CA-MRSA Skin InfectionCA-MRSA Skin Infection

Ann McBride, M.D.Ann McBride, M.D.

June 9, 2004June 9, 2004

No financial disclosuresNo financial disclosures

HUGE thanks to Patty BoyleHUGE thanks to Patty Boyle

17 yo high school student, daughter of UW surgeon, with MRSA furunculosis

36 yo F 6 wks after hysterectomy developed extensive furunculosis and skin abscess

51 yo Type 1 DM with chronic neurodermatitis, 2 mos after hospitalization for CAP has + MRSA skin lesions.

OBJECTIVESOBJECTIVES

Clinical Characteristics CA-MRSA Biological Characteristics CA-MRSA Treatment of MRSA Skin Infection Prevention of Recurrences

Major Staph clinical syndromes :

skin-related infections, cellulitis,

osteomyelitis, septic arthritis, TSS,

pneumonia

Transmission: person-to-person contact

from individual with Staph infection or

colonization.

Can be transmitted from contact with contaminated

environment. Can remain days (more than a week)

Airborne transmission is prob not frequent route

S aureus frequently part of transient flora.

Among healthy individuals, carrier rates

est 10 – 30%

Common carrier sites of S.aureus :

anterior nasal vestibule

skin - axilla, perineum- hair, nails

Duration of carrier state – several months

Mean duration 8-9 months; can last years

Hospital personnel and individuals with

chronic skin condition often have higher

rates and longer duration of colonization

MRSA first described nosocomial pathogen 1960’s

MRSA = ORSA

resistance to all B-lactams, & cephalosporins

1990’s CA-MRSA vs HCA-MRSA

CA-MRSACA-MRSA(excludes dx of HCA-MRSA)(excludes dx of HCA-MRSA)

1. Dx in outpt setting or culture + MRSA within 48 hrs after hospital admission

2. No history previous MRSA

3. No hospitalization or exposure to health care facility within previous year

4. No permanent indwelling catheter

In 2000 CDC surveillance to

characterize clinical, micro-

biological, and molecular features

of CA-MRSA and HCA- MRSA

JAMA Dec 2003

Comparison of CA-MRSA vs HCA-MRSA

12 labs in MN

½ metropolitan

½ non-metro

All labs served inpt and outpt

10/12 Adults and Peds

1/12 Peds only

MN Surveillance:MN Surveillance:

¼ all S. aureus cultures = MRSA¼ all S. aureus cultures = MRSA 1100/46121100/4612 Range 10-49%Range 10-49%

Among MRSA:Among MRSA: 85% HCA85% HCA 12% CA12% CA 3% unclear3% unclear

MN Surveillance:MN Surveillance:

Of CA-MRSAOf CA-MRSA 53% metropolitan53% metropolitan 47% non-metro47% non-metro

Younger median age of CA-MRSA vs HCA-Younger median age of CA-MRSA vs HCA-MRSAMRSA

30 yo vs70 yo30 yo vs70 yo

mecA gene required for MRSAmecA gene required for MRSAmecA gene codes PBP 2amecA gene codes PBP 2a

Pcn Binding Protein low affinity Pcn Binding Protein low affinity for for B-lactams Thus, more B-lactams Thus, more resistant resistant to B-lactams.to B-lactams.

Difference in exotoxin genes between CA- and HCA MRSA

PVL (Panton Valentine Leukocidin) gene: * common in CA MRSA (20/26 vs. 1/26) esp. skin infections, necrotizing

pneumonia * codes for Cytotoxin disrupts cell membrane;

cause severe tissue necrosis, destruction WBCs

* facilitates MRSA penetration of intact skin

Frequency of MRSA colonization

not addressed ** 500 otherwise healthy children

seen UCCH 1996; 132 colonized with S. aureus

11/132 (8.3%) were MRSA

Pt #1 17 yo recurrent furunculosis Fall 2003

Dau of UW surgeon abscess L arm +MRSA

dau’s skin wound & nares culture +MRSA

- DM, Skin dz, needle use

hs swim team; no skin infctn among teammates

2 households – only father and my pt +MRSA

grandmother in nursing home

Impr: colonized w/ MRSA and recurrent furunculosis

Management: Decolonization

End of swim team participation

Treatment of recurrent furuncles

--minocycline + rifampin x 2 wks

Decolonization for CA-MRSA Decolonization for CA-MRSA

Generally NOT recommended for single case MRSA infection

Consider for recurrent MRSA infection

(3 or more infections in 6 months)

DecolonizationDecolonizationMupirocin ointment anterior nares “match Mupirocin ointment anterior nares “match head size”head size”

½ anterior vestibule one nostril½ anterior vestibule one nostril½ anterior vestibule other nostril½ anterior vestibule other nostril

Press sides of nose togetherPress sides of nose togetherGently massageGently massage

bid x 5 days (to 14??); one week later f/u bid x 5 days (to 14??); one week later f/u nasal culturenasal culture if nasal culture +MRSA if nasal culture +MRSA repeat once repeat once no more than 3 mupirocin treatmentsno more than 3 mupirocin treatments

Purell hand cleansing

Bath/shower daily with antiseptic

Wet skin thoroughly

Body wash – chlorhexidine (Rx Hibiclens)

Apply disinfectant soap with moistened face cloth

Caution: Skin irritation

? Substitute tree oil cleanser

Pat skin dry gently; avoid abrading skin Use moisturizer while skin is moist after

bathing Consider D/C shaving temporarily Avoid tightly fitting clothes/bands

could rub skin

EnvironmentEnvironment

Launder

– Hot water

– Bed sheets, towels, wash cloths

Dryer (med to high heat) for clothes -- not air drying

Wipe down bathroom and kitchen counters, and handles –refrigerator, doors, cabinets (bleach)

Outbreaks CA-MRSA described in various populations including participants in sports.

Risk factors for Staph infections in athletes:

Contact with lesions of other players

Skin trauma

Sharing of sports equipment

CDC’s Recommendations for CDC’s Recommendations for Preventing Staph InfectionsPreventing Staph Infections

1. Cover all wounds. If a wound cannot be covered adequately, consider excluding player until lesions healed

2. Encourage good hygiene—showering w/ soap after all practices and competitions

3. Ensure availability of soap and hot water

4. Discourage sharing of towels, clothing, and equipment

5. Establish routine cleaning schedule for shared equipment

6. Educate athletes and coaches re: potentially infectious skin lesion

7. Encourage early reporting/assessment for skin lesions

With recurrence

minocycline + rifampin

clindamycin + rifampin

TMP-SMX + rifampin

Minocycline has excellent skin penetration

Rifampin + atbtc to reduce emergence of resistance

Lecture by Dr. Maki

If furuncle appears to develop, apply liberal amount of OTC Bacitracin ointment

Apply Tegaderm (Transparent polyurethene dressing)

This maintains high concentration of drug in lesion x 3-4 days

Pt #2 36 yo woman undergone Pt #2 36 yo woman undergone hysterectomyhysterectomy

late summer 2003. Developed “bug late summer 2003. Developed “bug bites”bites”

buttocks and thighs fall 2003buttocks and thighs fall 2003

Gyn treated ceph Gyn treated ceph

Next day, came to IM “no better” ; R Next day, came to IM “no better” ; R leg furuncle had small amt of purulent leg furuncle had small amt of purulent drainagedrainage

Diclox initiated, skin lesion +MRSADiclox initiated, skin lesion +MRSA

RTC 48 hrs; Lesion had drained and improved RTC 48 hrs; Lesion had drained and improved after draining.after draining.

Diclox D/C’d; No systemic antibioticDiclox D/C’d; No systemic antibiotic

Decolonization effort and topical/local Decolonization effort and topical/local treatment of recurrence per Dr. Maki’s treatment of recurrence per Dr. Maki’s recommendationrecommendation

One additonal lesion, did not require po atbtcOne additonal lesion, did not require po atbtc

F/up surveillance cultures negative x 3F/up surveillance cultures negative x 3

+ MRSA Patient Presenting to Clinic+ MRSA Patient Presenting to Clinic

Pt placed directly into exam room

–Need not be negative flow

–Door may remain open

–Gown, gloves required if touching pt or any item in room

–Mask not usually required (unless +MRSA nares w/ URI)

Gown, gloves left in room

Stethoscope cleansed with ETOH

Purell hand cleansing before exiting

Room closed until housekeeping cleanses/disinfects

MRSA precautions in clinic cannot be lifted until three sets of neg surveillance cx

On order card check “MRSA Screen” Each set obtained at least one week apart Swabs from L & R nares combined (single

swab for both nares) Swabs from axilla and groin can be

combined (single swab for both axillae and both sides of groin)

No role for attempting mupirocin or systemic

(oral antibiotics) decolonization in pt with

chronic skin condition

Patient #3

50 yo Type 1 DM w/ neurodermatitis chronically excoriated skin

hospitalized Nov 2002 with pneumonia

In Dec 2002, MD in neuroderm clinic +MRSA arm lesion

Early 2003 – appt in IM Clinic; WISCR = +MRSA

No attempt to decolonize

2003 – 2 small skin abscesses

I & D; Consult w/ ID- rec decolonization attempt to decrease bioburden

Decolonization effort has worsened dermatitis

Three patients -- all three “HCA-MRSA” --

yet clinical presentation assoc with CA-;

atbtc susc pattern ‘typical’ for CA-MRSA

Clinical importance/helpfulness of this distinction???

Clinical setting most predictive of S aureus infection.

Clinical syndromes CA-MRSA – typically,

skin infections, cellulitis, abscess – closely

resemble clinical syndrome of MSSA in

community

Atbtc selection depends upon susc pattern

Management Future – PCR testing for mecA gene to est MRSA sooner??