We searched Pubmed with the following search terms: “Staphylococcus aureus”, “colonisation”, “carriage”, “nose”, “nasal”, “vestibulum nasi”, “mucosa”, “nasal”, “nosocomial”, “epidemiology”, “determinants”, “risk factor”, “treatment”, and “infection”. The following limits were used: English language, abstract, and human studies. We identified additional articles by searching the reference lists of existing articles.
ReviewThe role of nasal carriage in Staphylococcus aureus infections
Introduction
Staphylococcus aureus is both a human commensal and a frequent cause of clinically important infections (figure 1).1 Although the prevalence of meticillin-resistant S aureus (MRSA) is still very low in northern European countries,2 there is a worldwide increase in the number of infections caused by MRSA. Vancomycin is one of the last therapeutic options available for MRSA infections. The recent isolation of vancomycin-resistant MRSA strains in the USA is a major cause for concern.3 Therefore, the prevention of staphylococcal infections and reduction of the spread and emergence of MRSA are essential.
The association between S aureus nasal carriage and staphylococcal disease was first reported by Danbolt in 1931, who studied furunculosis.4 The increasing incidence of penicillin-resistant S aureus hospital infections since 1947 emphasised the need for a better understanding of the pathogenesis of staphylococcal disease. Subsequently, numerous studies confirmed Danbolt's finding.5, 6, 7, 8, 9 A causal relation between S aureus nasal carriage and infection is supported by the fact that the nasal S aureus strain and the infecting strain share the same phage type or genotype.8, 10 Furthermore, nasal application of an antistaphylococcal drug temporarily decolonises the nose and other body sites, which prevents infection.11
Our knowledge of the mechanisms, risks, and treatment of S aureus nasal carriage has greatly expanded over the past decade. Table 1 presents an overview of major events in S aureus research. Here, we focus on the latest insights into the determinants of S aureus nasal carriage and the risks of infection associated with S aureus nasal carriage. Most studies were done in western countries, so conclusions drawn can not always be generalised.
Section snippets
S aureus nasal carriage patterns
S aureus colonises the skin and mucosae of human beings and several animal species.5 Although multiple body sites can be colonised in human beings, the anterior nares of the nose is the most frequent carriage site for S aureus.5 Extra-nasal sites that typically harbour the organism include the skin, perineum, and pharynx.5, 23, 24, 25 Other carriage sites including the gastrointestinal tract,5, 26 vagina,27 and axillae5, 25, 28 harbour S aureus less frequently (figure 2).
Most studies on S aureus
Community-acquired infections
Most studies regarding the risks of acquiring S aureus infections in the community concern skin and soft tissue infections. Several, mostly older, studies investigated the relation between S aureus nasal carriage and skin infections,121 including furunculosis,122, 123 impetigo,124 sycosis barbae,10, 122, 125 and stye.126 On average, 80% (range 42–100%) of those with skin lesions were S aureus nasal carriers, and 65% (range 29–88%) had the same phage type in the nose and lesion.
In one large
Conclusions
Many studies have been published on S aureus nasal carriage—a Pubmed search with the terms “Staphylococcus aureus” and “nasal” gives 1383 hits. Based on these studies and the results of contradicting twin studies183, 184 a simple Mendelian trait probably does not explain the different S aureus nasal carrier states.38, 48 The repeated exposure to S aureus in the (household) environment is considered to be an important determinant of S aureus nasal carriage, probably more important than the
Search strategy and selection criteria
References (184)
- et al.
Low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) at hospital admission in the Netherlands: the value of search and destroy and restrictive antibiotic use
J Hosp Infect
(2004) - et al.
Risk and outcome of nosocomial Staphylococcus aureus bacteraemia in nasal carriers versus non-carriers
Lancet
(2004) - et al.
Superficial staphylococcal infection
Lancet
(1952) - et al.
Pulsed field gel electrophoresis as a new epidemiological tool for monitoring methicillin-resistant Staphylococcus aureus in an intensive care unit
J Hosp Infect
(1991) - et al.
Whole genome sequencing of meticillin-resistant Staphylococcus aureus
Lancet
(2001) - et al.
Long-term study of nasal staphylococci among hospital personnel
Am J Surg
(1969) - et al.
Persistent (not intermittent) nasal carriage of Staphylococcus aureus is the determinant of CPD-related infections
Kidney Int
(2005) Incidence of Staph. aureus in the anterior nares of healthy children
Lancet
(1949)- et al.
Postoperative infection with meticillin-resistant Staphylococcus aureus and socioeconomic background
Lancet
(2004) - et al.
Colonisation by Streptococcus pneumoniae and Staphylococcus aureus in healthy children
Lancet
(2004)