Do experts agree on skin disinfection before an injection?

Introduction

We exercise, take our vitamins, eat our vegetables, and, yes, take our injections we have to. And we dutifully disinfect the skin before an injection. Life is good. The conventional wisdom says disinfecting prevents germs from entering the injection hole. So it is a good thing. Right? Looking at the history of disinfection, we can observe many experts were not convinced a pre-injection disinfection is necessary or even helpful.

There are several studies indicating that pre-injection disinfection is not necessary30. These studies show that there is no difference in the number of incidents of post-injection infection regardless of a prior disinfection. Dann (1969) conducted possibly the most comprehensive research study on practice issues about the disinfection of skin before injection31. Injections were given to 5,000 people – comprising students, staff and their families – aged between four months and 66 years, over a six-year period, during which they were monitored for any signs of infection. Dann observed that disinfection is not important unless the skin was visibly soiled. In instances where the skin was not disinfected before injection, no single case of local or systemic infection was observed. Based on these results, he dispensed with routine skin disinfection and recommended that this practice be adopted universally. Koivisto and Felig (1978) have also shown that there is no increased risk of infection if the injection site is not disinfected33. They measured the effect of routine skin preparation on skin bacterial flora in 13 patients with type1 diabetes. The skin was cleansed using 70% isopropyl alcohol for five seconds on several sites including the arm, leg and abdomen. This was found to reduce the bacteria count by 82-91%. On alternate weeks, over a three to five-month period, the patients omitted skin preparation before injecting insulin. More than 1,700 insulin injections were given and no signs of local or systemic infection were observed. Koivisto and Felig (1978) concluded that, although cleansing the skin with alcohol reduces the bacterial count, it is not always necessary to prevent infection from developing at the site. A smaller study involved 93 patients being swabbed with alcohol before injection and 103 patients not being swabbed (Sutton et al 1999)35. Observations were carried out at one, three and five days following injection, during which time only two patients developed an infection in the form of an abscess. Both patients had been swabbed with alcohol but were on steroid therapy, which is known to suppress the immune system. The trial concluded that there was no significant difference between the two groups. Based on these and similar studies, the WHO (World Health Organization) advises that swabbing clean skin is unnecessary, although it states that visibly soiled or dirty skin should always be washed before injection. It considers that, although piercing the skin by injection can introduce bacteria from skin flora, most of these bacteria are non-pathogenic and the small number that might be introduced would be lower than the minimum infectious dose necessary for infection to occur (Hutin et al 2003)34.

At Painless World, we offer a device that significantly reduces injection pain, called Noodle. Noodle makes injections more comfortable and at the same time disinfects the skin before an injection with 70% rubbing alcohol. Even though there is plenty of evidence that disinfection is not needed, we still opt to follow the established norms and practices in the medical community. For more information about Noodle.