Transcript Infections In The Immunocompromized Host

Infections In The
Immunocompromized 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
Infections In The
Immunocompromized Host
The importance of infections in IC host:
Increasing numbers of immunocompromized patients.
Seriousness of infections in those patients.
Infections with unusual, nonpathogenic microorganisms.
Atypical presentation of infections by common pathogens
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.
Infections In The
Immunocompromized Host
Host Defects and Associated Prevalent Pathogens
Defect
Pathogen
Granulocytopenia
Staph. Aureus,CNSS, V strep, Enterococci, E. coli, Pseudomonas
aeruginosa, K.pneumoniae, other gram –ve bacilli, Aspergillus spp
Damaged skin and
mucous membrane
CNSS, Staph. Aureus, pseudomonas aeruginosa and other
gram-ve bacilli, candida spp, V. strep, enterococci, HSV.
Impaired CMI
HSV, VZ, EBV, CMV, RSV, M. tuberculosis, Aspergillus spp
and other fungi, Toxoplasma gondi.
Impaired humoral
immunity
Streptococcus pneumoniae, Haemophilus influenzae
Spleen dysfunction
Streptococcus pneumoniae, Haemophilus influenzae
Neisseria meningitides.
Complement
deficiency
Neisseria meningitides, Neisseria gonorrhea
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 <500 cells/mm³ or a count
of <1000 cells/mm³ with a predicted decline to 500/mm
IDSA guidelines CID;2002:34:730-751
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.
Fever In Neutropenic Patient
SEQUENTIAL INFECTIVE EVENTS
Fever In Neutropenic Patient
Causes of fever in neutropenic patients;
Fever In Neutropenic Patient
IDSA guidelines CID;2002:34:730-751
IDSA guidelines CID;2002:34:730-751
IDSA guidelines CID;2002:34:730-751
IDSA guidelines CID;2002:34:730-751
IDSA guidelines CID;2002:34:730-751
IDSA guidelines CID;2002:34:730-751
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
Infections in Organ Transplant
Recipients
Common infection in Specific Organ transplant:
Bone marrow transplant
Kidney transplant
Bloodstream infections, pneumonia,
viral infections
Urinary tract infections.
Liver transplant
Intraabdominal infections.
Heart and Heart-Lung
transplant
Chest, Mediastinitis
CMR;1997:277-297
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.
CID;2001 (supp 1):S5-S8
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
5
6
7
8
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10
Months post transplantation
CID;2001 (supp 1):S5-S8