Læknablaðið - 15.07.1995, Blaðsíða 15

LÆKNABLAÐIÐ 1995; 81
531
Clinical Evaluation of a
Rapid Polymerase Chain Reaction
(PCR) Assay
for the Detection of Chlamydia trachomatis in
Specimens from High Risk Patients
Ólafur Steingrímsson11, Jón H. Ólafsson21, Sigfús M. Karlsson1’, Rannveig Pálsdóttir2)
Steingrímsson Ó11, Ólafsson JH21, Karlsson SM11,
Pálsdóttir R21
Læknablaðið 1995; 81: 531—4
A Rapid Polymerase Chain Reaction Assay (Ampli-
cor®-PCR) was evaluated for the detection of Chla-
mydia trachomatis in specimens from 179 high risk
patients. The results were compared to McCoy cell
culture and specimens were retested with Ampli-
cor® and primers for the Major Outer Membrane
Protein (MOMP) gene when discrepancy occurred.
Of 88 females enrolled in the study, 30 were infected
(34%). Sensitivity, selectivity, predictive value of a
positive (PVP) and a negative (PVN) on endocervi-
cal specimens were 97%, 96.5%, 96.5% and 98%
respectively. Of 91 male urine specimens, 33 (36%)
came from infected patients. The sensitivity and
specificity of the Amplicor® assay was 94% and 74%
respectively for male urine specimens and the PVP
and PVN were 72% and 96% respectively. The sen-
sitivity was low on the original run on urethral speci-
mens but the majority of false negative specimens
became positive when retested. Amplicor® per-
formed on urine samples was the most sensitive test
for detecting Chlamydial infections in males.
From the Departments of Microbiology’1 and Dermato-Ve-
nereology21 at the University of lceland, Reykjavík, lceland.
Correspondence; Ólafur Steingrímsson, Department of Mi-
crobiology, P.O. Box 1465,101 Reykjavík, lceland. Phone:
560 1900. Fax: 560 1904.
Introduction
Sexually transnritted infections caused by
Chlamydia trachomatis have been a significant
Frá sýklafræðideild Landspítalans”, húð- og kynsjúkdóma-
deild Landspítalans21. Fyrirspurnir, bréfaskipti: ÓlafurStein-
grímsson sýklafraeðideild Landspítalans, 101 Reykjavík.
health care problem in the Western world in
recent years (1,2). Rapid diagnosis of Chlamy-
dial infections is of major importance for effi-
cient treatment of individual patients and for
effective contact tracing. Culture is time con-
suming and in recent years a number of rapid
methods have been introduced for direct de-
tection of Chlamydial antigens in patient speci-
mens. Although these methods lack somewhat
in sensitivity compared to culture, they have
come into widespread use (3-8). Recently,
Rapid Polymerase Chain Reaction (PCR) As-
says superior in sensitivity to older rapid meth-
ods, have been introduced (9). Molecular tech-
niques for the detection of Chlamydia tracho-
matis require complicated techniques and
competence not available in most routine lab-
oratories. Roche Molecular Systems has re-
cently marketed a commercial PCR, suited for
use in clinical laboratories (10-12). The present
study is a clinical evaluation of this PCR assay
for the detection of Chlamydial infections in
cervical specimens from females and urethral
swabs and urine from males.
Materials and methods
Patient population and specimen collection:
The patients were high risk males and females
attending the State Clinic for Sexually Trans-
niitted Diseases (STD) in Reykjavík Iceland.
Patients were enrolled in the study if they had
symptoms or were contacts of patients, known
to be infected with Chlamydia trachomatis. Pa-
tients were excluded if they had received anti-
biotics during the week prior to specimen col-
lection.
If the male patients had a discharge, it was