Urinary NAAT for Chlamydia trachomatis

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Chlamydia
trachomatis Testing Sensitivity in Midstream Compared With First-Void Urine
Specimens.

Ann
Fam Med. 2012; 10(1):50-3 (ISSN: 1544-1717)

Mangin D; Murdoch D; Wells JE; Coughlan E; Bagshaw S;
Corwin P; Chambers S; Toop L

Primary Care Research Unit, Department of General Practice, University of
Otago, Christchurch, New Zealand.

PURPOSE Traditionally first-void urine specimens are
used to test for Chlamydia trachomatis. In contrast, midstream urine specimens
are traditionally recommended for microscopy and culture of presumptive
bacterial urinary tract infections. The ability to test for both C trachomatis
and urinary tract infection on a single midstream urine specimen would greatly
aid clinical practice, as an urinary tract infection is an extremely common
complaint in primary care. This study set out to determine how well positive C
trachomatis results obtained on first-void specimens would correlate with
positive findings in matched midstream specimens. METHODS One hundred women
with a first-void urine specimen positive for C trachomatis also provided midstream
specimens for comparison. All specimens had C trachomatis testing performed
using a DNA detection method.
RESULTS Of the 100 eligible participants with a first-void specimen positive
for C trachomatis, 96 (96%) also had a positive midstream specimen (95% exact
confidence limits, 90.1%, 98.9%). CONCLUSIONS These results suggest that by
using newer nucleic acid
amplification techniques (NAATs), timing of specimen collection is not
so important in testing for C trachomatis as previously thought. The sensitivity
of NAAT testing on midstream urine specimens in women is sufficiently
equivalent to testing on first-void specimens to consider in clinical practice
and research settings where first-void specimens have formerly been collected.