Development, Evaluation, and Demonstration of Air Sampling Methods to Assess Airborne Transport of Clostridium Difficile Spores in the Healthcare Environment
Abstract
Clostridium difficile (C. difficile) is a significant healthcare acquired infection worldwide with over 100,000 cases annually in the United States alone. Multiple studies have documented the aerosol generation and airborne dissemination of C. difficile endospores. These endospores are resistant to environmental stresses and have the potential for airborne transport from a source to other areas in a healthcare setting, thus enabling environmental contamination. This study evaluated air sampling methods in the collection of C. difficile aerosol and aimed to: (1) Evaluate low-volume air sampling devices and mechanisms of collection for laboratory-generated aerosols of C. difficile spores; (2) Evaluate the retention of culturable C. difficile spores in impinger air samplers; (3) Evaluate high-volume air sampling devices in the collection of nebulizer-generated C. difficile spore aerosols in a laboratory environment; (4) Demonstrate effectiveness of high-volume air sampling equipment in the collection of C. difficile spore aerosol produced from toilet flushing. In aim 1, mixed cellulose ester (MCE) filters demonstrated significantly higher relative sampling efficiencies compared to slit-to-agar impactor (AirTraceTM) and liquid impinger air samplers (AGI-30 and BioSamplerTM). Both impinger types frequently failed to detect the presence of C. difficile aerosol. In aim 2, impinger operation produced significant culturability losses and failed to retain C. difficile endospores. In aim 3, high volume air sampling using a military Dry Filter Unit 1000 (DFU-1000) resulted in a significantly higher relative sampling efficiency compared to the commercial Biocapture-650, XMX/2L-MIL, and Microbio MB2. In aim 4, high volume air sampling provided a census air sample in a small enclosure similar to a patients bathroom. Toilet flushing from a contaminated toilet generated a mean of 81 colony-forming units during the first three flushes after contamination.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 29, 2019
- Accession Number
- AD1085308
Entities
People
- Casey W. Cooper
Organizations
- Air Force Institute of Technology