We investigated several sterilisation techniques to employ within the process of cleaning hypodermic needles and medical instruments. Our investigation considered the suitability, availability and the cost of each method to select the most eligible one for a small health facility in a remote area.
Needles, syringes and surgical instruments should be submerged in a disinfectant before cleaning. Disinfectants are in fact required to deactivate pathogens. Reusable needles have to be handled with great care: they have to be disinfected in special containers and then cleaned to remove debris and finally sterilized. These operations should be made when wearing thick gloves. The purpose of disinfection is to reduce the risk while handling the material for cleaning. There are many disinfectants each one with different effectiveness, the most widely available being a solution of sodium hypochlorite.
Sterilisation and cleaning are complementary procedures: after cleaning the material with ultrasonic wave is in fact not yet sterilised, whilst the sterilization does not remove debris. The sterilization process aims to destroy all forms of microbial life, including spores, by either physical or chemical actions.
Health facilities sterilise their equipment using different methods. The International Organization for Standardization (“ISO”) stipulates several regulations and suggests best practices for the sterilisation of medical devices, in order to ensure safety of the staff and of the patients. The ISO 14937 provides the general framework to characterise a sterilising agent and to develop a sterilisation process [22].
Some rudimental methods, such as boiling and flaming, are still in use. However, neither of them is considered an exhaustive sterilization technique, since it does not effectively remove all microorganisms. Therefore, boiling has to be considered an unsafe practice. To select the “best” sterilization method, considering the specific rural context we have selected, it is necessary to identify the materials that compose the object to be sterilized, and also consider the amount and kind of microorganisms to be removed.
According to Appendix A, Table 2, we can see that 70% ethanol is the best solution to use for sterilisation. It can kill a wide range of bacteria and the most common virus in Africa—HIV. Compared to other sanitisation methods and reagents, the ethyl ethanol has the lowest cost and highest efficiency of sterilization. Also, the disinfecting operation is the most convenient and safe, which is just dipping needles to the alcohol for 20 minutes. What’s more, the lowest cost of production is very suitable for rural and underdeveloped areas in Africa.
Interestingly, although ethanol works mostly by dehydrating the bacteria, 100% or 95% of ethanol don't sterilise nearly as quickly or as effective as 70% ethanol. A few seconds exposure is adequate: As little as 30 seconds will give results essentially as good as days of immersion. 100% ethanol is uncommon outside of laboratories, because ethanol will absorb water out of the air [13].
Ethanol is made by fermenting sugars found in grains into ethyl alcohol which is an organic solvent. It is biodegradable without harmful effects to the environment [14]. However, disposal of ethanol waste near a heated or ignition source can cause fire. Therefore, great care must be taken in their disposal.