Staphylococcus Aureus Bloodstream Infection (SABSI)
Published: 12 March 2024
Published: 12 March 2024
Staphylococcus aureus bloodstream infection (SABSI) contributes to significant morbidity and mortality. Despite this, healthcare-associated SABSI is potentially preventable (ACSQHC 2021a).
Staphylococcus aureus (also known as S. aureus or golden staph) is one of around 40 species of Staphylococcus bacteria (RCHM 2018).
S. aureus are carried by approximately 20% of the population at any given time, with about 60% of people being colonised off and on during their lifetime (SA Health 2022).
S. aureus commonly inhabit the inside of the nose as well as the skin, where they are usually harmless and unnoticeable. However, if they are able to enter the bloodstream, they may multiply and cause SABSI (AIHW 2023).
Infection may be caused by bacteria from the patient’s own body or via the transmission of bacteria from another person (Mayo Clinic 2022a).
S. aureus infections range from mild to severe and may be life-threatening (Mayo Clinic 2022a).
In some cases, S. aureus can colonise food, leading to food poisoning (SA Health 2022).
Most S. aureus infections affect the skin (Healthdirect 2023a). These infections, known as staph skin infections, are often transmitted through skin-to-skin contact, touching contaminated objects or sharing items such as clothes and towels (Queensland Government 2017).
Staph skin infections include boils and abscesses, staphylococcal scalded skin syndrome (SSSS), impetigo, cellulitis and wound infections (Healthdirect 2023b; Better Health Channel 2015).
Staphylococcus aureus bloodstream infection (SABSI) occurs when S. aureus enters the bloodstream (AIHW 2023).
SABSI is a severe infection that may cause:
(Healthdirect 2023a; Better Health Channel 2015)
SABSI and other healthcare-associated infections are associated with complications such as prolonged hospital stays, increased healthcare costs and even death in the most serious cases (Monegro et al. 2023).
In healthcare settings, most cases of SABSI are related to poor hand hygiene among staff, invasive devices and healthcare procedures (ACSQHC 2021a).
S. aureus may be transmitted via contact with patients who have discharging wounds or infections or are colonised with the bacteria. If a staff member’s hands become contaminated with S. aureus, the bacteria may then be able to enter the bloodstream through open wounds, incisions or invasive devices (AIHW 2021; Health.vic 2015).
Someone who becomes colonised with S. aureus will not necessarily develop an infection, but if they do, this could occur from days to years after the initial exposure. However, even if someone is asymptomatic, they are infectious as long as S. aureus is being carried on their skin (SA Health 2022).
A SABSI is considered to be healthcare-associated (HA-SABSI) if either:
(ACSQHC 2021b)
If the infection does not meet these criteria, it is considered to be community-acquired (ACSQHC 2021b).
Over time, several strains of S. aureus have developed antibiotic resistance to certain medicines, including penicillin, methicillin and vancomycin (Better Health Channel 2015). These strains, known as methicillin-resistant Staphylococcus aureus (MRSA), are difficult to treat as fewer types of antibiotics will work effectively (Mayo Clinic 2022b).
For this reason, MRSA strains are associated with poorer patient outcomes (AIHW 2021).
MRSA strains can be acquired in both healthcare settings and community settings. Community-acquired cases of MRSA are known as community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) (WA DoH 2019).
These include:
(Healthdirect 2023a; CDC 2019)
SABSI is generally treated with intravenous antibiotics upon diagnosis (SA Health 2022).
Effective hygiene measures are essential in preventing the transmission of S. aureus and other healthcare-associated infections (Healthdirect 2023c). Healthcare workers should ensure they:
(Better Health Channel 2015; SA Health 2022)
Antibiotics must be used responsibly in order to reduce the risk of new resistant strains of S. aureus. Ensure that common, narrow-spectrum antibiotics are prescribed whenever possible (Better Health Channel 2015; Health.vic 2015).
Read: Appropriate Antibiotic use in Aged Care
Other ways to prevent the spread of S. aureus include:
(Better Health Channel 2015; SA Health 2022)
Surveillance refers to the monitoring and reporting of healthcare-associated infections in order to identify possible risk prevention strategies (VICNISS 2024).
In Australia, all cases of SABSI in acute public hospitals must be monitored and reported by their relevant jurisdictions (ACSQHC 2021).
When testing for SABSI, two sets of blood cultures should be taken from two different venepuncture sites. If these results don’t match, further investigation is required (ACSQHC 2021).
When a SABSI case is identified, an assessment should occur in order to determine whether the case meets the definition of a healthcare-acquired infection (see above) (ACSQHC 2021).
Question 1 of 3
Approximately how many known species of Staphylococcus are there?