Methicillin-Resistant Staphylococcus aureus (MRSA) A new challenge for a new century Laura L. Radke,...

Methicillin-Resistant Methicillin-Resistant Staphylococcus aureus Staphylococcus aureus

(MRSA)(MRSA)

A new challenge for a new centuryA new challenge for a new centuryLaura L. Radke, MDLaura L. Radke, MD

March 5March 5thth, 2008, 2008

HistoryHistory

Initially appeared in hospitals in the 1960’s – Initially appeared in hospitals in the 1960’s – Healthcare associated (HA MRSA)Healthcare associated (HA MRSA)

Highly resistant to commonly used antibioticsHighly resistant to commonly used antibiotics Risk factors included:Risk factors included:

HospitalizationHospitalization Nursing Home residenceNursing Home residence Chronic dialysisChronic dialysis Antibiotic useAntibiotic use Use of invasive devices and/or proceduresUse of invasive devices and/or procedures

HistoryHistory

Associated with increased morbidity and Associated with increased morbidity and mortalitymortality

Also associated with increased healthcare Also associated with increased healthcare costs related to prolonged hospital stays, costs related to prolonged hospital stays, courses of intravenous antibiotics for courses of intravenous antibiotics for treatment and lost productivitytreatment and lost productivity

Capable of colonizing nares of healthcare Capable of colonizing nares of healthcare workers and causing hospital outbreaksworkers and causing hospital outbreaks

HistoryHistory

In the 1990’s, infections with MRSA began In the 1990’s, infections with MRSA began to emerge in persons without risk factors to emerge in persons without risk factors for HA MRSAfor HA MRSA

New type of MRSA identified – Community New type of MRSA identified – Community associated MRSA (CA MRSA)associated MRSA (CA MRSA)

Defined as infection in a person with no Defined as infection in a person with no prior history of health care exposure, i.e. prior history of health care exposure, i.e. hospitalization, surgery, permanent hospitalization, surgery, permanent devices or hemodialysisdevices or hemodialysis

Characteristics of CA MRSACharacteristics of CA MRSA

Genetically different from HA MRSAGenetically different from HA MRSA Contains mec IV resistance chromosomeContains mec IV resistance chromosome Less resistant, more susceptible to more Less resistant, more susceptible to more

classes of antibioticsclasses of antibiotics Carries the Panton Valentine Leukocidin Carries the Panton Valentine Leukocidin

(PVL) gene(PVL) gene Allows production of necrotizing cytotoxinAllows production of necrotizing cytotoxin May be responsible for increased invasiveness of May be responsible for increased invasiveness of

the organizmthe organizm

Characteristics of CA MRSACharacteristics of CA MRSA

Typically causes skin and soft tissue Typically causes skin and soft tissue infectionsinfections Early lesions look like spider bitesEarly lesions look like spider bites Often present with boils, abscesses or Often present with boils, abscesses or

cellulitiscellulitis

Can cause more serious infections such Can cause more serious infections such as bacteremia, pneumonia, wound and as bacteremia, pneumonia, wound and surgical site infectionssurgical site infections

Comparison of HA Comparison of HA MRSAMRSA and CA and CA MRSAMRSA

“Community Associated Methicillin Resistant StaphyococcusAureus (CA MRSA) –Guidelines for Management and Control of Transmission”, PPH 42160, October 2005, Wisconsin DFHS

Epidemiology of CA MRSAEpidemiology of CA MRSA

Wide geographic variation in infection Wide geographic variation in infection ratesrates

Incidence in Wisconsin is unknownIncidence in Wisconsin is unknown Generally, < 1% of populationGenerally, < 1% of population Based on personal experience, appears to Based on personal experience, appears to

be increasingly more frequentbe increasingly more frequent Native Americans, Pacific Islanders and Native Americans, Pacific Islanders and

Alaskan natives appear to be more Alaskan natives appear to be more susceptiblesusceptible


Transmission is primarily person-to-person Transmission is primarily person-to-person Can occur through indirect contact with Can occur through indirect contact with

contaminated surfaces and itemscontaminated surfaces and items Outbreaks have occurred among sports Outbreaks have occurred among sports

team members, prisoners, military recruits, team members, prisoners, military recruits, men having sex with men and IVDU’smen having sex with men and IVDU’s

Transmission has also occurred in Transmission has also occurred in hospitals among postpartum women and hospitals among postpartum women and orthopaedic surgery patientsorthopaedic surgery patients


Nasal carriage not as common as with HA Nasal carriage not as common as with HA MRSAMRSA

Recent nasal colonization associated with Recent nasal colonization associated with 10-fold risk of developing skin and soft 10-fold risk of developing skin and soft tissue infectiontissue infection

Previous colonization may confer some Previous colonization may confer some immunity and decrease risk for immunity and decrease risk for development of invasive diseasedevelopment of invasive disease

Risk Factors for CA MRSA Risk Factors for CA MRSA InfectionInfection

History of MRSA infection or colonization History of MRSA infection or colonization of pt. or close contactof pt. or close contact

High prevalence of CA MRSA in local High prevalence of CA MRSA in local communitycommunity

Recurrent skin disease, i.e. eczema, Recurrent skin disease, i.e. eczema, dermatitisdermatitis

Crowded living conditions, i.e. military Crowded living conditions, i.e. military barracks, homeless shelterbarracks, homeless shelter


History of or current incarcerationHistory of or current incarceration Participation in contact sportsParticipation in contact sports Skin/soft tissue infection with poor Skin/soft tissue infection with poor

response to B-lactam antibioticsresponse to B-lactam antibiotics Recent/frequent antibiotic useRecent/frequent antibiotic use IVDUIVDU Native American, Pacific Island or Alaskan Native American, Pacific Island or Alaskan

Native ethnicityNative ethnicity


Child under the age of 2Child under the age of 2 Male with history of having sex with menMale with history of having sex with men Shaving of body hair, especially extensive Shaving of body hair, especially extensive

shaving of arms and/or legs related to shaving of arms and/or legs related to sports participationsports participation

Presentation of CA MRSA InfectionPresentation of CA MRSA Infection

Skin and soft tissue infectionSkin and soft tissue infection AbscessesAbscesses Pustular lesionsPustular lesions BoilsBoils Lesions resembling “spider bites”Lesions resembling “spider bites”

More severe disease compatible with Staph More severe disease compatible with Staph infectioninfection OsteomyelitisOsteomyelitis Necrotizing pneumoniaNecrotizing pneumonia Septic arthritisSeptic arthritis Necrotizing fasciitisNecrotizing fasciitis

Management of CA MRSA Management of CA MRSA

Incision and drainage of abscessesIncision and drainage of abscesses Should be the primary treatmentShould be the primary treatment Often the only treatment necessaryOften the only treatment necessary

Material sent for cultureMaterial sent for culture Instruct patients to return for:Instruct patients to return for:

worsening local symptomsworsening local symptoms no improvement in 48-72 hoursno improvement in 48-72 hours signs/symptoms of systemic illnesssigns/symptoms of systemic illness


Outpatient antibiotic therapyOutpatient antibiotic therapy Based on local prevalence of MRSABased on local prevalence of MRSA Severity of illnessSeverity of illness Patient comorbidityPatient comorbidity

Antibiotic choicesAntibiotic choices Topical mupirocin 2% or bacitracin for local infectionTopical mupirocin 2% or bacitracin for local infection Trimethoprim/SulfamethoxazoleTrimethoprim/Sulfamethoxazole

Most frequent antibiotic with sensitivity in vitroMost frequent antibiotic with sensitivity in vitro May penetrate abscesses poorly, i.e. less effective for May penetrate abscesses poorly, i.e. less effective for

undrained abscessesundrained abscesses


Antibiotic choices, cont.Antibiotic choices, cont. Clindamycin for sensitive organismsClindamycin for sensitive organisms

Must be sensitive to both erythromycin and Must be sensitive to both erythromycin and clindamycin – requires D test (St. Joe’s lab clindamycin – requires D test (St. Joe’s lab performing regularly)performing regularly)

Inducible resistance appears to be increasingInducible resistance appears to be increasing

Tetracycline/Doxycycline for sensitive Tetracycline/Doxycycline for sensitive organismsorganisms Less intrinsic antistaphylococcal activityLess intrinsic antistaphylococcal activity


Antibiotic choices, cont.Antibiotic choices, cont. Macrolides and Fluoroquinolones are not Macrolides and Fluoroquinolones are not

appropriate treatment for CA MRSAappropriate treatment for CA MRSA Even if susceptible in vitro, may be ineffective in Even if susceptible in vitro, may be ineffective in

vivovivo Rapid development of resistance can occurRapid development of resistance can occur

Patient education is essential!Patient education is essential! Review wound care, hand washing and Review wound care, hand washing and

hygiene at homehygiene at home

“Community Associated Methicillin Resistant StaphyococcusAureus (CA MRSA) –Guidelines for Management and Control of Transmission”, PPH 42160, October 2005, Wisconsin DFHS

Management of CA MRSAManagement of CA MRSA

DecolonizationDecolonization Routine use of mupirocin intranasally is not Routine use of mupirocin intranasally is not

recommendedrecommended Resistance to mupirocin has begun to emergeResistance to mupirocin has begun to emerge Can be considered in patients with recurrent Can be considered in patients with recurrent

infections or in household where several infections or in household where several members have had skin/soft tissue infectionsmembers have had skin/soft tissue infections

Family contacts should not be routinely Family contacts should not be routinely screenedscreened


DecolonizationDecolonization Patients with nasal colonization can be Patients with nasal colonization can be

treated with 2% intranasal mupirocin for 5 treated with 2% intranasal mupirocin for 5 daysdays

Daily bathing/showering using chlorhexidine Daily bathing/showering using chlorhexidine gluconate and/or tea tree oil is recommended gluconate and/or tea tree oil is recommended along with mupirocin treatmentalong with mupirocin treatment


DecolonizationDecolonization Oral or IV antibiotics should not be routinely Oral or IV antibiotics should not be routinely

administeredadministered Short courses of po antibiotics may assist in Short courses of po antibiotics may assist in

decolonization; repeated courses should not be decolonization; repeated courses should not be givengiven

Follow-up cultures are not recommended Follow-up cultures are not recommended unless recurrent infections are notedunless recurrent infections are noted

Prevention of Transmission of CA Prevention of Transmission of CA MRSAMRSA

Healthcare settingsHealthcare settings Contact precautions should be used for all Contact precautions should be used for all

patients with known MRSA infectionspatients with known MRSA infections Contact precautions should also be used for Contact precautions should also be used for

all patients with skin/soft tissue infections all patients with skin/soft tissue infections compatible with a diagnosis of Staph infection compatible with a diagnosis of Staph infection and for all patients with uncontained and for all patients with uncontained secretions/wound drainagesecretions/wound drainage


Community settingsCommunity settings More studies needed to determine best More studies needed to determine best

methodsmethods Increased awareness by healthcare providersIncreased awareness by healthcare providers Early detection, including screening of Early detection, including screening of

inmates, military recruits, sports participants, inmates, military recruits, sports participants, shelter residents, close contacts of known shelter residents, close contacts of known MRSA casesMRSA cases

Appropriate treatment when risk factors are Appropriate treatment when risk factors are present/suspicion is highpresent/suspicion is high


Community settingsCommunity settings Improved personal hygieneImproved personal hygiene Environmental cleanliness in gyms, spas, Environmental cleanliness in gyms, spas,

health clubshealth clubs Improved hygiene amongst participants in Improved hygiene amongst participants in

contact sportscontact sports Improved hand hygiene in schools and work Improved hand hygiene in schools and work

settingssettings

Methicillin-Resistant Staphylococcus aureus (MRSA) A new challenge for a new century Laura L. Radke,...

Documents

Transcript of Methicillin-Resistant Staphylococcus aureus (MRSA) A new challenge for a new century Laura L. Radke,...