Disinfectant Evaluation in Healthcare Facilities

The Challenge

The hospital environment allows for the growth and survival of nosocomial pathogens. Nosocomial pathogens, Clostridium difficile and Methicillin-resistant Staphylococcus aureus, can be isolated on up to 58% of hospital surfaces. Cleaning and disinfecting the surfaces significantly disrupts the ecological niches of the pathogens (Dancer, 1999).

Many traditional chemical disinfectants have drawbacks. These include potential reactivity with acids and other chemicals that produce toxic fumes, irritation to skin, eyes and respiratory tract as well as corrosion of the surfaces (Sexton, 2011). Hydrogen peroxide is a well-known disinfectant, with minimal drawbacks. It has even been shown to deactivate Cryptosporidium parvum within 20 minutes (Anderson, 2005). Liquid disinfection with hydrogen peroxide could help to alleviate many of the problems that are associated with commonly used traditional chemical disinfectants in the hospital environment.

Disinfectants are tested in the laboratory setting but results can vary under real world conditions. In this study a hydrogen peroxide based disinfectant was tested in the hospital setting to determine efficacy and potential benefits and drawbacks of the product for SpectraShield, a local company.


  1. Quantitate the efficacy of SpectraKillTM against viruses in a hospital/out-patient setting using viral tracers.
  2. Quantitate the efficacy of SpectraKillTM against indigenous Staphylococcal species in a hospital/out-patient setting.
  3. Quantitate the efficacy of SpectraKillTM against bacterial spores in a hospital/out-patient setting using Bacillus thuringiensis spores.

How We Helped

The research team involved two microbiologists, who specialize in environmental contamination and pathogen control. The diverse nature of this project, laboratory and field based methods as well as differing methods in detection of the three different types of organisms made this a perfect project for training of undergraduate researchers. The research team consisted of one undergraduate researcher who aided in the competition of the microbial assays.

Two local hospitals were recruited to participate in this study. Healthcare workers helped to identify high touch surfaces that can be difficult to clean using traditional disinfectants. Select surfaces were then sampled and assayed for the presence of Staphylococcal species. Surfaces were also seeded with bacteriophage Phi X174, Staphylococcus aureus, and Bacillus thuringiensis spores. Surfaces were sampled before and after application of the disinfectant. Samples were assayed at the ESRAC laboratory and results were analyzed to determine the efficacy of the product. In addition, feedback from the participating hospitals was delivered to the client.


The hydrogen peroxide based disinfectant was effective at reducing >4 logs of surrogate pathogens in both the laboratory and the hospital environment. Samples were below the limit of detection suggesting that the disinfectant is able to achieve even greater pathogen reductions.

Results from this study were presented to the client in the form of an interim and a final report. The final report has also been given to the participating hospitals and thus opening up a dialogue between the hospitals and the client. The study has also been submitted to various healthcare related conferences for poster presentations and is also being written up for publication into a scientific peer reviewed journal.


  • Andersen BM, Rasch M, Hochlin K, Jensen F-, Wismar P, Fredriksen J-. Decontamination of rooms, medical equipment and ambulances using an aerosol of hydrogen peroxide disinfectant. J Hosp Infect. 2006 2;62(2):149-55.
  • Dancer SJ. Mopping up hospital infection. J Hosp Infect. 1999 10;43(2):85-100.
  • Sexton J, Tanner B, Maxwell S, Gerba C. Reduction in the microbial load on high-touch surfaces in hospital rooms by treatment with a portable saturated steam vapor disinfection system. Am J Infect Control. 2011 10;39(8):655-62.