Specimen Collection
SPECIMEN:
>1 g faeces
-
Fresh faecal collect of <2hours is preferable.
-
Avoid contamination (causes false positives).
-
Freeze the specimen if not analysed within 2 hours of collection.
-
A separate sample is required if other faecal tests have been requested.
-
Avoid collecting the sample from absorbent nappies as the reducing sugars in the fluid component of faeces might be disproportionally retained in the nappy.
-
This test will
NOT
be offered to patients aged 6 years and over.
This is due to significant background interference by normally coloured faecal fluid. If there is concern for lactose or fructose malabsorption, consider organising hydrogen and methane breath test (refer to:
Breath hydrogen and methane
in the LabPlus Test guide).
Turnaround Time: Within 1 week
4 days/ twice weekly
Only available 0800-1600 on weekdays
May be provided urgently upon request (0800 - 1600 weekdays)
Assay Method
Principle:
Qualitative colour production
Reagent:
AimTab, Germaine Laboratories
Analyser:
Visual inspection
Diagnostic Use and Interpretation
Germaine Laboratories AimTab tablets utilise Benedict copper reduction reaction.
Through visual inspection, the colour developed is matched against a standard colour chart.
The colour developed ranges from blue, to green, to brown then orange, in escalating concentrations of reducing substance.
Results are reported semi-quantitatively as:
Negative, Trace, +, ++, +++ and ++++
(highest reading)
Unlike hydrogen breath test which requires patient co-operation to collect expired air, reducing substance is mostly used in young children for the investigation of diarrhoea who are suspected of lactose or fructose malabsorption. Glucose can also be detected by this test.
However, note that rapid bowel transit of any cause e.g. from diarrhoea or short gut syndrome, can potentially cause a positive result. As the test detects any faecal reducing substances,
non-carbohydrate reducing compounds like salicylate, ascorbic acid, penicillin, cephalosporins or metabolites of some
sulpha drugs (if in high quantity) may cause a false positive result.
Sucrose is not a reducing sugar thus even if present in significant amount in faeces, it will not be detected by this test (unless it has been metabolised to fructose and glucose).
Also refer to: Breath hydrogen and methane
in the LabPlus Test guide
Breath Hydrogen and Methane
Osmolar gap - faecal
Contact Information
Emails to
chemicalpathologist@adhb.govt.nz
will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via
Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours
: contact
Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad
(Clinical Lead)
:
SamarinaM@adhb.govt.nz
ext. 22402
Dr Cam Kyle:
CampbellK@adhb.govt.nz
ext 22052
Dr Weldon Chiu:
WeldonC@adhb.govt.nz
ext. 23427
Dr Campbell Heron:
CHeron@adhb.govt.nz
ext. 23427
Dr Sakunthala Jayasinghe:
Sakunthala@adhb.govt.nz
ext. 23427
Specimen Transport Instructions for Referring Laboratories
Sample must be frozen before sending to LabPlus.
A separate sample is required if other faecal tests have been requested.