Hand hygiene is a primary public health topic, leading many people to rely on portable products like hand sanitizer to protect against common infections. A frequent concern is whether these products are effective against specific pathogens, such as the bacteria that cause strep throat. Understanding the capabilities and limitations of hand sanitizer requires looking closely at the science behind both the microbe and the product.
What is Streptococcus and How is it Transmitted?
Streptococcus is a genus of bacteria responsible for a wide range of illnesses, most notably Group A Streptococcus (GAS), which causes strep throat and scarlet fever. These bacteria typically colonize the nose and throat and are highly contagious. They spread primarily through respiratory droplets released when an infected person coughs or sneezes, which can be breathed in by others.
Transmission also occurs through direct contact with contaminated surfaces or hands. If a person touches a contaminated surface and then touches their own mouth or nose, they can transfer the bacteria, leading to infection. This contact route highlights why good hand hygiene is recommended to interrupt the spread of streptococcal infections.
The Mechanism of Hand Sanitizer
Hand sanitizers are divided into two main categories: alcohol-based and non-alcohol-based products. Alcohol-based sanitizers typically use ethanol or isopropanol as their primary germ-killing agent, working by denaturing the essential proteins within the microbial cell and disrupting its structure.
The alcohol also dissolves the outer lipid layer of the microbe, causing cell damage and immediate destruction. This rapid destruction makes alcohol highly effective against a broad spectrum of bacteria and viruses. Non-alcohol sanitizers often rely on compounds like benzalkonium chloride, which disrupt the cell wall, though their effectiveness can be more variable.
Direct Efficacy Against Strep Bacteria
Streptococcus is a Gram-positive bacterium, and this type of organism is highly susceptible to the effects of alcohol-based hand sanitizers. Alcohol-based hand rubs are effective against a wide range of bacteria, including those that lack protective structures like spores.
For a hand sanitizer to be reliably effective against Streptococcus and other germs, the Centers for Disease Control and Prevention (CDC) recommends a minimum alcohol concentration of 60%. Formulations containing between 60% and 95% alcohol are the most potent at rapidly killing microbes. Lower alcohol concentrations or non-alcohol-based sanitizers may only reduce bacterial growth rather than killing them outright, making their efficacy against strep unreliable.
Comprehensive Hygiene Practices for Strep Prevention
While alcohol-based hand sanitizer is effective at inactivating Streptococcus bacteria, it is considered a secondary hygiene measure when soap and water are not available. Handwashing remains the gold standard because it physically removes all types of germs, dirt, and organic matter from the hands, rather than just killing them in place. This physical removal is particularly important if the hands are visibly dirty or greasy, as heavy soiling reduces the effectiveness of hand sanitizer.
The proper technique for handwashing involves scrubbing the hands with soap and running water for at least 20 seconds, ensuring all surfaces are covered. When using hand sanitizer, apply a sufficient amount to cover all surfaces of both hands and rub them together until they are completely dry. Practicing hand hygiene is especially important after coughing or sneezing, before eating or preparing food, and after being in public places.