Evaluation of the Occurrence and Risk of Microbes in Laundry and Laundry-Associated Surfaces

Persistent Link:
http://hdl.handle.net/10150/194201
Title:
Evaluation of the Occurrence and Risk of Microbes in Laundry and Laundry-Associated Surfaces
Author:
Nordstrom, Jeanne McDonald
Issue Date:
2009
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Viable bacteria have been found on environmental surfaces, including washed and unwashed clothing, and places that come into contact with laundry. Under certain conditions, clothing contaminated with pathogenic organisms may present a health risk to the laundry handler. This research project focused on i) evaluating Staphylococcus aureus and MRSA survival using front-load and top-load washing machines; ii) determining relative microbial levels on new, disposable, laundered and unlaundered hospital scrubs; iii) characterizing the relative hygiene of public and apartment laundromat surfaces; and iv) developing a quantitative risk assessment for laundry handlers.Standard microbial evaluation techniques were used to identify and quantify a variety of microorganisms on fabrics and environmental surfaces, including HPC bacteria, S. aureus, MRSA, total coliforms and Escherichia coli. S. aureus and MRSA were exclusively used during evaluation of bacteria reduction levels achieved by front- and top-load washers.Results from this research indicate:i) Washing in either a top- or front-load washer affords a 5 - 6 log10 reduction of S. aureus and MRSA when detergent is used. If complete drying and/or bleach are also employed, a 6 - 7 log10 reduction is achieved and few organisms remain.ii) Bacteria cross-contamination of other fabrics within a laundry load is common for both types of washers and between loads on the interior of top-load washers.iii) Significantly fewer bacteria (p=0.044) were detected on hospital-laundered scrubs than on home-laundered scrubs.iv) Laundromat surfaces can be contaminated with substantial numbers of bacteria and the potential exists for transfer of bacteria from a past user to the next laundromat patron.v) The risk of acquiring a S. aureus infection after handling unwashed laundry contaminated with an initial S. aureus level of 106 CFU/cm2 was estimated to be 0.59 infections per person per year. The estimated risk became negligible if handling washed laundry.
Type:
text; Electronic Dissertation
Keywords:
laundromat; laundry; risk; scrubs; Staphylococcus aureus
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Soil, Water & Environmental Science; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Gerba, Charles P.
Committee Chair:
Gerba, Charles P.

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleEvaluation of the Occurrence and Risk of Microbes in Laundry and Laundry-Associated Surfacesen_US
dc.creatorNordstrom, Jeanne McDonalden_US
dc.contributor.authorNordstrom, Jeanne McDonalden_US
dc.date.issued2009en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractViable bacteria have been found on environmental surfaces, including washed and unwashed clothing, and places that come into contact with laundry. Under certain conditions, clothing contaminated with pathogenic organisms may present a health risk to the laundry handler. This research project focused on i) evaluating Staphylococcus aureus and MRSA survival using front-load and top-load washing machines; ii) determining relative microbial levels on new, disposable, laundered and unlaundered hospital scrubs; iii) characterizing the relative hygiene of public and apartment laundromat surfaces; and iv) developing a quantitative risk assessment for laundry handlers.Standard microbial evaluation techniques were used to identify and quantify a variety of microorganisms on fabrics and environmental surfaces, including HPC bacteria, S. aureus, MRSA, total coliforms and Escherichia coli. S. aureus and MRSA were exclusively used during evaluation of bacteria reduction levels achieved by front- and top-load washers.Results from this research indicate:i) Washing in either a top- or front-load washer affords a 5 - 6 log10 reduction of S. aureus and MRSA when detergent is used. If complete drying and/or bleach are also employed, a 6 - 7 log10 reduction is achieved and few organisms remain.ii) Bacteria cross-contamination of other fabrics within a laundry load is common for both types of washers and between loads on the interior of top-load washers.iii) Significantly fewer bacteria (p=0.044) were detected on hospital-laundered scrubs than on home-laundered scrubs.iv) Laundromat surfaces can be contaminated with substantial numbers of bacteria and the potential exists for transfer of bacteria from a past user to the next laundromat patron.v) The risk of acquiring a S. aureus infection after handling unwashed laundry contaminated with an initial S. aureus level of 106 CFU/cm2 was estimated to be 0.59 infections per person per year. The estimated risk became negligible if handling washed laundry.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectlaundromaten_US
dc.subjectlaundryen_US
dc.subjectrisken_US
dc.subjectscrubsen_US
dc.subjectStaphylococcus aureusen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineSoil, Water & Environmental Scienceen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorGerba, Charles P.en_US
dc.contributor.chairGerba, Charles P.en_US
dc.contributor.committeememberReynolds, Kelly A.en_US
dc.contributor.committeememberO'Rourke, Mary Kayen_US
dc.contributor.committeememberWalworth, Jamesen_US
dc.identifier.proquest10340en_US
dc.identifier.oclc659751930en_US
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