Impetigo is a common skin infection that primarily affects infants and young children, though it can occur at any age. This condition is known for its highly contagious nature, making it a frequent concern in environments where close contact is common, such as schools and daycares. Understanding how impetigo spreads is important for preventing its transmission.
Understanding Impetigo
Impetigo manifests as red sores that quickly rupture, ooze, and then form a yellowish-brown crust. These sores can appear anywhere on the body, but they frequently develop around the nose and mouth, or on the arms and legs. The infection is primarily caused by two types of bacteria: Staphylococcus aureus and, less commonly, Streptococcus pyogenes. These bacteria are typically present on the skin and can cause infection when there is a break in the skin barrier, such as from a cut, scrape, or insect bite.
How Impetigo Bacteria Survive on Surfaces
The bacteria responsible for impetigo, specifically Staphylococcus aureus and Streptococcus pyogenes, can survive on inanimate surfaces outside the human body. These surfaces, often referred to as fomites, can include clothing, towels, toys, and other household items. The viability of these bacteria on surfaces is influenced by several environmental factors, including the type of surface material, the surrounding temperature, and the level of humidity.
Staphylococcus aureus can persist on various dry surfaces for extended periods, ranging from days to even weeks. It has been found to survive on plastic, fabric, and other common materials for several days. Streptococcus pyogenes, while generally less hardy than Staphylococcus aureus, can also remain viable on surfaces for hours to days. Its survival time is sensitive to desiccation, faring better in humid conditions.
Non-porous surfaces like plastic and metal generally allow for longer bacterial survival compared to porous materials such as fabric or paper. Higher temperatures and lower humidity tend to reduce the survival time of these bacteria, while cooler, more humid environments can extend it. While these bacteria do not actively multiply on surfaces, their ability to remain viable for a significant duration means that contaminated items can serve as a source of transmission, highlighting the importance of environmental hygiene.
Cleaning and Hygiene to Prevent Spread
Preventing the spread of impetigo involves diligent cleaning practices and consistent personal hygiene. Regularly cleaning frequently touched surfaces can significantly reduce the presence of impetigo-causing bacteria. Household disinfectants, including those containing diluted bleach solutions or alcohol, are effective at eliminating these bacteria from hard surfaces like doorknobs, countertops, and light switches. Following the product instructions for contact time is important to ensure proper disinfection.
Laundry practices are also important for items that may have come into contact with infected skin. Clothing, towels, and bed linens used by someone with impetigo should be washed separately in hot water with detergent. Drying these items on a hot cycle can further help in killing any remaining bacteria. Toys and other washable items should also be cleaned and disinfected regularly, especially if shared among children.
Handwashing is one of the most effective personal hygiene measures to prevent the transmission of impetigo. Individuals with the infection, as well as their caregivers, should wash their hands frequently with soap and water for at least 20 seconds. This practice is particularly important after touching the infected areas or before preparing food. Keeping fingernails short and clean can also reduce the likelihood of bacteria harboring under the nails and spreading.