be run daily if the test does not have internal controls. The
ZstatFlu-II test is in this category. The added requirement for
controls could be a burden in some situations. It should also be
emphasized that as of this writing, the ZstatFlu-II test has not
gone through a 510(k) ﬁling process with the Food and Drug
Administration (FDA) and is therefore not an FDA-approved
test for inﬂuenza.
The study reported here was based on nasal aspirate speci-
mens. This is the best specimen available for both of the rapid
tests (11, 15). Becton Dickinson’s Directigen test does permit
the use of throat swabs (11, 15). Testing based on throat swabs
was less sensitive (11, 15). How the ZstatFlu-II test would
function with a nasal swab or a throat swab specimen is not
known at this time.
The inability of the ZstatFlu-II test to distinguish inﬂuenza
virus type A from type B may or may not be a problem.
Amantadine will treat only inﬂuenza virus type A, but the
newer treatments are effective for both types of inﬂuenza vi-
ruses (9, 21). In the latter case, the lack of information regard-
ing the precise type of inﬂuenza virus infection is not critical
for treatment purposes. Treatment decisions are based more
on symptomology than on virus type identiﬁcation but must be
initiated early in the disease course to be effective. From a
treatment standpoint, a rapid test that could identify the dis-
ease earliest after onset would be the best. This aspect was not
determined in this study.
In summary, the ZstatFlu-II test provides an alternative
rapid test technology for inﬂuenza virus types A and B which,
compared to culture, is more sensitive than Becton Dickinson’s
Directigen test and has the added advantage of providing a
permanent record of the test result. Chemiluminescence tech-
nology has the potential to increase the sensitivity of detection
systems used in rapid tests.
The clinical trial cost was defrayed by a grant from ZymeTx, Inc.
Development of the ZstatFlu-II test was funded in part by grants from
the Oklahoma Center for the Advancement of Science and Technol-
ogy (OCAST) awarded to C. D. Shimasaki (AR982-026) and to K. E.
Achyuthan (HN5-039 and AR021-004).
We gratefully acknowledge Don Mauchan, Paul Nangeroni, Dan
Mantell, Ed Gaffey, Paul Graham, and Leonard Aberbach (Polaroid
Corporation) for supplying the imaging devices and the Polaroid High-
Speed Detector Film. Stephen Simon (Children’s Mercy Hospital,
Kansas City, Mo.) helped with statistical analyses. Roberta Allen and
Robyn Cannedy provided technical assistance during the development
phase of the ZstatFlu-II test.
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