Microbiology / urine changes from 11 December

From Monday 11 December 2023, the Microbiology department at Awanui Canterbury will be introducing changes to urine samples received by the laboratory.

  1. Samples must be accompanied by relevant clinical details in order to be processed. Samples without relevant clinical details will not be processed.
  2. Culture will only be performed if microscopy shows a white cell count of ≥10 x 106/L  for males and ≥30 x 106/L for females, except in select circumstances (details below).

Changes are being introduced for patient benefit, to ensure appropriate testing and prevent over-reporting and over-treatment. These criteria have been in place across a large number of New Zealand diagnostic laboratories (both Awanui and non-Awanui) for a number of years with no evidence of detrimental effect on patients, referrers, or the corresponding health system. By aligning our methods, we can ensure that patients receive best practice testing no matter where they live.

Clinical details

A brief summary of the patient’s specific urinary symptoms, accompanied by any other useful information such as pregnancy, immunocompromising conditions, current antibiotics and antibiotic allergies, etc. all contribute to how the sample is processed in the laboratory, what susceptibilities are performed and how the result is reported back to the requestor.

A table has been provided below for examples of appropriate clinical details and situations.

Use of details such as ?UTI or similar is discouraged as it doesn’t provide the detail required to guide laboratory testing, including which antibiotics are reported and the interpretation of susceptible or resistant results. A test request for ‘MSU’ is also not useful as this is a specimen type rather than a test. If culture is required, then this should be the test requested.

When to send a sample

Health pathways[1] and BPAC[2] advise that urine samples should be sent to the laboratory to aid in the diagnosis of complicated UTIs or those at a higher risk of complications (for example men, children, pregnant women, pyelonephritis, recurrent UTI) and in most situations are not required for uncomplicated UTI, test of cure, asymptomatic screening, or catheterised patients without systemic symptoms.

Urine culture:

Culturing all urine specimens regardless of WBC count leads to over-reporting of contaminating organisms, over-diagnosis, and over-treatment. Without pyuria, in most clinical settings, there is no indication for antibiotic therapy.

We will continue to culture samples irrelevant of WBC count where there are appropriate clinical indications (e.g. children <12 years old, pre-urological surgery, pregnancy, neutropenia).

Contacting the laboratory

As the clinician you can contact the laboratory and add relevant clinical details or to request a culture even if the sample has a white cell count below threshold. The clinical microbiologist is also available if required for guidance on treatment or testing.

Contact details direct to the laboratory will be included on reports when testing has not been performed. The Microbiology department at Awanui Canterbury can be contacted directly by emailing cscl.micro@awanuilabs.co.nz (preferred), or phone 03 3590957. Please don’t hesitate to contact the lab if you have any questions regarding these updates.

Dr Aaron Keene (Clinical Microbiologist)Jacquie Leaman (Head of Microbiology)

Aaron.Keene@awanuilabs.co.nz


[1] https://canterbury.communityhealthpathways.org/

[2] https://bpac.org.nz/2021/uti.aspx