's Principles and Practice of Medicine
  20th edition chapter 4 pages 64-75

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Infections In The Immunocompromized HostHost
Defects and Associated Prevalent Pathogens
Pathogen Defect
Staph. Aureus,CNSS, V strep, Enterococci, E. coli, Pseudomonas aeruginosa, K.pneumoniae, other gram ve bacilli, Aspergillus spp Granulocytopenia
CNSS, Staph. Aureus, pseudomonas aeruginosa and other gram-ve bacilli, candida spp, V. strep, enterococci, HSV. Damaged skin and mucous membrane
HSV, VZ, EBV, CMV, RSV, M. tuberculosis, Aspergillus spp and other fungi, Toxoplasma gondi. Impaired CMI
Streptococcus pneumoniae, Haemophilus influenzae Impaired humoral immunity
Streptococcus pneumoniae, Haemophilus influenzae Neisseria meningitides. Spleen dysfunction
Neisseria meningitides, Neisseria gonorrhea Complement deficiency
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Fever In Neutropenic Patient

• Definition
• Fever Oral temperature of 38c for more than
  two hours or single temperature of 38.3c or
  more.
• Neutropenia A Neutrophil count of lt500
  cells/mm³ or a count of lt1000 cells/mm³ with a
  predicted decline to 500/mm
• Approach to patient
• Careful history and examination,
  investigations (like blood cultures, urine
  culture, CXR, others), then start antibiotic
  therapy to cover the most likely organisms.

IDSA guidelines CID200234730-751
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Fever In Neutropenic PatientSEQUENTIAL INFECTIVE
EVENTS
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Fever In Neutropenic Patient

• Causes of fever in neutropenic patients

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Fever In Neutropenic Patient
IDSA guidelines CID200234730-751
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IDSA guidelines CID200234730-751
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IDSA guidelines CID200234730-751
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IDSA guidelines CID200234730-751
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IDSA guidelines CID200234730-751
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IDSA guidelines CID200234730-751
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Fever In Neutropenic Patient

• Treatment
• Antibacterial like
• pipracilline aminoglycoside or ceftazidime
  aminoglycoside or Imipenem, vancomycine.
• Antifungal like
• Amphotericine B, Fluconazole
• Antiviral like
• Acyclovir
• Granulocyte stimulating factors

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Infections in Solid-Organ Transplant Recipients

• Factors affecting the incidence of infections
• The type of organ transplanted.
• The degree of immunosupression.
• The need for additional antirejection
  therapy.
• The occurrence of surgical complications.
• Presence of latent infection in the donor
  or recipient.

CID2001 (supp 1)S5-S8
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Infections in Organ Transplant Recipients

• Common infection in Specific Organ transplant
• Bone marrow transplant Bloodstream
  infections, pneumonia, viral infections
• Kidney transplant
  Urinary tract infections.
• Liver transplant
  Intra abdominal infections.
• Heart and Heart-Lung Chest,
  Mediastinitis
• transplant

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CMR1997277-297
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Infections in Organ Transplant Recipients
TB,Legionella
Histoplasma,Nocardia,Toxoplazma,Pneomocystis
Candida,Aspergillosis
EBV,CMV,HBV
VZV,CMV retinitis
Common bacteria
1
2
3
4
8
9
5
6
7
10
Months post transplantation
CID2001 (supp 1)S5-S8
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INFECTIONS IN IMMUNOCOMPROMISED HOST

• Suggested readings
• Davidson's principles and practice of
  medicine 20th edition
• Harrison's Principles of Internal Medicine
  16th or 17th edition