Today, there's higher awareness that hands play a major role in transmission of infectious germs. This has led to greater emphasis on 'clean hands', especially in the areas of food processing, catering & healthcare; and naturally, its importance is heightened in infection control and epidemic management.
Even hands that appear clean (without visible dirt) may still harbour deadly germs. For effective hand disinfection, one needs to discern and choose the best method available.
Water-based Hand Disinfectants
The simplest method of hand disinfection is to wash hands with water or soap and water. This is often reasonably effective, provided only clean, microbe-free water is used; but generally water of such quality is rare. And even if one uses medicated soap for washing hands, there is a high possibility of re-infection by use of unclean water.
There are water-based chemical formulations that are manufactured using microbe-free water. Some of them have phenolic compounds such as chloro-xylinol as the chief antiseptic ingredient. These products are used after dilution with water. They may be suitable for sanitisation of rooms, use in bathwater, aftershave rinse, etc. but for wound irrigation and cleaning of cuts, they should be diluted with sterilised (for example, boiled and cooled) water.
Chloro-xylinol has the limitation of low antimicrobial activity. It is known to be less active against gram negative bacteria, among which are some deadly pathogen varieties and many moulds. The chemical's effectiveness against viruses has not been examined adequately. It is also known to be easily inactivated by water hardness and non-ionic detergents.
Alcohol-based Hand Disinfectants
Alcohol-based disinfectants act rapidly and thoroughly. They also evaporate fast, leaving no residue. Most alcohol-based disinfectants contain isopropanol, n-propanol, ethanol or their combinations. The germicidal property is manifest when alcohol content is 60% to 90%.
Alcohols are reported to have excellent germicidal activity against gram positive and gram negative vegetative bacteria, including multi-drug resistant pathogens (e.g. MRSA, VRE) and mycobacterium tuberculosis. Their germicidal effect against lipid enveloped viruses (influenza viruses, HIV, herpes simplex virus, vaccinia virus) has been well established. Though alcohols are not sporicidal, they prevent germination of spores.
Advantages of Alcohol-based Formulations
- They kill viruses and bacteria almost instantaneously on contact. Their germicidal property is based on the de-naturation of cell-surface proteins that are involved in the infective process and pathogenesis (e.g.H1N1 virus) & on disruption of cell membrane integrity of microbes.
- After using the disinfectant, there is no need for washing of hands with water. Also. some preparations may also have a long acting chemical such as quaternary ammonium salt, which ensures prolonged protection against re-infection.
- They are also suitable for disinfection of rooms through fogging.
Alcohol-based formulations are a better option for disinfection of hands when compared to water-based formulations. Even though the latter is more convenient for everyday use, and simple, alcohol-based disinfectants ensure complete disinfection, which makes them ideal for a range of disinfection purposes.