Longitudinal Case Series of Staphylococcus aureus Colonization and Infection in Two Cohorts of Rural Iowans

Microb Drug Resist. 2018 May;24(4):455-460. doi: 10.1089/mdr.2017.0124. Epub 2018 Jan 3.


Objective: Examine the relationship between colonization with Staphylococcus aureus in the community and symptomatic infection in two cohorts of Iowans.

Design: Case series within cohort study.

Participants: Rural Iowans selected from the Keokuk Rural Health Study, the Agricultural Health Study, and the Iowa Voter Registry.

Methods: Longitudinal study within established cohorts evaluating documented S. aureus infections with samples available for molecular typing.

Results: We examined this relationship in two cohorts of Iowans with a combined 11 incident cases of S. aureus SSTI, for which samples were available. Seven of the 11 individuals (63.6%) were colonized at baseline, in the nose (3/7, 42.9%), or in both the nose and throat (57.1%). All seven cases had matching sequence types between colonization and infection isolates.

Conclusions: Staphylococcus aureus causes millions of skin and soft tissue infections yearly. Although colonization with S. aureus is a frequent antecedent to infection, many studies investigating the link between colonization and infection have taken place in a clinical setting, particularly in urban hospitals. Our study has shown similar results in a rural community setting to those previously seen in clinics.

Keywords: MRSA; antibiotic resistance; epidemiology; skin infection; soft tissue infection.

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents / therapeutic use
  • Carrier State / microbiology
  • Community-Acquired Infections / drug therapy
  • Community-Acquired Infections / microbiology*
  • Female
  • Humans
  • Iowa
  • Longitudinal Studies
  • Male
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification*
  • Middle Aged
  • Nose / microbiology
  • Pharynx / microbiology
  • Risk Factors
  • Rural Population
  • Skin
  • Soft Tissue Infections / drug therapy
  • Soft Tissue Infections / microbiology
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / microbiology*
  • Staphylococcal Skin Infections / drug therapy
  • Staphylococcal Skin Infections / microbiology


  • Anti-Bacterial Agents