Infections in Immunocompormised Patients

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Infections in Immunocompormised Patients
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Factors Compromising Immunity

• Neutropenia
• Impaired cell mediated immunity
• Humoral immune dysfunction
• Splenectomy
• Damage to mucosal surfaces
• Breaks of anatomical barriers
• Local factors

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Neutropenia

• Often due to myelosuppression by antineoplastic
  therapy
• Infection depends on degree and duration of
  neutropenia
• Neutrophil lt 500/mm3 High risk of infections
• Neutrophil lt 100/mm3 High risk of life
  threatening infection
• Most patients fail to develop characteristic
  signs of infection.
• Only 30 of febrile patients have ve blood
  cultures.
• Commonest source of pathogens is GIT.
• Fungal infections occur late in prolonged
  neutropenia.
• Consider other causes of fever.

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Infections in Neutropenic Patients

• Common sites of Infections
• Oropharynx, lung, paranasal sinuses, skin soft
  tissues, perianal area, urinary tract.
• Infections are often caused by organisms
  colonising the patient

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Infections in Neutropenic Patients

• Bacterial infections
• Gram ve bacteria are the most common .
• Gram ve cocci increased recently.
• Anaerobes are uncommon.

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Infections in Neutropenic Patients
Fungal infections

• Frequent in patients with prolonged neutropenia
• Candida sp.
• Superficial infections
• Candidemia invasive candidiasis
• Invasive aspergillosis (pneumonia)
• Other fungi mucormycosis, pseudoallescheria,
  fusarium

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Infections in Neutropenic Patients
Viral infections

• Herpes simplex
• Herpes zoster
• Cytomegalovirus

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Infections in Neutropenic Patients
Patient Evaluation

• Initial clinical evaluation
• Septic workup
• Laboratory tests
• Radiological imaging
• Invasive procedures

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Infections in Neutropenic Patients
Emperical Therapy

• Rationale
• Febrile neutropenic patients
• 50 have clinical or microbiological evidence of
  focus or cause of infection
• 50 have unexplained fever
• 35 respond to emperical therapy
• 15 donot respond

Further diagnostic therapeutic
procedures
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Infections in Neutropenic Patients
Empirical Therapy

• Initial regimen to cover gram ve baccilli
• Broadspectrum b lactum Aminoglycosids
• Carbapenem
• B-lactam allergy quinolone / aztreonam
• Add vancomycin if evidence of Gramve infection
  or failure to respond
• Add Amphorencin B if fail to repond after 5
  days of therapy.

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Infections in Neutropenic Patients
Empirical therapeutic regimens

• No significant difference in efficacy of regimens
• Regimen should cover locally prevalent pathogens
• Most patient respond within 4-5 days
• Failure to respond after 5 days modify therapy

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Infections in Neutropenic Patients
Empirical therapy

• Remove central venous catheter if persistent
  bactromia / fungemia
• Response depends on recovery of neutropenia
• D/C all therapy after 5 afebrile days
• No need to continue amphotrecin if no evidence of
  invasive mycosis
• Specific therapy for documented infections

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