Infection in the Immunocompromised Flashcards
What immune cells do you need?
Neutrophils - bacterial and fungal
Monocytes- fungal
Eosinophils - parasitic
T lymphocytes - fungal and viral, PJP
B lymphocytes - bacterial
What are supportive factors aimed at reducing risk of sepsis in haematological malignancy?
Prophylaxis - antibiotics, antifungal, antiviral (aciclovir) and PJP (co-trimoxazole)
Growth factors - G-CSF
Stem cell rescue/ transplant
Protective environment - laminar flow rooms
IV immunoglobulin replacement
Vaccination
What can happen post chemo to bone marrow?
Aplasia and neutropenia
What is the neutropenic risk?
Cause of neutropenia - marrow failure higher risk than immune destruction
Degree - significant risk is <0.5x10^9 and high is <0.2
Duration - is more than 7 days then high risk
What are the additional risk factors for infection?
Disrupted skin/ mucosal surfaces - Hickman line, mucositis and GVHD
Altered flora and antibiotic resistance
Lymphopenia - disease process, treatment and stem cell transplantation + GVHD
Monocytopenia
What are the bacterial causes of febrile neutropenia?
Gram-positive bacteria (60-70%)
Gram-negative bacilli
Patterns relate to antibiotics prophylaxis, emerging infection and use of lines
What are the gram positive bacteria seen?
Staph - MSSA, MRSA and coagulase negative
Strep - viridans
Enterococcus faecalis/ faecium
Corynebacterium spp
Bacillus spp
What are some gram-negative bacteria seen?
E.coli
Klebsiella spp - ESBL
Pseudomonas aeruginosa
What are the possible sites of infection?
Resp tract, GI (Typhilitis), dental sepsis, mouth ulcers, skin sored, exit site of central venous catheters and perianal
What is the presentation of neutropenic sepsis?
Fever with no localising signs - single reading above 38.5 or 38 on two readings
Rigors, chest infection, skin sepsis, urinary tract infection and septic shock
What is the definition of severe sepsis/ septic shock?
Signs of systemic inflammation
Presumed infection and organ dysfunction
What is the sepsis 6?
Give high flow O2, blood culture, give IV antibiotics in one hour of presentation, take lactate, IV resuscitation and measure urine output
What are the investigations of neutropenic fever?
History and exam
Blood culture
CXR
Throat swab and other clinical sites
Sputum
FBC, renal and liver function and coagulation screen
What is the management for neutropenic sepsis?
Resuscitation - ABC
Broad spectrum IV antibiotics - tazocin and gentamicin
If gram positive add vancomycin or teicoplanin
If no response at 72hrs add IV antifungal - caspofungin
CT chest/ abdo/ pelvis
What fungal infections can happen in immunocompromised patients?
Candida species and Aspergillus
Life threatening deep seated infection
Lung, liver, sinuses and brain
Monocytopenia and monocyte dysfunction can contribute to risk of fungal infection
What is the therapy for fungal infection?
Empirical - echinocandins - Caspofungin and Anidulafungin
Aspergillus - voriconazole
Moulds - liposomal amphotericin
What are the patients who get infections in severely lymphopenic patients?
Stem cell transplant recipients esp. allogenic
Recipients of total body irradiation
GVHD
Nucleoside analogues or ATG
Lymphoid malignancy - lymphoma, CLL and ALL
What are the infections seen in severely lymphopenic patients?
Pneumonitis - PJP, CMV and RSV
Viral - shingles, mouth ulcers, adenovirus, EBV and SARS-CoV2
Fungal - candida, aspergillus and mucormycotic
Atypical mycobacteria - skin lesions, pulmonary and hepatic involvement
What is the therapy for viral infection?
PJP - high dose co-trimoxazole
CMV - ganciclovir and foscarnet
HSV1 and VZV - aciclovir
Influenza A/B - oseltamivir and zanamivir
Adenovirus - cidofovir
RSV - ribavirin
Immunoglobulin replacement
