Staph aureus bacteraemia Flashcards

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1
Q

Initial management of suspected SAB is basic management for sepsis.

What are potential sites S aureus likes to infect

A
Skin
Bone - need MRI
IE
Prosthesis - cannula, haemodialysis, urinary catheter/ ICD
IVDU - abscess/ septic DVT

Rarer sources:
Pneumonia
UTI

Consider recent hospitalisation as increased risk factor

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2
Q

What will initial examination involve?

A

Check skin - cellulitis/ ulcers/ abscess
Check joints/ spinal tenderness
Heart murmurs/ peripheral stigmata IE
Devices - cannula/ catheter

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3
Q

Which patients recommended to have TTE in SAB?

A

If focus cannot be identified, then should all have ECHO.

Many patients may need ECHO if not improving, as SAB can seed to valves

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4
Q

Which patients should have TOE?

A

If high risk IE, source unknown, TTE negative

Persistent bacteraemia >4 days

Permanent cardiac device

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5
Q

Before starting treatment, we should assess for risk of MRSA. What are risk factors?

MRSA is not more likely to infect than MSSA, just harder to treat

A

Check MRSA swab results previous admission

Recent history of hospitalisation 3 months

Regular hospital visits - e.g dialysis

Indwelling prosthesis - Hickman line

Care home resident

Chronic ulcers

IVDU

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6
Q

What is initial empirical therapy for SAB?

A

MSSA - flucloxacillin 2g QDS
MRSA - vancomycin/ teicoplanin/ daptomycin/ tigecycline

If high risk MRSA, treat with vancomycin

Empirical treatment also involves removing infected device/ draining abscess/ joint washout

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7
Q

What is treatment duration for SAB?

A

2 weeks IV if uncomplicated. Uncomplicated includes no IE, negative repeat cultures, cannula removed

Septic arthritis - 4 weeks total (min 2 weeks IV)
IE/ osteomyelitis - 6 weeks total (min 2 weeks IV)

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8
Q

Vancomycin for MRSA - what are target levels?

A

15-20mg/L for MRSA/ deep seated infection

Normal uses of vancomycin have acceptable levels between 10-20mg/L

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9
Q

If not responding to vancomycin, what are next steps?

A

If levels OK, do not increase dose

Switch agent e.g teicoplanin

Perform vancomycin resistance testing with E-test

Search/ remove source

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10
Q

Referral phones asking for advice about SAB - what do you tell them to do

A

Examine for source

Investigate/ source control -

  • MRI - spine/ joints
  • ECHO
  • doppler USS

Treat antibiotics

Repeat blood cultures after 72 hours

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11
Q

MRSA skin infection (no bacteraemia) - what are treatment options

MRSA UTI (no bacteraemia) - what are treatment options

A
Skin -
Co-trimoxazole
Clindamicin
Doxycycline
Linezolid

UTI -
trimethoprim
nitrofurantoin

If not improving -
Vancomycin
Teicoplanin
Daptomycin
Tigecycline
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12
Q

Why are quinolones avoided if suspecting staph aureus infection?

A

ciprofloxacin/ levofloxacin are to be avoided because rates of MRSA infection are increased in hospitalized patients treated with quinolones

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13
Q

When treating cellulitis, and you are suspecting staph aureus, what other organisms should you be vary of?

A

Group A Strep

Co-trimoxazole/ doxycycline you may use for staph skin infection, are less effective against GAS

clindamicin is effective against GAS/ S aureus

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14
Q

SAB does not need isolated. But if patient MRSA swab is positive, then they need isolated. Those with open wounds/ devices have higher risk of spreading MRSA.

All admissions are screened for MRSA

What is decolonisation treatment?

A

Bactroban - mupirocin 2% - nasal BD for 5 days. Must be limited to two courses, as shown to develop resistance after this.

Chlorhexidine wash 4% - OD body wash 5 days,
Day 1/ day 5 hair wash

Re-screen two days after treatment
Re-screen five days after treatment

No longer considered colonised if 2 repeat screens negative

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15
Q

If MRSA decolonisation fails, what are options?

A

octenisan daily wash

neomycin nasal cream (naseptin) for 5 days. Avoid if nut allergy

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16
Q

When isolated in side room, what precautions should be taken?

A

PPE
5 moments hand hygiene
Only essential staff entering

17
Q

MSSA/ MRSA can produce a toxin called PVL (Panton Valentine Leucocidin). <2% of Staph aureus infections are PVL

What effect does it have?

A

Toxin forms pores on neutrophil membranes, lysing them

18
Q

What are clinical features of PVL-SA?

A

Boils - particularly recurrent/ more than one household member
Folliculitis
Necrotic skin lesions
Necrotising fasciitis
Necrotising pneumonia - commonly have flu-like illness preceeding it
Osteomyelitis

Failure on treatment for MSSA

19
Q

What are risk factors for PVL-SA?

A

CDC 5Cs

Cleanliness
Close contact
Crowding
Cleanliness
Cuts

Nursing home
Military camps
IVDU
Close contact sport - rugby, judo

20
Q

What is treatment for

PVL-MSSA - SSTI

PVL-MRSA - SSTI

A
PVL-MSSA - 
flucloxacillin
doxycycline
clindamicin
co-trimoxazole
PVL-MRSA - 
doxycycline
clindamicin
rifampicin + fusidic acid
rifampicin + trimethoprim

Incision and drainage of boils is optimal treatment

21
Q

What is treatment for severe PVL-SA infection?
MSSA + MRSA

Toxic shock
Necrotising pneumonia
Purpura fulminans

A

Clindamicin + linezolid

Urgent surgical debridement is key

22
Q

What is treatment for deep seated infections

PVL-MSSA

PVL-MRSA

A

PVL-MSSA -
Clindamicin + linezolid
Clindamicin + rifampicin

PVL-MRSA
Vancomycin + sodium fusidate
Vancomycin + gentamicin
Vancomycin + rifampicin

23
Q

All patients with PVL-SA should be isolated.

If have PVL pneumonia, what precautions must be taken?

What is decolonisation procedure?

A

Respiratory precautions

Same as for MRSA