Læknablaðið - 15.07.1995, Blaðsíða 34

546
LÆKNABLAÐIÐ 1995; 81
asymptomatic patients have been shown to be
important for the control of these infections
(5,6) but their relative importance is unknown.
In this study the results of diagnostic tests for
infections caused by C. trachomatis, perform-
ed in Iceland from 1982 to 1994 were reviewed.
Materials and methods
The population of Iceland increased during
the study period, from 231,958 in 1981 to
266,786 in 1994. Diagnostic tests were only
available in the Department of Microbiology,
at the National University Hospital in Reykja-
vík until December 1990, when antigen detec-
tion tests (Chlamydiazyme®) became available
in the Department of Laboratory Medicine,
the Regional Hospital, Akureyri, a facility
serving a population of approximately 15,000.
All records of test results for Chlamydial in-
fections performed in Iceland, from January
1982 to the end of 1994, were reviewed. Cell
culture for C. trachomatis became available in
Iceland in December 1981, the enzyme linked
immunoassay, Chlamydiazyme® in 1985 and
the polymerase chain reaction (PCR) was in-
troduced in 1994.
The records were kept in hand-written log-
books. Test results from 1990-1994, and for
limited periods prior to that, were recorded on
computer and were available for a more de-
tailed analysis. The origin, the type of speci-
men, type of test performed and the test results
were noted in all instances. The examinations
performed in two clinics, the Sexually Trans-
mitted Diseases (STD) Clinic and the Depart-
ment of Obstetrics and Gynecology were re-
viewed. The number of examinations per an-
num and the rate of positive examinations for
each location were recorded. If specimens for
two or more tests were obtained at the same
time, the tests were considered one examin-
ation. If culture and Chlamydiazyme® were
performed simultaneously and culture was
negative, the examination was considered neg-
ative, even if Chlamydiazyme® was positive.
The reason for submitting the specimens was
unknown in the majority of instances. Speci-
mens submitted to laboratories were identified
with a code number in order to assure anonym-
ity of patients. The age and sex of the patient
were usually recorded.
Specimens for culture for C. trachomatis
were collected on cotton swabs (Medical Wire
Co.), immediately placed in transport medi-
um, cooled and transported to the laboratory
within three hours. In the laboratory the speci-
mens were frozen at -70°C until cultured on
McCoy cell monolayers (7). Each specimen
was cultured in two vials. After 72 hours one
was stained with iodine and examined. If the
result was inconclusive, or Chlamydiazyme®
had been performed and was positive, a sub-
culture was performed from the second vial.
Blind subcultures were not performed. Chla-
mydiazyme® was performed according to the
manufacturer’s (Abbott Laboratories) instruc-
tions. Blocking assays were utilised from 1990.
The Amplicor® PCR was performed on a Per-
kin Elmer thermocycler according to the man-
ufacturer’s (Roche Molecular Systems) in-
structions.
Results
The number of cultures performed was
41,985, the number of Chlamydiazyme® tests
was 72,176 and the number of PCR tests 9300
(total 123,461). The total number of exantin-
ations was 101,574 with 14,462 positive results
(figure 1). The usage of the different tests is
shown in figure 2. The total number of exam-
inations in the STD Clinic was 27,583 out of
which 6,422 were positive (figure 3). The total
number of examinations performed in the De-
partment of Obstetrics and Gynecology was
27,066 with 2,257 positive examinations (fig-
ure 4). The clinic was the only one that consis-
Table I. Medicm age and number of male patients examined in the STD Clinic 1990-1994.
Patients examined Patients infected
Year N Median age N Median age (%) positive
1990 1452 24 250 22 (17.2)
1991 1515 23 319 22 (21.1)
1992 582 22 310 22 (19.6)
1993 1598 22 261 22 (16.3)
1994 1932 22 369 22 (19.1)