CA - Bloodstream infections - Bacteraemia, line infections, endocarditis (CKL) Wk 4

Question 1

Whats serology & why do we need to do serology?

Answer 1

• To detect antibodies in the blood
• mostly for detecting viruses & some bacteria that cant be cultured or parasites
• but antibody take time to develop

Question 2

Whats the difference between bacteraemia & septicaemia?

Answer 2

Bacteraemia
- Presence of bacteria in blood
- might not exhibit signs of infection

Septicaemia = Presence of bacteria in blood with outward signs of infection
- can lead to sepsis if not treated

Question 3

What is SIRS used for? What are signs of SIRS (systemic inflammatory response syndrome)? (4)

Answer 3

• objective indicators of sepsis

1. Heart rate >90/min
2. Respiratory rate >20/min
3. Pyrexia: raised body temp >38 or hypothermia: lowered body temp <36
4. Raised WBC > 12000 or leukopenia WBC < 4000

Question 4

How does bacteraemia occur?

Answer 4

1. Primary infection that spread into bloodstream
2. Does not occur suddenly out of nowhere

Question 5

How do we detect bacteraemia / septicaemia (can be used for bacteria & candida) for patient without a central line in their body?

Answer 5

1. 2 sets of cultures (1 set = 2 bottles, 2 set is 4 bottles, aerobic and anaerobic)
2. 10 ml in each bottle to maximise yield of detecting bacteria or Candida
3. Insufficient blood volume (<5 ml) may lead to false negative/cannot detect the bug

Question 6

What are common pathogens that cause endocarditis?

Answer 6

1. Staphylococci - from IV line/drug use
2. Streptococci (strep viridans, strep bovis)
3. Candida -> enters liver, spleen, eyes easily

Question 7

What are the samples to send for endocarditis?

Answer 7

1. 3 sets of 2 blood cultures (10ml each) = 6 bottles BEFORE antibiotics are given
2. Confirm causative pathogen (all should grow same pathogen)
3. Increase chances of growing pathogen