Previous Article | Next Article 
Journal of Clinical Microbiology, March 1998, p. 852-852, Vol. 36, No. 3
0095-1137/98/$00.00+0
LETTERS TO THE EDITOR
Rapid Detection and Typing of Herpes Simplex Virus DNA in
Clinical Specimens by the Hybrid Capture II Signal Amplification Probe
Test
 |
LETTER |
In a recent study by Cullen et al. in which DNA hybridization by
the Hybrid Capture II method (HC-II) was compared with cell culture for
detection of herpes simplex virus (HSV) DNA (1), the culture
system missed 7 of 44 (15.9%) of the consensus HSV-positive specimens
from symptomatic ulcerative genital lesions. This raises questions
about the sensitivity of the culture method. The Discussion section
states that three of the negatives were due to greater sensitivity of
HC-II and four were due to differences in sampling or inhibitions of
culture.
In the culture method referenced in the Materials and Methods section,
that of Gleaves et al. (2), HSV antigen is detected by
fluorescein-labeled monoclonal antibody in MRC-5 cells cultured for 16 and 36 h and then fixed by acetone on coverslips. However, Cullen
et al. state that in their study HSV was detected by an enzyme-linked
immunosorbent assay with centrifuged cultures. No detail or reference
for their method is given.
Two apparently contradictory statements were also found. In Results it
is stated that one of the seven culture-negative patients had no
lesions but generalized symptoms suggestive of herpes, while in
Materials and Methods it is stated that specimens were from ulcerative
lesions. Secondly, the Discussion section states that it takes 3 to 7 days to obtain routine culture results, while in the introduction and
in Materials and Methods a period of 2 to 3 days is cited.
It is difficult to evaluate the results of the new method of diagnosis
due to confusion over comparative culture methods.
| |
REFERENCES |
| 1.
|
Cullen, A.,
C. Long, and A. Lorincz.
1997.
Rapid detection and typing of herpes simplex virus DNA in clinical specimens by the Hybrid Capture II signal amplification probe test.
J. Clin. Microbiol.
35:2275-2278[Abstract].
|
| 2.
|
Gleaves, C. A.,
D. J. Wilson,
A. D. Wold, and T. F. Smith.
1985.
Detection and serotyping of herpes simplex virus in MRC-5 cells by use of centrifugation and monoclonal antibodies 16 h postinoculation.
J. Clin. Microbiol.
21:29-32[Abstract/Free Full Text].
|
| | | | |
Frank, J. Michalski, Ph.D.
5 Ridgeway Ct.
West Orange, New Jersey 07052
|
| |
AUTHORS' REPLY |
Dr. Michalski raises a salient point regarding the sensitivity of our
culture method. Culture is often considered the "gold standard" for
such comparisons; however, culture is subject to variations in
sensitivity related to interlaboratory technique. This variability is
one reason a test system like the Hybrid Capture II (HC-II) is
attractive, as it offers sensitive and reproducible DNA detection.
It is generally accepted that amplified-nucleic acid tests are
equivalent in sensitivity to or more sensitive than traditional culture. We have shown that HC-II is more sensitive than either rapid
or traditional culture for cytomegalovirus (3) and
Chlamydia trachomatis (1). Thus, it is not
surprising that this study showed HC-II to be at least equivalent in
sensitivity to culture.
The reference for our HSV culture was a study by Gleaves et al.
(2), which compared a shell vial HSV antigen detection method with traditional cell culture for HSV. It was our intention that
the traditional culture method described by Gleaves et al. be taken as
a general reference for HSV culture. For our study, cultures were grown
for 2 to 3 days and were then centrifuged; this was followed by an
enzyme-linked immunosorbent assay to detect HSV. We regret any
confusion that our incomplete description may have caused.
Dr. Michalski identifies two apparent contradictions in our paper. The
first is regarding the description of one patient as having generalized
symptoms suggestive of herpes but no lesions; however, the study
population was described as patients with lesions. In cases where
herpes was suspected but no lesions were present, a swab of the cervix
was collected. There were only a few patients meeting these criteria.
In the case mentioned, HC-II detected HSV from a cervical swab whereas
culture did not.
The second apparent contradiction relates to a statement in the
introduction that culture detects most cases of HSV in 2 to 3 days but
that cultures are routinely held for up to 7 days in order to detect
low titers or asymptomatic infection. In our study, we did not perform
culture for 7 days, as noted in Materials and Methods. However, the
general comment that culture can take between 3 and 7 days is not
inaccurate.
Lastly, we appreciate Dr. Michalski's desire for assessing the true
performance of the HC-II test in comparison with culture. We intend to
subject the HC-II HSV test to more rigorous clinical evaluations in the
future.
| |
REFERENCES |
| 1.
|
Cullen, A. P.,
P. A. Arthur,
L. He,
C. D. Long,
D. Shook,
E. W. Hook III,
K. Smith, and A. T. Lorincz.
1997.
Evaluation of the Digene Hybrid Capture® II CT/GC test for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in clinical specimens. Presented at the International Congress of Sexually Transmitted Diseases, Seville, Spain, 21 October 1997
.
|
| 2.
|
Gleaves, C. A.,
D. J. Wilson,
A. D. Wold, and T. F. Smith.
1985.
Detection and serotyping of herpes simplex virus in MRC-5 cells by use of centrifugation and monoclonal antibodies 16 h postinoculation.
J. Clin. Microbiol.
21:29-32.
|
| 3.
|
Veal, N.,
C. Payan,
D. Fray,
L. Sarol,
O. Blanchet,
S. Kouyoumdjian, and F. Lunel.
1996.
Novel DNA assay for cytomegalovirus detection: comparison with conventional culture and pp65 antigenemia assay.
J. Clin. Microbiol.
34:3097-31[Abstract].
|
| | | | |
Attila Lörincz, Ph.D.
Allison Cullen, M.
S.
Carole Long, B.S.
Research & Development Digene Corporation 2301-B Broadbirch Dr. Silver
Spring, Maryland 20904
|
Journal of Clinical Microbiology, March 1998, p. 852-852, Vol. 36, No. 3
0095-1137/98/$00.00+0
Top
Letter
References
