MEDIA RELEASE
18 NOVEMBER 2015
NEW RECOMMENDATIONS FOR FAECAL PATHOGEN SCREENING
AIMS TO REDUCE UNNECESSARY TESTING
Today, the Royal College of Pathologists of Australasia (RCPA) announces new
recommendations for faecal pathogen screening, in order to prevent the continued and
unnecessary over diagnosis and over treatment. The new guidelines are in relation to DNAbased diagnostic methods (PCR) in the detection of Dientamoeba fragilis and Blastocystis
species.
Dr Harsha Sheorey, spokesperson on faecal pathogens for the RCPA, says,
“The role of both Dientamoeba fragilis and Blastocystis species as gastrointestinal
pathogens is highly controversial. These organisms have been difficult to identify by
microscopy in the laboratory. It is only due to the recent introduction of DNA-based
diagnostic methods, referred to as PCR, that we now know that these organisms are much
more common than previously thought.”
Currently, 16 percentage of all faeces test positive by PCR for D. fragilis in Australian labs
and children below the age of 10 are four times more likely to have D. fragilis in their faeces
than adults. These organisms are found in the faeces of both symptomatic and
asymptomatic individuals as well as in a number of animal species all around the world.
“The PCR techniques have led to unnecessary diagnoses and the over treatment of these
two organisms. This results in needless anxiety amongst patients and parents and can even
cause possible harm due to the disruption of the normal flora from the use of antibiotics as
treatment. In addition, laboratories are being asked to ‘test for clearance’ in asymptomatic
patients, adding to the cost and time of pathology testing with no clinical benefit,” said
Sheorey.
President of the RCPA, Associate Professor, Peter Stewart, says,
“Patient care is always top of mind in everything that we do. In this instance, laboratory
science is ahead of clinical science in this respect, with many clinicians unaware of the
limitations of new tests. Our new recommendations aim to reduce the use of testing that is
currently adding time, cost and anxiety, however is not providing a benefit to the patient.”
The RCPA’s new recommendations
1. When testing for faecal pathogens, consider using a multiplex PCR without
Dientamoeba fragilis and Blastocystis species. If there is a specific request to detect
these organisms, microscopy (including stained smears) after discussion with a
medical microbiologist, or PCR may be used. Where PCR is used, its diagnostic
limitations in this context must be understood.
2. If a smear or PCR is positive, the report should contain a comment highlighting the
questionable pathogenicity of these two organisms. Examples of comments suitable
to include on pathology reports are as follows:
a. Blastocystis: The pathogenic role of Blastocystis spp has not been established.
Most cases do not require treatment and antimicrobial treatment will often
not clear the protozoa but may disrupt the normal gut flora. It can be
acquired by contact with animals (eg pets) or contaminated water. Animal
strains cannot be differentiated by the current available tests. If
symptomatic, other causes should be excluded (eg other infections, Irritable
Bowel Syndrome, food intolerances etc). Screening for clearance of the
organism or testing of family members is not recommended.
b. Dientamoeba: The pathogenic role of D.fragilis has not been established.
Most cases do not require antimicrobial treatment and this will often not
clear the protozoa but may disrupt the normal gut flora. If symptomatic,
other causes should be excluded, eg other infections, Irritable Bowel
Syndrome, food intolerances etc. Screening for clearance of the organism or
testing of family members is not recommended.
For more information, visist our website www.rcpa.edu.au or see our updates on Twitter @PathologyRCPA - and Facebook. #PathologyStory #IPD2015 #MedicineIsPathology #RCPA
ENDS
About the Royal College of Pathologists of Australasia:
The RCPA is the leading organisation representing pathologists in Australasia. Its mission is
to train and support pathologists and to improve the use of pathology testing to achieve
better healthcare.
Media enquiries:
Dr Debra Graves
Chief Executive Officer
The Royal College of Pathologists of Australasia
+61 2 8356 5858
Debrag@rcpa.edu.au
Marco Navarria
Senior Account Manager
S2i Communications
+61 2 9262 4766
Marco@s2i.com.au