Publications by authors named "Laura Y Sifuentes"

The purpose of this study was to validate the use of adenosine triphosphate (ATP) for evaluating hygiene intervention effectiveness in reducing viral dissemination in an office environment. The bacterial virus MS-2 was used to evaluate two scenarios, one where the hand of an individual was contaminated and another where a fomite was contaminated. MS-2 was selected as a model because its shape and size are similar to many human pathogenic viruses.

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Fabrics, such as clothing, drapes, pillowcases, and bedsheets are potential sources of pathogenic bacteria and viruses. We found fabrics (ie, professional clothing, pillowcases, and lab coats) treated with a silver-impregnated material to be effective in significantly reducing a wide spectrum of ordinary and drug-resistant microorganisms, including Salmonella, methicillin-resistant Staphylococcus aureus, Propionibacterium acnes, Trichphyton mentagrophytes, and norovirus. Fabrics impregnated with antimicrobial agents help provide an additional barrier to the transport or reservoir of pathogens in health care environments.

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Viral illnesses such as gastroenteritis and the common cold create a substantial burden in the workplace due to reduced productivity, increased absenteeism, and increased health care costs. Behaviors in the workplace contribute to the spread of human viruses via direct contact between hands, contaminated surfaces, and the mouth, eyes, and/or nose. This study assessed whether implementation of the Healthy Workplace Project (HWP) (providing hand sanitizers, disinfecting wipes, facial tissues, and use instructions) would reduce viral loads in an office setting of approximately 80 employees after seeding fomites and the hands of volunteer participants with an MS-2 phage tracer.

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Article Synopsis
  • About 50% of norovirus cases in the U.S. occur in long-term care facilities; the study aimed to track viral movement and assess hygiene measures against transmission.
  • MS-2 coliphage was applied to a staff member's hands, and after sampling over three days, a 14-day hygiene intervention using disinfectants and sanitizers was implemented.
  • Results showed significant reductions in MS-2 levels on hands and surfaces (over 99% decrease), indicating that hygiene interventions effectively cut down viral spread in the facility.
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Although the number of illnesses resulting from indirect viral pathogen transmission could be substantial, it is difficult to estimate the relative risks because of the wide variation and uncertainty in human behavior, variable viral concentrations on fomites, and other exposure factors. The purpose of this study was to evaluate the micro-activity approach for assessment of microbial risk by adapting a mathematical model to estimate probability of viral infection from indirect transmission. To evaluate the model, measurements of phage loading on fomites and hands collected before and after implementation of a Healthy Workplace Project intervention were used.

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The goals of this study were to observe the spread of viruses in a hotel setting and to assess the effectiveness of a hygiene intervention in reducing their spread. Selected fomites in one hotel room were inoculated with bacteriophage ϕx-174, and fomites in a conference center within the same hotel were inoculated using bacteriophage MS2. Cleaning of the contaminated room resulted in the spread of viruses to other rooms by the housekeeping staff.

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Naegleria fowleri is a free-living amoeba found in waters in warmer regions that causes primary amoebic meningoencephalitis, a rare but almost universally fatal disease. The goal of this project was to assess the occurrence of N. fowleri and other thermophilic amoebae in 33 recreational surface waters across Arizona to determine if their presence could be correlated with seasonal or other environmental factors.

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Household bleach is typically used as a disinfectant for water in times of emergencies and by those engaging in recreational activities such as camping or rafting. The Centers for Disease Control and Prevention recommend a concentration of free chlorine of 1 mg/L for 30 minutes, or about 0.75 mL (1/8 teaspoon) of household bleach per gallon of water.

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Background: Hospital cleaning practices are critical to the prevention of nosocomial infection transmission. To this end, cloth towels soaked in disinfectants are commonly used to clean and disinfect hospital surfaces. Cloth cleaning towels have been linked to an outbreak of Bacillus cereus and have been shown to reduce the effectiveness of commonly used quaternary ammonium disinfectants.

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Cell culture assays in various formats have been used to study the infectivity of Cryptosporidium spp. as well as to determine the infectivity of naturally occurring oocysts in water. Currently, cell culture assays for infectious Cryptosporidium spp.

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