It may seem counterintuitive, but various studies suggest that a handshake can transfer more germs than a kiss. This concept sheds light on the intricate dynamics of human interactions and the transmission of microbes. Hands are the primary instruments we use to interact with our environment. They touch everything from door handles and smartphones to money and other hands. Each surface potentially harbors a multitude of germs including bacteria and viruses, making hands a significant vessel for germs.
In contrast, the mouth has its mechanisms for reducing microbial loads. Saliva contains enzymes that destroy bacteria and neutralize viruses, making the mouth a somewhat less hospitable environment for germs than the skin on hands. Moreover, most people maintain oral hygiene practices like brushing teeth and using mouthwash, which further reduce the microbial load in the mouth. Of course, the types of microbes present in the mouth and on the skin differ widely, so the potential for disease transmission via a kiss versus a handshake varies depending on the specific microbes present.
The spread of illnesses such as colds and flu are often attributed more frequently to hand-to-hand contact rather than to direct mouth-to-mouth contact. This is because respiratory viruses are easily transferred on the hands and can survive there long enough to get passed from one person to another. When someone with a cold touches their nose or mouth and then shakes another person's hand, those germs can be passed directly. If the recipient then touches their face, the germs get a direct pathway to new host cells.
In public health contexts, particularly in flu seasons or during outbreaks like the COVID-19 pandemic, health experts often encourage alternatives to handshaking such as waving, nodding, or other hands-free greetings. This has been shown to help minimize the transmission of pathogens. Similarly, social norms and public awareness campaigns can also adjust to reduce risks, highlighting the importance of regular and thorough hand washing with soap and water to destroy potential pathogens transferred during handshakes.
Therefore, while a kiss might seem more intimate and likely to spread germs, the fact that our hands touch many more potentially contaminated surfaces and the reduced microbial defense capabilities of skin compared to oral tissues, make handshakes a potentially more significant means of germ transmission. Both practices, however, carry their risks and understanding these can lead to better hygiene practices and reduced transmission of diseases.
