Spead of microbes

Sifuentes, L.Y. et al. 2016. Use of ATP Readings to Predict a Successful Hygiene Intervention in the Workplace to Reduce the Spread of Viruses on Fomites.

Objective

Research how viruses spread in an office environment (80 full-time employees)

• from hand to surface
• from one surface to another, and
• whether ATP measurement results and virus levels measured from surfaces correlate.

Test were made before and after instructing staff in hygiene practices.
• As a hygiene practice: handcuffs, face wipes and surface disinfectant wipes were provided, and their correct use and use were instructed.

Methods

• MS-2 bacteriophage used, 6 × 109 / cm2
• It was placed to a handle after the lift lobby (50 cm2) before staff arrive and to one volunteer’s hand.
• Surfaces (54 different surfaces) and hands of other subjects (42 persons) were tested after 4 and 7 hours of soiling.
• The surfaces were table and countertops, the handles of the refrigerator, the microwave oven and the coffee pot, the buttons of the vending machine.

Results and conclusions

Inoculation of one employee’s hand:

• Without hygiene instruction:
  • After 4 hours, bacteriophage was found in 56 % of the surfaces examined, after 7 hours in 63 %.
• After hygiene instruction
  • Amounts: after 4 hours 9 %, after 7 hours 30 %
  Inoculation of door handle:
• After hygiene instruction, there was 70 % fewer fomites contaminated after 4 h.
• There was no direct correlation between the results of ATP measurements and the results of surface virus measurements, but both measurement methods showed lower readings after guidance on hygiene practices.
• Conclusion: Although ATP measurement does not measure the number of viruses, the method is suitable for situations where the effect of different procedures, such as changes in hygiene practices, is tested.