Table 1. Comparison between healthcare-associated and community-acquired Methicillin resistant Staphylococcus aureus. Sievert et al. 2013
CA-MRSA HA-MRSA
Clinical spectrum
Skin and soft tissue infections Wound
infections, urinary
tarct infections and bacteraemia
Epidemiology Affected healthy people in the
community Mostly affects hospital patients
Underlying condition
Dernmatological Healthcare associated risk factors
Age group Younger
older
Resistant pattern
Sensitive to multiple antibiotics Resistant to multiple antibiotic
Toxin production
May produce PVL toxin Not yet reported produce PVL toxin
1.3. MRSA testing
MRSA screening may be undertaken for the following reasons: 1. Screening requirement determined from the multidrug Resistant Organism MDRO
Risk Assesment 2. If found positive after admission from a clinical sample
3. As part of Outbreak Management MRSA specimens
A purple bacterial swab is use to sample the following sites: 1. Nasal swab one swab for both nostrils
2. Groin swab one swab for both sides 3. Perineum swab
4. Wound swab-including decubitus ulcer pressure sore or surgical wound and
device insertion e.g. IV tracheostomy, drain, suprapubic 5. Additional site:
Umbilicus in neonates Catheter urine specimen if patient for screening has an indwelling urinary
catheter Sputum from patient with recent MRSA respiratory tract infection not nasal
colonization
1.4. Care of patient with MRSA:
Placement of patients in single room Treatment procedure applies to all patients and staff who may or may not be
currently receiving systemic antibiotic treatment for MRSA infection Contact Precautions with own toilet facilities if Ensuite not available, allocate own
commode chair in room or dedicated toilet
Hand hygiene with antimicrobial liquid soap or alcohol- based hand rub Dedicated patient-care equipment or disinfect between use if shared with other
patients e.g. blood pressure and oximetry equipment Remove unnecessary equipment from the isolation room and ensure supplies are
not overstocked within the room If no Ensuite shower is available the patient showers last in the communal shower
and the shower is disinfected after use Mupirocin Bactroban is to be applied to the anterior nasal nares three times a
day Tridosan 1 is to be used for daily washing of skin and bathing. Cetrimide
shampoo for hair washing twice weekly Treatment is to be for an initial period of seven days
Visitors do not wear PPE but are encourage to perform hand hygiene after visiting the patient
Where possible, permanent staff should be used
Treatment Patients who are severely ill or have a rapidly progressing infection should be referred to
the hospital for consideration of intravenous antibiotics. Intravenous vancomycin is the most commonly used antibiotic for this indication. Vancomycin can have serious side
effects, especially in elderly persons. These side effects could include ototoxicity loss of hearing or other auditory damage, nephrotoxicity damage to the kidneys or renal
system, and allergic reactions such as fever and rash. Infusion of vancomycin, especially when to rapid, can result in flushing, hypotension, and tachycardia known as the “red man
syndrome”. Vancomycin given by mouth is not absorbed and is not effective against MRSAEmergence of vancomycin-intermediate and vancomycin-resistant MRSA VISA and
VRSA, respectively has been reported, but are uncommon Moran. 2006. Linezolid may offer an alternative to intravenous vancomycin. Recent studies have shown that the
adverse event rate of linezolid is not significantly different than that for vancomycin and that linezolid is an effective agent for SSTIs including those caused by MRSA. Daptomycin
has been used effectively in cases of complicated SSTI and for treatment of CA-MRSA bacteremia. Quinupristindalfopristin is active against MRSA, but is rarely used due to an
adverse-effect profile and potential cross-resistance with clindamycin-resistant strains. Tigecycline is active against MRSA and it has FDA approval for the treatment of skin and
soft tissue infections Rybak. 2005; Moran.2006.
Patients with localized infection and without systemic toxicity may be managed as outpatients with oral medications. Oral antibiotic therapy should be continued until there is
resolution of signs of acute inflammation; this typically occurs within 7-14 days. Options for oral antibiotics include trimethoprim-sulfamethoxazole, clindamycin, linezolid or
tetracyclines eg, minocycline or doxycycline .Moran, 2006; Rybak, 2005.
Access to oral linezolid may be limited due to formulary restrictions and other cost related issues. Some infectious disease specialists save linezolid for use in infections due to
organisms resistant to other agents. This conservative approach is supported by reports of the emergence of linezolid-resistant organisms in healthcare settings Kelly, 2006.
Topical, rather than oral, antibiotics can be used to treat superficial lesions. For instance, topical mupirocin TID for ~7 days has been utilized for treatment of limited impetigo
Stevens, 2005; Swartz 2005. Of note, resistance to mupirocin may develop, but this usually occurs in the setting of prolonged usage. For multiple or larger CA-MRSA lesions,
oral antibiotics are recommended.
These drugs generally have activity against CA-MRSA:
1. Vancomycin Vancocyn® 15 mgkg IV q12 hours 2. Daptomycin Cubicin® 4 mgkg IV daily higher dosages are used for
bacteremiaendocarditis Intravenous or Oral Antibiotics 3. Linezolid Zyvox® 600 mg IV or PO twice daily
4. Clindamycin Cleocin® 900 mg IV q8 hours or 300 –450 mg PO QID
5. Oral Antibiotics • Tetracyclines
• Doxycycline Vibramycin® 100 mg PO twice daily • Minocycline Minocin® 100 mg PO twice daily
• Trimethoprim-sulfamethoxazole Bactrim®, Septra® 1 double-strength with 160 TMP800 SMX tablet twice daily
6. Rifampin Rifadin® 300 mg PO twice daily 7. Topical Antibiotics
• Topical mupirocin Bactroban® apply to each nares twice daily • Chlorhexidine body soaps, shower with soap daily used for decolonization
purposes, not treatment Dosages listed assume normal kidney and liver function; for patients with abnormal
values, drug dosage adjustments may be needed. Some antibiotics listed are not recommended in children or during pregnancy.
1.5. MRSA Treatment in the Setting of Highly Active Antiretroviral Therapy HAART