Understanding MRSA
Methicillin-resistant Staphylococcus aureus, commonly known as MRSA, is a type of staph infection that has developed resistance to several common antibiotics, including methicillin, amoxicillin, and penicillin. This resistance makes MRSA infections more challenging to treat. Understanding how MRSA survives outside the human body, particularly on surfaces, is important for preventing its spread in various environments.
Understanding MRSA’s Resilience
MRSA’s capacity to survive on surfaces stems from its microbial characteristics and environmental conditions. Staphylococcus aureus bacteria are robust, with cell walls that protect against desiccation, allowing them to endure dryness outside a host.
Various environmental factors influence MRSA’s viability on surfaces. Cooler temperatures favor longer survival by slowing down bacterial metabolic processes and degradation. Higher humidity can extend survival by reducing the rate of drying.
The presence of organic material, such as skin cells, dust, or bodily fluids like mucus or dried blood, can offer a protective matrix for MRSA. These materials can shield the bacteria from environmental stressors and provide nutrients, thereby prolonging their viability. The type of surface material itself also impacts survival, as some materials offer more hospitable environments than others.
How Long MRSA Persists on Common Surfaces
MRSA can persist on common surfaces for days to several weeks, depending on the material and environmental conditions. On non-porous surfaces, such as plastic, stainless steel, or glass, MRSA remains viable for days. Studies have shown it can survive for up to 7 days on plastic and metal surfaces. This includes doorknobs, medical equipment, and countertops.
The persistence of MRSA on porous materials, such as fabrics, clothing, and towels, is notable. It survives on these surfaces for several days, sometimes weeks. For instance, MRSA can live on cotton for 1 to 3 weeks. This highlights transmission through contaminated linens, uniforms, or shared personal items.
Human skin can also harbor MRSA, known as transient colonization. While handwashing can remove these bacteria, MRSA can survive on hands for several hours if not properly washed away. The presence of MRSA on skin can lead to self-inoculation or transmission to surfaces or other individuals through direct contact.
Reducing Surface Contamination and Transmission
Implementing consistent cleaning and disinfection protocols is a primary strategy for reducing MRSA contamination on surfaces. Regular cleaning of frequently touched surfaces with appropriate detergents helps remove organic matter and reduce bacterial load. Following cleaning, disinfection with EPA-registered disinfectants effective against Staphylococcus aureus is crucial.
For non-porous surfaces, commercially available disinfectants or a diluted bleach solution (e.g., 1 part bleach to 10 parts water) are effective when used according to manufacturer instructions. Ensuring adequate contact time for the disinfectant is important for its efficacy. In healthcare settings, specific guidelines are followed for environmental cleaning to minimize pathogen spread.
Personal hygiene measures, particularly frequent and thorough handwashing, is important in preventing MRSA transmission. Washing hands with soap and water for at least 20 seconds, especially after touching contaminated surfaces, using the restroom, or before eating, helps remove transient MRSA. When soap and water are unavailable, an alcohol-based hand sanitizer with at least 60% alcohol can be used.
Regular laundering of clothing, towels, and other fabric items in hot water with detergent can also help reduce MRSA contamination. These practices, when combined, create a layered approach to minimize the survival and spread of MRSA from environmental surfaces.