Nasal screening for Staphylococcus aureus--daily routine with improvement potentials

Abstract

Objectives: Staphylococcus aureus causes purulent bacterial infections with a considerable number of life-threatening complications and thus, is a serious cost factor in public health. Up to 50% of a given population could asymptomatically carry Staphylococcus aureus in their nares, thereby serving as a source for contact transmissions and endogenous infections. Nasal swab-based screening techniques are widely used to identify suchcarriers. This study investigated the skill of medical professionals in taking nasal swabs and the effect of teaching on improving bacterial recovery rates.

Methods: 364 persons with different medical educational background participated in this study. A novel anatomically correct artificial nose model was implemented and inoculated with a numerically defined mixture of Staphylococcus aureus and Staphylococcus epidermidis bacteria. Utilizing regular clinical swabs, participants performed screening of the inoculated nose models before and after standardized theoretical, visual, and practical teaching. Recovery of bacteria was measured by standard viable count techniques. Data were analyzed statistically by nonparametric tests.

Results: It could be demonstrated that combined theoretical and practical teaching improved bacterial recovery rates. Even experienced medical professionals increased their detection levels after training. Recovery rates of bacteria varied significantly between trained (158.1 CFU) and untrained (47.5 CFU) participants (Wilcoxon test, p<0.001; Kolmogorov-Smirnov test, p<0.001).

Conclusions: Swabs are commonly used to detect nasal carriage of Staphylococcus aureus in patients. The present teaching algorithm combined with the novel nose model offers an excellent precondition to improve knowledge and performance of this technique. Increased detection rates may prevent from contact transmission due to suboptimum hygienic patient handling. Consecutively, this effect could reduce costs for patient care. This study highlights the tremendous potential of combined theoretical, visual, and practical teaching methods in this field--and uncovers its actual necessity. Therefore, this training method can be recommended for all medical institutions.

Figure 1. Working instruction.

This working instruction was distributed to all participants. Each step was explained and demonstrated by the trainer.