Infection

Question 1

What immune cells are associated with which infections

Answer 1

Neutrophils- bacterial and fungal infection
Monocytes- fungal infection
Eosinophils- parasitic infection
T lymphocytes- fungal and viral infection, PJP
B lymphocytes- bacterial infection

Question 2

Supportive measures aimed at reducing risk of sepsis in haematological malignancy

Answer 2

Prophylaxis

• antibiotics,
• antifungals
• antiviral
• PJP (co-trimoxazole)

Growth factors eg G-CSF

Stem cell rescue/ transplant

Protective environment- laminar flow rooms

IV immunoglobulin replacement

Vaccination

Question 3

Cause of neutropenia
Degree of neutropenia
Duration of neutropenia

Answer 3

Cause- marrow failure, immune destruction

Degree- <0.5 x10(9)/l signif risk
<0.2x10(9)/l high risk

Duration- >7 days = high risk

Question 4

Other risk factors for infection

Answer 4

Disrupted skin, 
Mucosal surfaces 
Altered flora,
Antibiotic resistance,
Lymphopenia, 
Monocytopenia

Question 5

Febrile neutropenia bacterial causes

Answer 5

Gram positive bacteria

Gram negative bacilli

Question 6

Gram positive bacteria

Answer 6

Staph: MSSA, MRSA, coagulase negative 
Strep: viridans, 
Enterococcus faecalis/ faecium
Corynebacterium spp
Bacillus spp

Question 7

Gram negative bacteria

Answer 7

E.coli
Klebsiella
Pseudomonas aeruginosa
Enterobacter spp
Acinetobacter spp
Citrobacter spp
Stenotrophomonas maltohilia

Question 8

Possible sites of infection

Answer 8

Respiratory tract
Gastrointestinal
Dental sepsis 
Mouth ulcers 
Skin sores 
Exit site of central venous catheters  
Perianal

Question 9

Common fungal infection in immunocompromised patients

Answer 9

Candida species,
Aspergillus

*monocytopenia and monocytes dysfunction contribute to risk of fungal infection

Question 10

Presentation of neutropenia sepsis

Answer 10

Fever with no localising signs
Single reading of >38.50C or 380C on two readings one hour apart
Rigors
Chest infection/ pneumonia
Skin sepsis - cellulitis
Urinary tract infection
Septic shock

Question 11

Definition of severe sepsis/ septic shock

Answer 11

Signs of systemic inflammation
+
Presumed infection and organ dysfunction

Question 12

sepsis 6 treatment

Answer 12

Administer high flow oxygen

Take blood cultures, other cultures, consider source control

Give appropriate IV antibiotics within ONE hour

Measure serum lactate concentration

Start IV fluid resuscitation

Assess/measure urine output

Question 13

Investigation of neutropenic fever

Answer 13

History and examination
Blood cultures-Hickman line & peripheral
CXR
Throat swab & other clinical sites of infection
Sputum if productive
FBC, renal and liver function, coagulation screen

Question 14

Management of neutropenic sepsis

Answer 14

Resuscitation – ABC

Broad spectrum I.V. antibiotics
- Tazocin and Gentamicin

If a gram positive organism
-add vancomycin or teicoplanin

No response at 72 hours
-add I.V. antifungal treatment e.g. Caspofungin

CT chest/abdo/pelvis to look for source

Modify treatment based on culture results

Question 15

Example of infection in severely lymphopenic patients

Answer 15

Stem cell transplant recipients, especially allogeneic
Recipients of Total Body Irradiation (TBI)
Graft vs Host Disease
Nucleoside analogues (fludarabine) or ATG
Lymphoid malignancy e.g Lymphoma, CLL, ALL

Atypical pneumonia:

• PJP
• CMV
• RSV

Viral:

• shingles (varicella zoster)
• mouth ulcers (herpes simplex)
• adenovirus
• EBV (PTLD)

Fungal:
-candida, aspergillus, mucormycosis

Atypical mycobacteria
-skin lesions, pulmonary and hepatic involvement