Ruma Srivastava and Nicole Hauck

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S. aureus Colonization and Intervention in
Children with Skin and Soft Tissue Infections

• Ruma Srivastava and Nicole Hauck
• Mentor Janak Patel

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Overview

• Emerging problem of community-acquired S. aureus
  infections in children
• Study objectives
• Methods
• Results
• Conclusions

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The Many Threats of S. aureus
Furuncle or Carbuncle Cellulitis Surgical Wound
Infection Pyomyositis Bacteremia Endocarditis Oste
omyelitis Septic Arthritis Epidural
Abscess Pneumonia Empyema Septic Shock Toxic
Shock Syndrome Scalded Skin Syndrome Food-Borne
Gastroenteritis
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S aureus SuperBug
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Community-Acquired S. aureus

• Emerging cause of infection in otherwise healthy
  children. Recent studies have shown 70 increase
  in incidence rates.
• Better fitness and replicates more rapidly than
  hospital-acquired strains resulting in increased
  transmission.
• More virulence factors than hospital acquired
  strains associated with severe, rapidly
  progressive infections.

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Trends in Rates of Antibiotic Resistance in
CA-SAAges 0- 18 yrs3/00 10/02n1,320
63
UTMB Resident Project Champaign, Readinger and
Patel 2003
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Role of Colonization

• The primary habitat has been universally accepted
  to be the moist squamous epithelium of the
  anterior nares.
• S. aureus carriage has long been known to be one
  of the most strongly associated risk factors for
  subsequent infection.
• Studies addressing nasal colonization are based
  primarily on hospitalized and ill patient
  populations.

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Decolonization

• Believed to be an important strategy to prevent
  invasive S. aureus infections
• Eradication Strategies
• Antiseptic snuffs
• Methicillin inhalation
• Mupirocin
• Oral antibiotics
• Bacterial Interference
• Antibacterial baths
• Combination treatments

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Critical Gap in Knowledge

• In patients with recurrent community-acquired S.
  aureus infections, the actual site of
  colonization has not been studied
• Modes of prevention of recurrences have not been
  studied
• Skin or nasal decontamination procedures are
  often done, but there are no published studies of
  efficacy
• Dr. Patel at UTMB and Dr. Kaplan at TCH have
  routinely used skin decontamination protocol to
  prevent recurrences (not nasal decontamination)

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HYPOTHESES

• The primary site of colonization with S. aureus
  in children with community-acquired infection is
  the skin rather than the anterior nares
• Skin decontamination is efficacious in preventing
  recurrences of SSTI

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Specific Aims

• To determine the sites of S aureus (SA)
  colonization among children with
  community-acquired skin and soft tissue
  infections (SSTI)
• To determine the effect of topical
  decontamination of skin with povidone (Betadine)
  wash on the future recurrence rate of SSTI.

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Study design

• Aim 1 Prospective observational study of
  colonization
• Aim 2 In a cohort of subjects with recurrent
  SSTIs
• Prospective single-arm interventional study of
  success of skin decontamination and comparison
  against pre-intervention rates of occurrence

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Subject Enrollment

• Recruitment Sites
• Childrens Hospital Inpatient Floors, Primary
  Care Pediatric Clinic, and the Emergency
  Department
• Inclusion Criteria
• Consenting patients from 6 mos to 18 yrs of age
  with Community-acquired SSTI
• Infants less than 6 months were excluded for
  concern for povidone toxicity by skin absorption
  (IRB requirement)
• Exclusion Criteria
• Hospital acquired infection Children with
  permanent indwelling catheters or medical devices
  or a medical history in the past year of
  hospitalization , admission to a skilled nursing
  facility, nursing home or hospice, dialysis,
  surgery
• other than for treatment of Staphyloccal skin
  and soft tissue infections.

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METHODS..1

• Permission obtained from the UTMB Institutional
  Review Board to conduct the study
• Written consent obtained from parents and assent
  from patients gt 7 yrs old.
• Demographic and clinical data regarding the
  current infection and history of prior infections
  was obtained by interview and chart review.

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Methods..2

• Subjects were defined as having recurrent SSTIs
  if they had 2 or more past episodes over a
  preceding 6 month period
• Moistened culturette was used to swab the
  anterior nares, axillae, groin and wound site of
  each patient.
• The swabs were sent to the laboratory for
  bacteriologic culture and susceptibility.

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• Patient Instruction Handout
• Betadine Body Wash Instructions
• Mix ½ cup of Povidine (Betadine)
  with 2 cups of water
• Apply all over body, except around eyes, using a
  washcloth.
• Let it dry for 3 minutes.
• Take a normal shower
• REPEAT TWICE PER WEEK FOR TWO WEEKS
• Note synthetic fibers such as polyester and
  nylon can become stained with Betadine.

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Follow-up

• Patients were contacted by phone and letter at 3
  and 6 months post-enrollment to request
  information about recurrent infections.
• The follow up questionnaire included questions
  regarding
• - subsequent skin/soft tissue infections
• - treatment of subsequent infections
• - infections in the family members
• - use of the povidone body wash
• - parent opinion regarding body wash
• Patient charts were reviewed for further evidence
  of recurrent infection

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Results

• 29 Patients with SSTI were approached
• 3 were excluded due to likelihood of hospital
  acquired infection
• 2 patients refused participation
• 24 patients were enrolled

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Demographic Characteristics
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Clinical Characteristics
Defined as 2 or more previous infections
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Wound Culture Results
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Median Age 2.1y
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T
T total of 9 patients
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Post-Intervention
one pt. was admitted with a recurrent infection
due to surgical would infection of a
supracondylar fracture requiring pins at 6 months
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Post-Intervention
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Follow-up
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Follow-up Intervention Data
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Effect of Intervention on Monthly Recurrence Rate

• 38
• Before bodywash

2 After bodywash
vs.
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Conclusions

• The primary site of colonization in children with
  CA-SA is the skin and not the anterior nares.
• Decontamination of the skin with topical
  antibacterial agents is an effective intervention
  for the prevention of recurrences.

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Future Research

• Large, randomized controlled trial with
  recruitment in various clinical settings.
• Molecular confirmation of relatedness between
  infecting and colonizing strains.

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Acknowledgements

• Janak Patel, M.D.
• Jose Gonzalez, M.D.
• Nahed Ismail, M.D., M.Sc., Ph.D.
• Sharon Petronella, Ph.D
• Erik Hauck, M.D., PhD.