The residual effectiveness of chlorhexidine gluconate 0.5% on vaccinating nurses hands during school vaccination programmes : a pilot study : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Nursing at Massey University (Auckland), New Zealand
In the well-health community setting of school based student mass vaccination programmes (MVPs) the risks of cross-infection are not clear, as hand cleansing is not always practised between each injection administered by public health nurses (PUNs). This study provides evidence of the microbial colony forming units (CFUs) gathered from Auckland District Health Board's PHNs hand flora (finger-tip press on agar plates) during MVPs. The purpose of the study was to describe the antimicrobial residual efficacy over time of chlorhexidine gluconate 0.5%, a component of the alcohol-based hand gel (Sterigel+) used as a hand hygiene product at MVPs by PHNs. A non-experimental survey (pilot) design gathered vaccinators' palmar finger-tip skin flora prior to hand cleansing. Sampling was conducted over an eight week period at 17 schools settings from participating vaccinators at each programme. Hand flora were collected on 77 occasions (N = 154 agar plate samples), from dominant and non-dominant hands and the CFUs reported by LabPlus. No indications were found of a threshold to signify that chlorhexidine gluconate 0.5% was active up until a specific time and CFUs increased over the whole timeframe (5-90 minutes). A weak but significant correlation was found between the total CFUs and timeframe (r = 0.272, p = 0.001). Sixteen flora types were grown and formed into four microbial categories: skin flora (85% of all CFUs), Gram-negative flora (7%), environmental organisms (6%) and oral flora (2%). Potentially pathogenic flora were grown (Staphylococcus aureus occurring on 5% of samples and Gram-negative bacteria 17.5%). However, relatively few samples of highly pathogenic micro-organisms were culture positive and low CFU counts were identified. It was considered that, for healthy individuals, the cross infection risks presented were minimal. The vaccinators reasons to cleanse hands was strongly significant (p = 0.018) with non-convenience CFUs being on average 88% higher than convenience CFUs at any particular time point. Hand dominance was shown not to be significant. The results of this study indicate that Sterigel+ does not provide ongoing antimicrobial protection beyond the quantified effects of an alcohol-based hand gel. Therefore, PHNs need to take this information into account when considering hand hygiene practice decisions related to cross infection risks during MVPs.