Awanui Labs across Te Waipounamu (South Island) are planning a major change in the way community skin swab cultures are reported. You will notice this change from 3 November 2025.
Why is this happening?
We are making this change to support community antimicrobial stewardship efforts. Skin and soft tissue infections are clinical diagnoses, based upon the presence of consistent clinical features (such as redness, soreness, swelling, presence of pus). However, review of community prescribing data demonstrates that in half of cases, antibiotics are prescribed only after a swab result showing growth of S. aureus or a beta haemolytic streptococcus appears in a provider inbox. This implies that the swab result itself influences the decision of whether to treat or not, rather than it being an empiric decision based on the clinical findings at the time of consultation.
Skin and soft tissue infections are caused by the same range of organisms that can be harmless colonisers, and interpretation of culture results from non-sterile sites, such as wounds, can be difficult. The swab result per se does not differentiate colonisation from infection. Since most patients can be successfully treated empirically with flucloxacillin or cefalexin, the main value of a swab is to rule out MRSA or unusual pathogens which would warrant a change from these standard empiric choices of antibiotics. Rates of MRSA across Te Waipounamu are very low, <5%.
Experience from Awanui Labs Wellington
This swab reporting change has already been made in the greater Wellington and Taranaki regions and has proven to be a great success. Feedback from community providers since the change has been almost universally positive and our Awanui Wellington colleagues have been able to monitor the effects of the change by matching laboratory and antibiotic dispensing data. This demonstrated a drop in reactive dispensed antibiotics on the basis of the microbiology report from 50% to 25%, with no adverse clinical impact (published in the Journal of Clinical Microbiology https://doi.org/10.1128/jcm.00342-24). We will also monitor the situation post this change across Te Waipounamu.
What is the change?
There is no change to the receiving or processing of swabs; the change relates to reporting.
However, from 3rd November 2025, organisms that are susceptible to empiric antibiotics (e.g. flucloxacillin susceptible S. aureus, or beta haemolytic streptococci) will not be reported from community wound swabs. Rather, only pathogens which are unlikely to be covered by standard treatment (e.g. MRSA) will be reported. A comment will be added to the report informing the requestor that no organisms resistant to standard treatment have been detected.
The laboratory will continue to culture and identify organisms in the usual way, so that if for some reason a result is still required it is possible to contact the laboratory to get this extra information straight away.
Clinical details are mandatory and are very important since there will be some exclusions, where reporting would be unchanged from the current process:
- intolerance to flucloxacillin or cefalexin
- children aged <1 year
- patients with recurrent boils or staphylococcal infections
- hospitalised patients
- unusual exposure history such as water or animal bites
- where a specified antibiotic has been prescribed empirically
- ear and nose swabs.
Further information
Feedback on this proposal is welcomed and encouraged, by COB Tuesday 23 September. Please send through to Tash Bambry, Awanui Labs regional relationships manager, tash.bambry@awanuilabs.co.nz
We will hold an online meeting where requestors can hear more about this important proposal and ask any further questions on Thursday 18 September at 4pm – If you would like to join us online please email tash.bambry@awanuilabs.co.nz for a link to the meeting.
With thanks, from the Te Waipounamu Clinical Microbiologists:
Dr Juliet Elvy, juliet.elvy@awanuilabs.co.nz
Dr Aaron Keene, aaron.keene@awanuilabs.co.nz
Prof James Ussher, james.ussher@awanuilabs.co.nz