MSSA Nasal Colonization Prevalence and Clinical Impact

General Population Prevalence

• The 2024 and 2016 guidelines published in The Journal of Thoracic and Cardiovascular Surgery report that 15 %–30 % of the general population are nasal carriers of methicillin‑susceptible Staphylococcus aureus (MSSA), with the 2016 guideline explicitly stating “twenty to thirty percent of the general population are carriers of Staphylococcus aureus”【1】【2】【3】.

• The 2005 Clinical Infectious Diseases guideline indicates that nasal colonization with any Staphylococcus aureus (including MSSA and a small proportion of MRSA) occurs in 20 %–40 % of the general population【4】.

Proportion of MRSA Within Total S. aureus Nasal Carriage

• The 2024 guideline estimates that approximately 5 % of the general population carry methicillin‑resistant Staphylococcus aureus (MRSA), acknowledging regional and healthcare‑exposure variability【1】.

• The 2016 guideline notes that 5 %–15 % of patients admitted to intensive‑care units are MRSA carriers, a rate markedly higher than community prevalence【2】【3】.

Clinical Consequences of MSSA Nasal Colonization

• According to the 2024 guideline, individuals colonized with MSSA have a 3‑ to 6‑fold increased risk of developing MSSA surgical‑site infections, supporting the relevance of screening and decolonization in high‑risk surgical groups such as cardiac surgery patients【1】.

• The same 2024 guideline, together with the 2016 guideline, emphasizes that screening and decolonization strategies are particularly pertinent for high‑risk surgical populations due to the elevated infection risk associated with MSSA carriage【1】【2】.