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Nguyen TT, He C, Carter R, Ballard EL, Smith K, Groth R, Jaatinen E, Kidd TJ, Thomson RM, Tay G, Johnson GR, Bell SC, Knibbs LD. Quantifying the effectiveness of ultraviolet-C light at inactivating airborne Mycobacterium abscessus. J Hosp Infect 2023; 132:133-139. [PMID: 36309203 DOI: 10.1016/j.jhin.2022.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/26/2022] [Accepted: 10/06/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Mycobacterium abscessus (MABS) group are environmental organisms that can cause infection in people with cystic fibrosis (CF) and other suppurative lung diseases. There is potential for person-to-person airborne transmission of MABS among people with CF attending the same care centre. Ultraviolet light (band C, UV-C) is used for Mycobacterium tuberculosis control indoors; however, no studies have assessed UV-C for airborne MABS. AIM To determine whether a range of UV-C doses increased the inactivation of airborne MABS, compared with no-UVC conditions. METHODS MABS was generated by a vibrating mesh nebulizer located within a 400 L rotating drum sampler, and then exposed to an array of 265 nm UV-C light-emitting diodes (LED). A six-stage Andersen Cascade Impactor was used to collect aerosols. Standard microbiological protocols were used for enumerating MABS, and these quantified the effectiveness of UV-C doses (in triplicate). UV-C effectiveness was estimated using the difference between inactivation with and without UV-C. FINDINGS Sixteen tests were performed, with UV-C doses ranging from 276 to 1104 μW s/cm2. Mean (±SD) UV-C effectiveness ranged from 47.1% (±13.4) to 83.6% (±3.3). UV-C led to significantly greater inactivation of MABS (all P-values ≤0.045) than natural decay at all doses assessed. Using an indoor model of the hospital environment, it was estimated that UV-C doses in the range studied here could be safely delivered in clinical settings where patients and staff are present. CONCLUSION This study provides empirical in-vitro evidence that nebulized MABS are susceptible to UV-C inactivation.
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Affiliation(s)
- T T Nguyen
- Faculty of Medicine, School of Public Health, University of Queensland, Brisbane, QLD, Australia.
| | - C He
- International Laboratory for Air Quality & Health, School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - R Carter
- Centre for Children's Health Research, Brisbane, QLD, Australia
| | - E L Ballard
- QIMR Berghofer Institute of Medical Research, Brisbane, QLD 4006, Australia
| | - K Smith
- Centre for Children's Health Research, Brisbane, QLD, Australia
| | - R Groth
- International Laboratory for Air Quality & Health, School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - E Jaatinen
- School of Chemistry and Physics, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - T J Kidd
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia; Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - R M Thomson
- The Prince Charles Hospital, Brisbane, QLD, Australia; Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia; Gallipoli Medical Research Foundation, Greenslopes Private Hospital, Brisbane, QLD, Australia
| | - G Tay
- The Prince Charles Hospital, Brisbane, QLD, Australia
| | - G R Johnson
- International Laboratory for Air Quality & Health, School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - S C Bell
- Centre for Children's Health Research, Brisbane, QLD, Australia; The Prince Charles Hospital, Brisbane, QLD, Australia; Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia; Translational Research Institute, Brisbane, QLD, Australia
| | - L D Knibbs
- Public Health Unit, Sydney Local Health District, Camperdown, NSW, Australia; Faculty of Medicine and Health, School of Public Health, University of Sydney, NSW, Australia
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Stockwell RE, Ballard EL, O'Rourke P, Knibbs LD, Morawska L, Bell SC. Indoor hospital air and the impact of ventilation on bioaerosols: a systematic review. J Hosp Infect 2019; 103:175-184. [PMID: 31279762 DOI: 10.1016/j.jhin.2019.06.016] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/28/2019] [Indexed: 10/26/2022]
Abstract
Healthcare-acquired infections (HAIs) continue to persist in hospitals, despite the use of increasingly strict infection-control precautions. Opportunistic airborne transmission of potentially pathogenic bioaerosols may be one possible reason for this persistence. Therefore, this study aimed to systematically review the concentrations and compositions of indoor bioaerosols in different areas within hospitals and the effects of different ventilation systems. Electronic databases (Medline and Web of Science) were searched to identify articles of interest. The search was restricted to articles published from 2000 to 2017 in English. Aggregate data was used to examine the differences in mean colony forming units per cubic metre (cfu/m3) between different hospital areas and ventilation types. A total of 36 journal articles met the eligibility criteria. The mean total bioaerosol concentrations in the different areas of the hospitals were highest in the inpatient facilities (77 cfu/m3, 95% confidence interval (CI): 55-108) compared with the restricted (13cfu/m3, 95% CI: 10-15) and public areas (14 cfu/m3, 95% CI: 10-19). Hospital areas with natural ventilation had the highest total bioaerosol concentrations (201 cfu/m3, 95% CI: 135-300) compared with areas using conventional mechanical ventilation systems (20 cfu/m3, 95% CI: 16-24). Hospital areas using sophisticated mechanical ventilation systems (such as increased air changes per hour, directional flow and filtration systems) had the lowest total bioaerosol concentrations (9 cfu/m3, 95% CI: 7-13). Operating sophisticated mechanical ventilation systems in hospitals contributes to improved indoor air quality within hospitals, which assists in reducing the risk of airborne transmission of HAIs.
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Affiliation(s)
- R E Stockwell
- Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia; Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - E L Ballard
- Statistical Support Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - P O'Rourke
- Statistical Support Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - L D Knibbs
- School of Public Health, The University of Queensland, Herston, Queensland, Australia
| | - L Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - S C Bell
- Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia; Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia; Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Chermside, Queensland, Australia.
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Ballard EL, Dietzgen RG, Sly LI, Gouk C, Horlock C, Fegan M. Development of a Bio-PCR Protocol for the Detection of Xanthomonas arboricola pv. pruni. Plant Dis 2011; 95:1109-1115. [PMID: 30732059 DOI: 10.1094/pdis-09-10-0650] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A real-time SYBR Green I assay was developed and evaluated as a biological and enzymatic polymerase chain reaction (Bio-PCR) protocol for the detection of Xanthomonas arboricola pv. pruni. Suppression subtractive hybridization was used to generate a X. arboricola pv. pruni-specific subtracted DNA library, using X. arboricola pv. corylina as the driver strain. Primer pair 29F/R, designed from cloned sequence, showed no homology to GenBank sequences and amplified a 344-bp product in all X. arboricola pv. pruni isolates. Compared with other published X. arboricola pv. pruni primers, this primer pair was shown to be the only one capable of differentiating X. arboricola pv. pruni from all other X. arboricola pathovars. A real-time assay was developed and shown to be capable of detecting less than 10 CFU and 0.1 pg of DNA. Epiphytic bacteria isolated from plum tissue was used to further evaluate the specificity of the assay. A Bio-PCR protocol, developed for field evaluation, confirmed X. arboricola pv. pruni isolation from asymptomatic and symptomatic plum tissue over a 9-week period between host flowering and the first appearance of leaf and fruit symptoms in an orchard. Dilution plating enabled X. arboricola pv. pruni numbers to be quantified, providing supportive evidence for the usefulness of the Bio-PCR protocol in plant pathology and quarantine surveillance.
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Affiliation(s)
- E L Ballard
- School of Chemistry and Molecular Biosciences, The University of Queensland, Australia
| | - R G Dietzgen
- School of Chemistry and Molecular Biosciences, The University of Queensland, and Department of Employment, Economic Development and Innovation Agri-Science Queensland, Australia
| | - L I Sly
- School of Chemistry and Molecular Biosciences, The University of Queensland
| | - C Gouk
- Department of Primary Industries, Victoria, Australia
| | - C Horlock
- Department of Employment, Economic Development and Innovation, Agri-Science Queensland
| | - M Fegan
- School of Chemistry and Molecular Biosciences, The University of Queensland
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Ballard EL. Social work perspectives: issues in caregiver research: the family. Alzheimer Dis Assoc Disord 1999; 13 Suppl 1:S88-92. [PMID: 10369526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
More than 4 million persons in the United States are believed to have Alzheimer disease. Seven of 10 are cared for in the community by family members who make numerous decisions ranging from those that have to do with personal care and daily activities to participation in research. Families who do participate in research or who agree for the dementia-impaired individual to participate, do so for a variety or reasons, including the altruistic reason of finding a cure or treatment that may help others. This paper looks at the caregiving experience and those issues that may influence the family to participate in research, what families expect from research, and how they expect researchers to treat the impaired relative.
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Affiliation(s)
- E L Ballard
- Duke Family Support Program, Duke University Medical Center, Durham, North Carolina 27710, USA
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Abstract
Nine Consortium to Establish a Registry for Alzheimer's Disease (CERAD) sites were surveyed to identify barriers to recruiting black subjects. Major cited obstacles were expenses, transportation difficulties, and especially lack of rapport with clinic staff. Major factors in overcoming these barriers are a good referral network involving the black community, community education about Alzheimer's disease (AD), and professional staff who are particularly sensitive to the needs of the black population. CERAD efforts to increase community awareness of Alzheimer's disease and staff sensitivity to minority needs have nearly doubled the proportion of black subjects enrolled.
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Affiliation(s)
- E L Ballard
- Department of Psychiatry, Duke University Medical Center, Durham, NC
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