1. 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

2. Infections In The Immunocompromised Host
The importance of infections in IC host:
Increasing numbers of immunocompromised patients.
Seriousness of infections in these patients.
Infections with unusual microorganisms.
Atypical presentation of infections by common pathogens

3. Infections In The Immunocompromised Host
Causes of immune deficiency:
Primary (congenital);
Rare; more common in children:
chronic granulomatous disease, combined immunodeficiency syndrome, specific Ig deficiency, others.
Secondary (acquired);
Common; 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.

4. Infections In The Immunocompromised Host: Host Defects and Associated Prevalent Pathogens
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
Neisseria meningitides.
Spleen dysfunction
Neisseria meningitides, Neisseria gonorrhea
Complement deficiency

5. Fever In Neutropenic Patient
Definition:
Fever: Oral temperature of 38 C for more than two hours or single temperature of C or greater.
Neutropenia: A Neutrophil count of <500 cells/mm³ or a count of <1000 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 CID;2002:34:

6. Fever in the Neutropenic Patient SEQUENTIAL INFECTIVE EVENTS

7. Fever In Neutropenic Patient: Etiology

8. Fever In Neutropenic Patient
IDSA guidelines CID;2002:34:

9. IDSA guidelines CID;2002:34:730-751

10. IDSA guidelines CID;2002:34:730-751

11. IDSA guidelines CID;2002:34:730-751

12. IDSA guidelines CID;2002:34:730-751

13. IDSA guidelines CID;2002:34:730-751

14. Treatment of Fever in the Neutropenic Patient
Antibacterials:
Piperacilline-tazobactam + aminoglycoside or
Cefepime + aminoglycoside or
Imipenem
Vancomycin, if indicated.
Antifungals:
Amphotericin, Fluconazole
Antiviral:
Acyclovir
Patient must receive Granulocyte stimulating factors concomitantly.

15. 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

16. CMR;1997:

17. 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 anti-rejection therapy.
The occurrence of surgical complications.
Presence of latent infection in the donor or recipient.
CID;2001 (supp 1):S5-S8

18. Infections in Organ Transplant Recipients
TB, Legionella
Histoplasma, Nocardia, Toxoplasma, Pneumocystis
Candida, Aspergillosis
EBV, CMV, HBV
VZV, CMV
Common bacteria 1 2 3 4 5 6 7 8 9 10
Months post transplantation
CID;2001 (supp 1):S5-S8