Cleanliness vs. Hygiene: Understanding the Difference and Importance in Preventing the Spread of Diseases
The COVID-19 pandemic has brought the significance of cleanliness and hygiene to the forefront of our minds. However, many people still confuse these two terms, which can lead to inadequate practices in preventing the spread of diseases. Cleanliness refers to the physical appearance of a surface, focusing on removing visible dirt, waste, and stains. On the other hand, hygiene is driven by practices and measures taken to maintain health and prevent the spread of disease, even when a surface appears clean.
Research has shown that respiratory viruses, such as influenza and coronaviruses, can remain viable on surfaces for varying periods, ranging from a few hours to several days, depending on the type of surface and the particular virus. This highlights the importance of understanding that even if a surface appears clean, it may not meet the hygiene standard required to prevent the spread of diseases.
Common environmental pathogens can survive on various surfaces for extended periods. For example, Influenza virus can survive up to 2 days, Vancomycin-resistant Enterococcus (VRE) can persist up to 120 days, while Pseudomonas aeruginosa, a bacterium associated with hospital-acquired infections, can survive for an astonishing 480 days. Norovirus, a highly contagious pathogen, can remain viable on surfaces for up to 7 days. Klebsiella, another bacterium linked to healthcare-associated infections, can persist for an incredible 900 days. S. aureus, including the resistant variant MRSA, can survive up to 210 days.
Several factors that affect pathogens’ survival period on surfaces include:
Type of surface: Pathogens survive longer on plastic and stainless steel surfaces compared to copper surface. For example, SARS-CoV-2 can survive up to 72 hours on plastic, 48 hours on stainless steel, and only 4 hours on copper. Influenza A virus remains infective for up to 48 hours on stainless steel and up to 12 hours on porous surfaces like paper at 35-40% humidity.
Environmental conditions: Pathogens survive longer in lower temperatures and higher humidity. However, UV light exposure can shorten their lifespan.
Presence of organic matter: Organic matter may serve as a nutrient source and provides a moist environment that prevents the microorganisms from drying out, which is a major factor in their inactivation. It also acts as a physical barrier to protect them from UV light, temperature fluctuations and other environmental factors. Therefore, blood, mucus or other organic matter prolong the survival of microorganisms. For instance, Norovirus can survive up to 7 days on surfaces, but in the presence of fecal matter, it can remain infectious for up to 2 weeks. Salmonella can survive for up to 4 weeks on dry surfaces, but in the presence of food residues, it can persist for several months.
Initial concentration of the microorganism: Higher initial concentrations lengthen detectable survival periods.
To effectively combat the challenge posed by harmful invisible viruses, it is essential to adopt a science-based approach to visualize hygiene and cleanliness. By doing so, we can devise appropriate cleaning protocols that effectively reduce the spread of illness-causing bacteria and viruses, even when they are not visible to the naked eye.
References:
[1] Leung, N. H. L. (2021). Transmissibility and transmission of respiratory viruses. Nature Reviews Microbiology, 19, 1–18. https://doi.org/10.1038/s41579-021-00535-6
[2] Wißmann, J. E., Kirchhoff, L., Brüggemann, Y., Todt, D., Steinmann, J., & Steinmann, E. (2021). Persistence of pathogens on inanimate surfaces: A narrative review. Microorganisms, 9(2), 343. https://doi.org/10.3390/microorganisms9020343
