Bacterial pink eye, also known as bacterial conjunctivitis, is a common and highly contagious infection that causes inflammation of the conjunctiva, the clear membrane covering the white part of the eye and the inside of the eyelids. This inflammation leads to the characteristic redness or “pinkness” of the eye. Understanding how the bacteria responsible for this infection can persist on surfaces is important for preventing its spread.
Survival on Surfaces
The bacteria that cause pink eye can remain viable on inanimate surfaces for a period of time, posing a risk of transmission. Generally, bacterial conjunctivitis pathogens may survive on surfaces for 24 to 48 hours, though some strains may persist for longer or shorter periods. This longevity means that objects frequently touched by an infected individual can harbor the bacteria, potentially spreading the infection to others who come into contact with them.
The duration of survival can vary depending on the specific bacterial strain and the environmental conditions present on the surface, such as temperature, humidity, and the type of material.
Elements Affecting Survival
Several environmental and surface-specific factors influence how long bacteria causing pink eye can survive outside the human body. Temperature plays a role, with cooler temperatures generally prolonging the survival of these pathogens. In contrast, higher temperatures can accelerate their degradation.
Humidity is another significant factor; high humidity levels can help bacteria survive for longer periods on surfaces. The type of surface material also directly impacts bacterial longevity. Non-porous surfaces, like metal, glass, or plastic, do not absorb moisture and are less reactive, creating a more favorable environment for bacteria to remain viable for extended durations.
Porous surfaces, such as fabrics, paper, or cardboard, absorb moisture, which can dehydrate and weaken the bacteria more quickly, leading to a shorter survival time. Smooth surfaces, like plastic, may also allow pathogens to persist longer compared to rougher surfaces like fabric.
Reducing Transmission and Cleaning Surfaces
Preventing the spread of bacterial pink eye involves diligent surface hygiene and personal practices. Frequent handwashing with soap and water for at least 20 seconds is a primary defense, especially after touching an infected person or items they have used. If soap and water are not available, an alcohol-based hand sanitizer containing at least 60% alcohol can be used.
Cleaning and disinfecting surfaces, especially high-touch areas, are also important steps. Disinfectants containing at least 70% alcohol or bleach-based cleaning solutions are effective at killing pink eye pathogens on most surfaces. For example, a bleach solution of 2,000–5,000 parts per million (ppm) chlorine, equivalent to 10 to 25 tablespoons of bleach per gallon of water, can be used. It is important to ensure disinfectants remain on surfaces for the recommended contact time, often applied wet and allowed to air dry.
Personal items such as pillowcases, sheets, washcloths, and towels should be washed often in hot water with detergent. It is also recommended to avoid sharing personal items like eye drops, eye or face makeup, makeup brushes, contact lenses, contact lens cases, or eyeglasses, as these can easily become contaminated. Additionally, individuals with pink eye should avoid touching or rubbing their eyes to prevent spreading the infection to their other eye or to surfaces.