Note: Descriptions are shown in the official language in which they were submitted.
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DIAGNOSTIC-TEST SPECIM~N-PREPARATION VIAL
Technical Field
-
The present invention relates to a vial for use in
preparing specimens for diagnostic tests such as medical
tests for detecting certain viruses in fecal matter or other
clinical specimens.
Background Art
Gastroentestinal diseases are among the most
prevalent types of illness in infants and young children.
Only recently have specific virus infections been identified
as a major cause of many of these diseases.
One virus, a rotavirus, has been identified as a
principal cause of sporadic acute winter gastroenteritis in
infants and young children. Children who contract this
infection frequently suffer from severe diarrhea and fever,
3~ occasionally accompanied by vomiting. In severe cases, the
disease can be fatal. It has been estimated that about half
of the infants treated for acute winter gastroenteritis are
suffering from a gastroenteritis caused by this virus. The
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disease is a world-wide problem and is a significant cause of
childhood deaths in developing countries.
Diagnosis of gastroenteritis caused by a rotaviral
infection is based on the presence of rotavirus particles in
the feces. Rotavirus particles are generally shed in large
quantities during gastroentestinal rotaviral infections.
Rotavirus par~icles are too small to be observed directly
~ith an optical microscope. However, the characteristically
wheel-shaped particles can be observed with an electron
microscope. In addition, rotavirus particles can be
identified by a number of immunochemical diagnostic
procedures, including latex-bound-antibody agglutination,
immunofluorescence, and enzyme-linked immunosorbent assay
~5 techniques.
Typically, diagnostic procedures for detecting the
presence of rotavirus particles in fecal matter involve a
number of preliminary specimen preparations steps which have
heretofore been a source of troublesome problems. Ordinarily
a specimen of fecal matter must be collected from a soiled
diaper or bedpan of an afflicted person using a disposable
spatula and transferred to a specimen-container for transport
to a clinical laboratory. In the laboratory the specimen is
usually mixed with a buffer solu~ion to disperse the fecal
matter and any virus particles which may be present in the
solution. The mixing step is often carried out in the
specimen container used to transport the specimen to the
laboratory or in a laboratory beaker. Many te~t procedures
further require that any gross debris in the solution of
fecal matter be removed. Such gross debris is often removed
by centrifugation, in which case the solution must be
transferred to a centrifuge tube and spun in a centrifuge.
The supernatant liquid in the centrifuge tube is then used to
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~25~L7~6
prepare slides for examination with an electron microscope or
used in an immunochemical diagnostic test procedure.
The conventional specimen-preparation procedure
described above has a number of significant drawbacks. The
procedure generally involves transferring fecal material or
solutions containing fecal material from container to
container, which is unpleasant for nursing and laboratory
personnel and carries a risk of contamination and infection.
Furthermore, the various implements and containers involved
must be disposed of or cleaned and sterilized for reuse. The
supernatant liquid obtained in the centrifugation step
generally includes bacteria or parasitic organisms from the
fecal material in addition to whatever virus particles are
present. In certain immunochemical diagnostic test
procedures for rotaviruses, certain bacteria or other non-
viral microorganisms which are occasionally present in fecal
matter can interact with the test reagents to give rise to
ambiguous or even erroneous test resultsO
International patent application No. PCT/BR82/00013
published under International Publication No. WO 83/01194 on
April 14, 1983 by the World Intellectual Property
Organization (the '194 publication) discloses a disposable
container for collecting a specimen of fecal matter and
preparing it for parasitological examination. The container
includes a semiflexible specimen-receiver vessel in which a
specimen of fecal matter can be diluted with water or other
diluent. The container includes a cover which can be screwed
on the specimen-receiver vessel. The cover has an opening
passing through it from which samples of diluted fecal matter
can be expelled for parasitological analysis by squeezing the
sides of the specimen-receiver vessel. A plug is provided
for sealing the opening in the cover. A seive is fitted
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~.2S~7~6
within the cover for straining the solution of fecal matter
withdrawn from the container. The orifices of the seive have
dimensions which permit the seive to serve in place of gauze
or nets of wire or plastic which are used to strain diluted
fecal matter in conventional parasitological analysis
procedures. Essential in this straining i5 to let, for
instance, the parasitic ova to flotate through the sieve. A
specimen-collector stick is attached to the seive for
collecting specimens of fecal matter and introducing them
into the specimen-receiver vessel.
The container of the '194 publication would have
substantial drawbacks were the container to be used to
prepare a specimen of fecal matter for testing for the
presence of rotavirus. For example, dispersed in the
solution of fecal matter expelled from the container of the
'194 publication along with whatever virus particles are
present can be bacteria and other non-viral microorganisms,
as well as gross particles such as certain intestinal
parasites and the eggs of such parasites. Bacteria and non-
viral microorganisms are small enough to pass through gauze
or net strainers used in parasitological examination
procedures, and thus would pass through the seive of the
container of the '194 publication. As noted above, the
presence of such bacteria or non-viral microorganisms can in
certain cases interfere with immunochemical diagnostic test
procedures for rotavirus.
Disclosure of the Invention
We have invented a specimen-preparation vial for
collecting and preparing a clinical specimen such as a
specimen of fecal matter for a diagnostic test which avoids
problems of the prior art noted above.
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Broadly, the specimen-preparation vial of the
invention comprises a specimen-dilution container and a
specimen collection/dispenser top for the container.
The specimen-dilution container i5 shaped to
contain a liquid in an interior volume and has an opening
dimensioned to permit the speci~en to be introduced into the
interior volume. A sidewall of the container is yieldable
upon manual squeezing.
The specimen-collection/dispenser top also includes
a specimen-collection tool connected to the cap housing. The
specimen-collection tool projects from the cap housing so
that the tool extends into the interior volume of the
specimen-dilution container when the opening of the container
is closed by the cap housing.
The specimen-collection/dispenser top further
includes a dispenser tip and a dispenser-tip closure. The
dispenser tip is connected to the cap housing. The dispenser
tip has a channel passing through it. An end of the channel
defines a filtrate-discharge orifice of the dispenser ~ip.
The channel through the dispenser tip communicates with the
interior volume of the specimen-dilution container when the
opening of the container is closed by the cap housing~ The
dispenser-tip closure is adapted to close the filtrate-
discharge orifice of the channel passing through the
dispenser tip.
The specimen-collection/dispenser top further
includes a microfiltration filter located in the cap housing
in a liquid path which extends from the interior volume of
the specimen-dilution container to the filtrate-discharge
orifice so that liquid which flows from the interior vclume
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of the container to the filtrate discharge orifice passes
through the microfiltration filter. The microfiltration
filter has pores passing through it of dimensions effective
to permit virus particles to pass through the pores and to
block the passage of particles significantly larger than
virus particles, such as bacteria cells. Thus by squeezing
the sides of the specimen-dilution container a user can
dispense a filtered extract of the specimen in the container,
which extract can contain virus particles but which is
substantially free of bacteria, other non-viral
microorganisms, fatty material, and gross debris.
For use in connection with diagnostic test for
rotaviruses, the microfiltration filter of the specimen-
preparation vial of the invention preferably has pores of
dimensions effective to pass particles having crosswise
dimensions of about l-lOum or less and to block particles
- having crosswise dimension greater than about l-lOum. The
microfiltration filter may be of a woven or nonwoven fabric
of cotton, rayon or other fiber or filament. If desired, the
microfiltration filter may be made of porous ceramic,
charcoal, reticulated foam, sintered beads, or other porous
material having pores of the appropriate dimensions. If
desired, the microfiltration filter may be impregnated with a
reagent material such as antibodies or antigens.
Microfiltration filters made of a fabric are prone
to shift or wrinkle. Such fabric microfiltration filters are
preferably spatially separated by a fabric nonwoven mesh of
monofilament nylon to inhibit shifting and wrinkling of the
microfiltration filters.
L25~7~L6
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The specimen-collection tool of the sample-
preparation vial of the invention is preferably of a
generally flat shape having a depression in one end forming a
spoon blade. Such a spoon blade can be used to collect
specimens of either solid or runny fecal material.
Alternati~ely, the specimen-collection tool could be a flat
paddle, a capillary tube, or an absorbent swab.
The dispenser-tip closure of the specimen-
collection/dispenser top of the specimen-preparation vial of
the invention is preferably a break-away-tab plug seal. The
cap-housing, dispenser tip and break-away-tab plug seal are
preferably molded as a unitary structure. The ~oint
connecting the break-away-tab plug seal ~o the end of the
dispenser tip is made sufficiently thin to permit the plug
seal to be broken away readily. Breaking the plug seal away
from the dispenser tip opens the filtrate-discharge orifice
of the dispenser tip. The break-away-tab plug seal is
preferably shaped so that, once broken off from the dispenser
tip, it can be inserted in the filtrate-discharge orifice.
Alternatively, the dispenser-top-closure of the
specimen-collection/dispenser top may be a snap-on or screw-
on cap or an on-off valve mechanism.
The dispenser tip preferably has a generally
conical shape to facilitate dispensing the fil~rate liquid
drop-by-drop. The filtrate-discharge orifice preferably has
an inside diameter ~hich is effective to cause the orifice to
dispense the filtrate liquid in drops of a volume appropriate
for the diagnostic test procedure in which the filtrate is to
be used.
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The sample-preparation vial of the present
invention is inexpensive to manufacture and can be discarded
after a single use. The vial can be marketed prefilled with
a test reagent such as a buffer solution sui~able for
diluting a specimen in a particular diagnostic test.
The sample preparation vial of the present
invention can be used to advantage in a number of diagnostic
tests which require extracts of clinical specimens which are
substantially free of bacteria, non-viral microorganisms,
fatty material, and gross debris. The sample-preparation
vial is particularly suited for use in tests for detecting
the presence of rotavirus in specimens of fecal matter,
including immunochemical diagnostic tests such as latex-
bound-antibody agglutination, immunofluorescence, and
enzyme-linked immunosorbent assay techniques, as well as
electron microscopy analytical procedures. A preferred
sample-preparation vial of the present invention was found to
eliminate over 90 percent of the bacteria in a solution of
fecal matter. Use of the sample-preparation vial of the
invention to prepare a filtered extracts of fecal matter for
testing was found to improve significantly the sensitivity
and specificity of a latex-bound-antibody agglutination test
for the presence of rotavirus in the fecal ma~ter.
Brief DescriPtion of the Drawin~s
Preferred embodiments of the invention are
described below with reference to the following drawings.
FIG. l is a partially cut away front view of a
preferred specimen-preparation vial of the present invention
with the specimen collection/dispenser top disconnected from
the specimen-dilution container.
g ~LZ5~716
FIG. 2 is a partially-exploded cross-sectional view
taken along line 2-2 of FIG. l.
FIG. 3 is a cross-sectional view taken along line
3-3 of FIG. 2.
FIG. 4 is a front view of a spoon member of the
cpecimen-preparation vial of FIG. l.
FIG. 5 is a top view of the spoon member of FIG. 4.
Description of the Preferred Embodiments
Re~erring now to FIG. l, a specimen preparation
vial lO of the present invention comprises a unitary
specimen-dilution container 20 and a specimen
collection/dispenser top 50.
The specimen-dilution container 20 is a generally
cylindrically-shaped vessel molded from polypropylene. The
container 20 has a sidewall 30 which is sufficiently thin to
yield readily when squeezed by a user, so that, as described
below, liquid in the container 20 can be dispensed drop-by-
drop by squeezing the sides of the container. The container
20 has an opening 34 which is sufficiently wide in diameter
to permit a specimen of fecal matter roughly one ml in volume
to be inserted in the container. A neck 40 of the specimen-
dilution container 20 is threaded with threads 41 to psrmit
the specimen-collection/dispenser top S0 to be screwed on.
As shown best in FIG. 2, the specimen
collection/dispenser top 50 comprises a dispenser cap llO, a
specimen-collection spoon member 130, and a filter assembly
150.
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The dispenser cap 110 is a unitary structure molded
of polystyrene. The dispenser cap 110 includes a generally
conical dispenser tip 112 having a filtrate-di~penser
passageway 115 extending through it. A break-away-tab plug
seal 160 has a plug shaft 162 and a tab grip 164. The plug
shaft 162 is breakably connected to a filtrate discharge end
of the dispenser tip 112 by a breaka~le joint 165. The plug
shaft 162 closes off and seals the filtrate-dispenser
passageway 115. The break-away-tab plug seal 1~0 can be
detached from the dispenser tip 112 by breaking the plug
shaft 162 at the breakable joint 165. Once the plug shaft
162 is broken away, a filtrate-discharge orifice 111 is
opened in the dispenser tip 112. Liquid can pass from the
filtrate-dispenser passageway 115 through the filtrate-
discharge orifice 111 and be dispensed drop-by-drop from the
dispenser tip 112. The inside diameter of the filtrate-
discharge orifice 111 is selected so that the drops of liquid
formed on the dispenser tip 112 have a volume appropriate for
the diagnostic procedure in which the drops are to be used.
After the break-tab plug seal 160 has been broken away from
the dispenser tip, the plug shaft 162 can be inserted in the
filtrate discharge orifice 111 to plug the orifice.
The dispenser cap 110 includes a filter-holder
cylinder 118 and a cap-sidewall cylinder 124. The diameter
of the cap-sidewall cylinder 124 is larger than the diameter
of the filter-holder cylinder 118. The two cylinders 118 and
124 are disposed generally coaxially with respect to one
another with the filter-holder cylinder 118 extending from a
point within the cap-sidewall cylinder 124 to a point beyond
the end of the cap-sidewall cylinder 124. ~n annular
container sealing rim 120 connects an end of the cap-sidewall
cylinder 124 to a central section of the filter-holder
cylinder 118.
2s~716
A generally-conical, annular filter-support rim 113
extends between a base of the dispenser tip 112 and the
filter-holder sidewall 118. As may be seen in FIG. 3, eight
filter-support ribs 11~ extend generally radially from a
central opening 116 of the filter-support rim 113 to an outer
perimeter of the rim on the side of the rim facing away from
the dispenser tip 112. The filter-support ribs 114 are
spaced apart from one another azimuthally at approximately
equiangular intervals about the central opening 116 in the
~ilter-support rim 113.
Four filter-assembly-retainer tabs 122 project
radially inwardly from an inside surface o~ the filter-holder
cylinder 118. The filter-assembly-retainer tabs 122 are
spaced apart azimuthally from one another at approximately
ninety-degree intervals about the inside surface of the
filter-holder cylinder 118 and are spaced apart axially from
.the filter support ribs 114 by a filter-assembly retainer
distance.
The cap-sidewall cylinder 124 of the dispenser cap
110 is threaded on its inside surface to engage the screw
threads 41 on the nec~ 40 of the specimen-dilution container
20. The pitch of the screw threads is sufficiently high to
permit the specimen-collection/dispenser top 50 to be screwed
on or off the specimen-dilution container 20 in approximately
one full rotation. An annular gap between an outer surface
of the filter-holder cylinder 118 and an inner surface of the
cap-sidewall cylinder 124 defines a container-sealing gap
123. The container-sealing gap 123 is dimensioned to receive
and tightly seal a rim around the opening 3~ of the
specimen-dilution container 20 when the specimen
collection/dispenser top 50 is screwed on the specimen
dilution container 20.
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Turning now to FIGS. 4 and 5, the specimen-
collection spoon member 130 comprises a spoon support base
131 and a specimen-collection spoon 140. The spoon support
base 131 comprises an annular filter-assembly-retainer rim
132 and first and second cross members 134 and 136 extending
across the rim 132. The filter-assembly-retainer rim 132 is
dimensioned to fit tightly within the filter-holder cylinder
118 and to engage the filter-assembly-retainer tabs 122.
1~ When the specimen-collection/dispenser top 50 is
assembled, the filter assembly 150 is located between the
filter-support ribs 114 and the spoon-support base 131. The
cross members 134 and 136 of the spoon-~upport base 131 have
approximately the same width as the width of the filter-
assembly-retainer rim 132 and divide the area inside the rim
into four quadrants with an opening 137 in each quadrant. As
a result of this arrangement, the spoon-support base 131
supports the filter assembly 15~ ~hile permitting liquid to
pass through the openings between the cross members 134 and
136. When the filter-assembly-retainer rim 132 engages the
filter-assembly-retainer tabs 122, the spoon-support base 131
holds the filter assembly 150 tightly agains~ filter-support
ribs 114, with the retainer rim 132 tending to prevent liquid
from flowing around the perimeter of the filter assembly 150
and thereby bypassing the filter.
The specimen-collection spoon 140 of the spoon
member 130 is attached ~o the cross member 136 of the spoon-
support base 131. The specimen collection spoon 146
comprises a generally flat spoon shaft 144 which has a
depression in a first end to define a spoon blade 146. A
second end 142 of the spoon shaft 144 is connected to the
cross member 136. The entire spoon member 130 is molded from
polypropylene. As shown in FIG. 4, the spoon shaft 144 is
,
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tapered slightly in a crosswise dimension. In addition, the
spoon shaft 144 is flared at its second end 142 in order to
strengthen the joint between the shaft and the cross member
136.
The spoon blade 146 can be used to collect a
specimen of fecal matter for diagnosis for rotavirus. With
the spoon member 130 held in place in the top 50, the spoon
shaft 144 projects ax;ally beyond the end of the cap-sidewall
cylinder 124. The cap-sidewall cylinder 124 can be used as a
handle for manipulating the spoon member 130, thereby
facilitating the collection of a specimen of fecal matter for
diagnosis. The shape of the spoon blade 146 permits
specimens to be collected from either solid or runny fecal
material.
Turning again to FIG. 2, the filter assembly 150
includes a nylon mesh filter 152 sandwiched between a first
and a second microfitration filter 154 and 156. The filter
assembly 150 is located adjacent to the filter-support ribs
114 so that the filter is spaced away from the filter-support
rim 113. Spaces between the filter support ribs 114 form
channels through which filtrate can flow from the filter into
the central opening 116 of the filter-support rim 113.
The microfiltration filters 154 and 156 are made of
a porous blotting paper like felt or glas~ fiber material
which act as a conventional depth filter retaining
microorganisms and particles larger than viruses. In
particular, the pores of the microfiltration filters 154 and
156 tend to pass particles having effective crosswise
dimensions of less than about l-lOum and to block particles
having greater crosswise dimensions. Consequently, rotavirus
particles generally pass through the filter unit while non-
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~LZ5~7il~;
virus microorganisms typically found in fecal matter
generally do not. The filter support net 152 is made of a
nonwoven monofilament nylon material. The filter support net
tends to prevent the microfiltration filters 154 and 156 from
drifting together and becoming obstructed. A sitable
support net sandwiched between two layers of microfilters has
a pore size of about 53um and is commercially available under
the trade designation ~CMN53" from Small Parts Inc. of Miami,
Florida.
The diagnostic-test specimen-preparation vial 10
can be used to advantage to prepare a filtered extract of
fecal matter for a latex-bound-antibody agglutination test
for the presence of rotavirus in the fecal matter. The use
of the specimen-preparation vial will be described below in
terms of carrying out such a test procedure, although it will
be appreciated that the specimen-preparation vial can be used
to similar advantage in other clinical test pro~edures for
virus particles.
Approximately 10 ml of a pH 7.2 buffer solution
containing about 0.1 percent sodium azide as a perservative
is introduced into the specimen-dilution contained 20. A
suitable buffer solution is commercially available under the
trade name "Rotalex ~uffer" from Orion Diagnostica of Espoo,
Finland.
The buffer solution may be sealed in the sample-
preparation vial 10 for storage for an extended period prior
to use by screwing the top 50 on the specimen-dilution
container 20 with the break-away-tab plug seal 160 in place.
It is anticipated that the specimen-preparation vial of the
invention will ordinarily be sold to users prefilled with an
-1 5- ~ 25~7~6
appropriate quantity of buffer solution for a single
diagnostic test procedure.
To test for the presence of rotavirus in the stools
of a patien~, the specimen collection/dispenser top 50 is
removed from the specimen-dilution container 20. The
specimen-collection spoon member 130 is used to collect a
specimen of fecal matter (e.g. one ml in volume) from the
stools of the patient. The spoon member 130 containing the
specimen is ~hen reinserted into the specimen-dilution
container 20 and the top 50 is ~hreaded onto the container 20
to seal the container. The specimen preparation vial 10 is
then shaken vigorously in order to mix the fecal matter and
buffer solution thoroughly and thereby disperse the
rotavirus, if present, in the buffer solution.
Next, the break-away-tab plug seal 160 is broken
off from the dispenser tip 112. The specimen-preparation
vial 10 is then inverted and the sides of the specimen-
dilution container 20 are gently squeezed. The squeezing of
the container 20 forces the solution of fecal matter against
the filter assembly 150 and causes a filtrate of filtered
fecal extract solution to pass though the filter assembly and
flow down the filtrate-dispenser passageway llS to the
25 filtrate-discharge orifice 111 in the dispenser tip 112.
Filtered fecal extract solution is then dispensed drop-by-
drop from the filtrate discharge orifice 111 of the dispenser
tip 112 by squeezing the sides of the specimen-dilution
container 20. The filtered fecal-extract solution is
substantially free of bacteria and gross debris, but contains
rotavirus particles if the solution of fecal matter in the
specimen-dilution container 20 contains rotavirus particles.
-16- ~25~6
The first 10-20 drops of filtered fecal extract
solution are discarded. The next two drops are placed
respectively on two separate areas of a black, nonabsorbent
card. One drop of a rotavirus-sensitive agglutination test
reagent is applied to one of the drops of filtered fecal-
extract solution on the card and one drop of a nega~ive
control reagent is applied to the other drop of filtered
fecal-extract solution. The test reagent is a suspension of
latex particles to which ~abbit anti-rotavirus antibodies are
bound in a medium which contains about 0.1 percent sodium
azide as a preservative. ~ suitable test reagent is
commercially available under the trade name "Rotalex Test
Latex Reagent" from Orion Diagnostica identified above. The
negative control reagent is a suspension of albumin bound to
latex particles in a medium which contains about 0~1 percent
sodium azide as a preservative. A suitable negatlve control
reagent is commerically available under the trade name
~Rotalex Non-Reactive Latex Reagent" from Orion Diagnostica.
Each of the two pairs of drops is then stirred gently using a
separate clean mixing paddle for each pair to avoid cross
mi~ing. The test card is then tilted and rotated for about
two minutes to cause the reagents to move in a circular
pattern. The presence of agglutination of latex particles in
the sample containing the test reagent and the absence of
agglutination in the sample containing the negative control
indicates that the fecal material contained rotavirus.
Following the test, the break-tab plug seal 160 can
be inserted in the filtrate-discharge orifice 111 of the
30 dispenser top 112 to seal the specimen preparation vial 10.
The vial thus sealed can then be discarded with a minimum
risk of spillage or infection of personnel administering the
test or contamination of the surrounding environment.
-l7- ~25~716
It is not intended to limit the present invention
to the specific embodiment described above. For example, the
cap housing can be connected to the specimen-dilution
container by a snap-on action. It is recognized that this
and other changes may be made in the specimen-preparation
vial specifically described herein without departing from the
scope and teaching of the instant invention, and it is
intended to encompass all other embodiments, alternatives and
modifications consistent with the invention.
3~
