Issue 9
Monday, 19 June 2017
Charles Darwin University
Associate Professor Phil Giffard
Associate Professor Phil Giffard

Contamination could affect Chlamydia results

By Paul Dale

Researchers at Menzies School of Health are hoping their work will improve clinical guidelines to minimise the probability of specimen contamination when testing for Chlamydia trachomatis.

Head of Laboratory Science at Menzies and lecturer in Medical Laboratory Science at CDU Associate Professor Phil Giffard, is the lead author of the report published in the journal “Sexually Transmitted Infections”.

The research addressed the possibility that an adult carer with Chlamydia-contaminated fingers could contaminate a urine specimen from a child.

”The detection of STI agents in young children is generally regarded as indicative of child sexual abuse,” he said. “However, there are conceivable mechanisms that could result in positive STI tests in the absence of sexual contact.”

Menzies researchers have been testing such mechanisms with a view to understanding their probability and/or developing procedures to avoid possible false positives of this nature.

The research indicated that given current clinical guidelines this type of contamination could not be ruled out.

“Modifications to guidelines for urine specimen collection procedures are suggested that could essentially eliminate the possibility of this occurring, and so eliminate uncertainty,” he said.

He said that the research provided additional confidence in the interpretation of a positive STI test in a young child, but it was important to note that it did not indicate whether false positives by this mechanism were occurring or provide any indication of the nature or prevalence of sexual abuse in the NT.

The research is available at:;gr.212647.116v1