What factor primarily contributes to the risk of MRSA transmission?

The primary factor that contributes to the risk of MRSA (Methicillin-resistant Staphylococcus aureus) transmission is indeed the practice of not washing hands. Hand hygiene is crucial in preventing the spread of infections, including MRSA. When individuals fail to wash their hands, they may inadvertently transfer bacteria from contaminated surfaces or their own skin to their own bodies or to other people. This is particularly significant in healthcare settings or crowded living environments where many people may be in close contact with each other.

Maintaining proper hand hygiene practices significantly reduces the potential for MRSA to spread, as handwashing removes pathogens that can cause infection. In contrast, while factors like public swimming pools, antibiotics misuse, and contact sports may be associated with MRSA transmission risks, they are not as directly related to everyday actions that individuals can control, such as handwashing. Hence, the importance of hand hygiene stands out as a fundamental preventive measure against MRSA transmission.