Diseases > Varicella
Collecting
Varicella Zoster Virus (Chickenpox and Shingles)
Specimens
|
At
a Glance:
This page is for healthcare professionals. The page includes
a link to a video that describes how to collect specimens,
includes a specimen collection form, and describes where to
submit the form. Contact information is available should you
have any questions. |
|
|
|
|
Contents
of this page: |
|
|
|
Why
lab confirmation of varicella cases is
becoming more important |
Laboratory
confirmation of varicella zoster virus is not
normally required, because varicella diagnosis
is most commonly made by clinical assessment.
Laboratory testing has been recommended to
confirm the diagnosis of severe or unusual
cases or to determine susceptibility to varicella.
However, as varicella incidence continues to
decline, the likelihood of clinical misdiagnosis
increases. Varicella in vaccinated persons
is usually mild or atypical and can pose particular
challenges for clinical diagnosis. Therefore,
laboratory confirmation of varicella cases
is becoming more important, as fewer cases
are seen and a higher proportion of these few
are vaccinated.
Instructions for collecting specimens
Below is to a video developed
for health care professionals to illustrate
the most appropriate procedures for collecting
varicella zoster virus (VZV) skin lesions and
blood specimens. Also, be sure to download
the specimen collection form
which should be sent along with the specimen
to the CDC.
Video
Files and Collection Form |
Length
of video is 4 minutes.
Links
to download video file |
File* |
Size |
Video file
(compressed for quick download) |
|
2
MB |
Video
file (higher quality, non-compressed
for BroadBand or local computer use) |
|
14
MB |
Video
file (highest quality, non-compressed
for those connecting via DSL or accessing
via a local area network) |
|
16
MB |
Link
to download collection form |
Printable |
Accessible |
Specimen
collection form |
.pdf version
|
|
*
Windows Media Player can be used to view these
files. If you do not have Windows Media Player,
it can be obtained as a free download from
the Microsoft website at http://www.microsoft.com/windows/windowsmedia/players.aspx
** The text
version is provided for those that require
text-only documents for screen-reader devices.
Please contact NIPINFO@cdc.gov via email, if
you need further any assistance.
Script
of Video |
This video outlines procedures for collecting
varicella skin lesions and blood specimens.
Skin lesions are the preferable method for
laboratory confirmation of varicella. Blood
specimens should be used to test for varicella
immunity.
There
are 3 types of lesions you will see most often
resulting from varicella zoster virus, a scabbed
or crusted lesion; a maculo-papular lesion,
which is a lesion with a raised red bump; or
a vesicular lesion, which is a blister-like
or fluid filled lesion.
To
collect a scab for varicella zoster virus testing,
begin by gently lifting the scab from the lesion.
Once the scab is collected, place it in a container
such as a swab specimen tube or a plastic baggie.
If there is more than one scab, place each
scab individually in different containers.
The
most effective technique for collecting cells
from a maculopapular lesion or fluid from a
vesicular lesion is the same, though for maculopapular
lesions it is a greater challenge to ensure
that enough skin cells are collected. Lesions
in vaccinated individuals are likely to be
atypical, macular only or papular only, but
obtaining specimens from papular lesions is
possible using the following technique. Use
the edge of a clean slide to loosen and collect
skin cells or fluid from the lesion as shown
here. Then, using a sterile swab, rub the lesion
vigorously enough to ensure that skin cells
or fluid are collected. To ensure an adequate
amount of skin cells is collected, particularly
with maculopapular lesions, we recommend also
using the swab to wipe the skin cells off the
edge of the slide used to scrape the lesion.
You may also press the slide directly to the
lesion to collect skin cells or fluid as shown
here. This technique is especially effective
for vesicles where a “smudge” should
be visible. To ensure that skin cells or fluid
are on the slide, compare it to a clear slide
under light, as shown here.**
To
collect a blood specimen for varicella immunity
testing perform a finger stick on the individual.
Soak the circle on the filter paper with blood
ensuring that the circle is completely full
and check to see that blood has soaked through
to the other side. Then soak the remaining
circle, and again ensure that blood has soaked
through both sides of the filter paper. Allow
the blood to dry before packaging the filter
paper. Venupuncture is also an acceptable method
for blood collection. Collect at least 1 ml
of blood into a serum-seperator vaccutainer
tube. Before storage or shipping, separate
the serum from the cells in a centrifuge for
15 minutes.
For
more information on varicella zoster virus
specimen collection, storage, and handling,
please contact:
Centers for
Disease Control and Prevention
National VZV Laboratory
1600 Clifton Road, NE
Mailstop G-18
Atlanta, GA 30333
Phone: (404) 639-3667
Fax: 404-639-4056
Email: vzvlab@cdc.gov
|