Detection and clinical relevance of Staphylococcus aureus nasal carriage: an update

Abstract

Staphylococcus aureus nasal carriage is a well-defined risk factor of infection with this bacterium. The increased risk of S. aureus infection in nasal carriers is supported by the fact that the strains isolated from both colonization and infection sites are indistinguishable in most of the cases. Persistent nasal carriage seems to be associated with an increased risk of infection and this status could be defined now in clinical routine by using one or two quantitative nasal samples. There is evidence for supporting the detection of nasal carriage of S. aureus in patients undergoing cardiac surgery and in those undergoing hemodialysis in order to implement decolonization measures. More studies are needed to determine which carriers have the highest risk of infection and why decolonization strategies failed to reduce S. aureus infection in some other groups of patients.

Keywords::

• carrier state
• nasal mucosa
• persistent carriage
• risk factor
• screening test
• Staphylococcus aureus

Financial & competing interests disclosure

PO Verhoeven received travel grants from Becton Dickinson, Cepheid, Alere. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Nasal carriers of Staphylococcus aureus were recently reclassified into two types: persistent and others.

• Simplified methods are now available for predicting the patient nasal carriage status, persistent or not, on a routine basis.

• Unlike others, persistent nasal carriers of S. aureus exhibit a higher nasal bacterial load, a higher dispersion of S. aureus in the environment and are at higher risk of infection with this bacterium. These observations suggest that this population should be targeted for preventive strategies during at-risk situations.

• S. aureus nasal carriage is a well-defined risk factor of S. aureus infection in almost all of the categories of patients that have been studied.

• S. aureus infections are usually caused by the strain carried in the nose of infected patients.

• The role of extra nasal sites of S. aureus carriage in the development of infection due to this bacterium remains poorly investigated.

• Screening of S. aureus nasal carriage should be done in patients undergoing cardiac surgery or undergoing hemodialysis or continuous peritoneal dialysis in which nasal decolonization of carriers leads to reduce S. aureus infection rate.

Notes