Previous Article | Next Article 
Journal of Clinical Microbiology, December 2001, p. 4523-4525, Vol. 39, No. 12
0095-1137/01/$04.00+0 DOI: 10.1128/JCM.39.12.4523-4525.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Evaluation of ColorPAC Giardia/Cryptosporidium
Rapid Assay and ProSpecT Giardia/Cryptosporidium
Microplate Assay for Detection of Giardia and
Cryptosporidium in Fecal Specimens
M. T.
Katanik,1
S. K.
Schneider,2
J. E.
Rosenblatt,2
G. S.
Hall,1 and
G. W.
Procop1,*
Section of Clinical Microbiology, Cleveland
Clinic Foundation, Cleveland, Ohio,1 and
Department of Clinical Microbiology, Mayo Clinic
Foundation, Rochester, Minnesota2
Received 27 June 2001/Returned for modification 7 August
2001/Accepted 17 September 2001
 |
ABSTRACT |
Detection of Giardia and
Cryptosporidium in clinical stool specimens using the
ColorPAC and ProSpecT enzyme immunoassays revealed 98.7% agreement for
Giardia detection and 98.1% agreement for Cryptosporidium detection. Sensitivities were uniformly
100%. The specificities of the ColorPAC immunoassay for
Giardia and Cryptosporidium detection
were 100 and 99.5%, respectively, and those for the ProSpecT assay
were 98.4 and 98.6%, respectively. The false-positive reactions with
the ProSpecT assay occurred with specimens that were grossly bloody.
 |
TEXT |
Giardia lamblia
is the most common intestinal parasite in the United States,
infecting approximately 2.5 million persons per year (1, 9, 15,
16). Infection with this organism, which usually occurs through
the ingestion of contaminated water, results in watery diarrhea,
abdominal cramps, and malabsorption that may last from weeks to months
(2, 18, 24, 30). Another important intestinal parasite,
particularly for patients with advanced AIDS, which may be transmitted
through contaminated water is Cryptosporidium parvum
(3, 5, 14, 19, 25). Although sporadic disease is more
common for these infections, both G. lamblia and C. parvum have also been shown to cause outbreaks involving day care
centers (24, 31).
The traditional method for the detection of these organisms is a
microscopic examination of stool preparations for the cysts and
trophozoites of Giardia and for the oocysts of
Cryptosporidium (12). This, however, requires a
considerable amount of time and a medical technologist who is
well-versed in the identification of fecal parasites (12, 13, 21,
22). Traditional methods may be insufficient to demonstrate the
presence of organisms and when used nonjudiciously are costly (4,
6, 8, 11, 12, 21, 22, 33). Fortunately, over the past decade a
variety of highly sensitive and specific enzyme immunoassays have been developed that detect the antigens of Giardia and
Cryptosporidium (7, 10-13, 17, 23, 26, 27-29,
31). These have become widely accepted as methods for screening
stools for the presence of Giardia and
Cryptosporidium (6, 20, 25, 32). We have evaluated two commercially available enzyme immunoassays, the ProSpecT Giardia/Cryptosporidium Microplate Assay
(Alexon-Trend, Inc., Ramsey, Minn.) and the ColorPAC
Giardia/Cryptosporidium Rapid Assay (Becton Dickinson,
Sparks, Md.), for the ability to detect G. lamblia and
C. parvum, in archived and routinely obtained clinical stool specimens.
Archived and routinely obtained clinical stool specimens fixed in 10%
formalin were tested using the ColorPAC
Giardia/Cryptosporidium Rapid Assay and the ProSpecT
Giardia/Cryptosporidium Microplate Assay. All of the
stool specimens tested were patient samples fixed in both 10% formalin
and polyvinyl alcohol; none of the specimens were spiked with
organism. Two hundred and forty-one stool specimens were tested for the
presence of G. lamblia and C. parvum. Forty-seven
of the stool specimens tested were archived. The archived specimens
were not more than 5 months from the date of collection. Tests were
performed according to the manufacturers' guidelines. Stools were
judged to contain the organism in question if both enzyme immunoassays
(EIAs) were positive, or if one EIA was positive and a subsequent
morphological examination revealed that organism. Stools were
considered truly negative if both EIAs were negative, or if one EIA was
negative and the subsequent morphological examination failed to reveal
the organism in question. Modified trichrome-stained smears of
polyvinyl alcohol-preserved stool and iodine wet preps from
ethyl-acetate- or formalin-concentrated stools collected in 10%
formalin were used to detect the cysts and trophozoites of
G. lamblia, while a modified Ziehl-Neelsen stain from
concentrated stool specimens was used to detect the oocysts of
C. parvum (12). Microscopic examinations of the
stool specimens were only performed if the EIAs were discrepant.
The results of testing are summarized in Tables
1 and 2.
Fifty-three of the 241 stool specimens were positive by both
assays for the presence of Giardia. Three stool
specimens were positive by ProSpecT assay but negative by the ColorPAC
assay; the morphological examination of these stools failed to reveal
Giardia. One hundred and eighty-five of 241 specimens
were negative for Giardia by both EIA methods. Nineteen
of the 241 stool specimens were positive by both methods for the
presence of Cryptosporidium. Three stool specimens were
positive by ProSpecT assay but negative by the ColorPAC assay; these
were the same three stool specimens that were positive for
Giardia by the ProSpecT assay but negative by the
ColorPAC assay. A single specimen was positive by the ColorPAC assay
but negative by the ProSpecT assay. None of the specimens with
discrepant EIA results were seen to contain Cryptosporidium upon morphological exam. The remaining specimens were negative for
Cryptosporidium by both EIAs. None of the archived specimens were discrepant. All the assays demonstrated 100% sensitivity. The
specificity of the ColorPAC assay was 100% for Giardia
and 99.5% for Cryptosporidium. The specificity of the
ProSpecT Giardia/Cryptosporidium assay was 98.4% for
Giardia and 98.6% for Cryptosporidium.
View this table:
[in this window]
[in a new window]
|
TABLE 1.
Performance of the ColorPAC
Giardia/Cryptosporidum Rapid Assay and of the
Giardia/Cryptosporidium Microplate Assay
|
|
View this table:
[in this window]
[in a new window]
|
TABLE 2.
Sensitivities and specificities of the ColorPAC
Giardia/Cryptosporidum Rapid Assay and of the
Giardia/ Cryptosporidium Microplate Assay
|
|
In this study, we evaluated the ability of two commercially available
assays, the ColorPAC Giardia/Cryptosporidium Rapid Assay and the ProSpecT Giardia/Cryptosporidium Microplate
Assay, to detect the presence of Giardia and/or
Cryptosporidium in archived and routine clinical stool
specimens. We found the ProSpecT and ColorPAC enzyme immunoassays
comparable, with 98.7% agreement for Giardia detection
and 98.1% agreement for Cryptosporidium detection. Both
assays were highly sensitive and specific. The reason for the
false-positive reactions is uncertain. However, it was noted that all
the specimens that generated false-positive results with the ProSpecT
Giardia/Cryptosporidium Microplate Assay were grossly
bloody; the blood was confirmed by microscopic examination of the
formalin-fixed specimen. The fact that these specimens were bloody was
merely an observation; the total number of blood specimens was not
recorded, as that was not the goal of this study. The effect of gross
blood in the stool on this assay requires further investigation. In our
opinion, although a time study was not performed, the ColorPAC EIA was
simpler to use, with faster time-to-results than with the ProSpecT
assay, similar to that reported previously (13). For
positive specimens, this was primarily because the ColorPAC EIA has
individual lines of identity, one for Giardia and one
for Cryptosporidium, while the ProSpecT combination Giardia/Cryptosporidium assay requires supplemental
testing to determine which organism is responsible for the positivity.
The ColorPAC EIA, however, is more expensive than the ProSpecT assay, based on manufacturer's retail price.
 |
FOOTNOTES |
*
Corresponding author. Mailing address: Department of
Pathology, Mailstop L40, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195. Phone: (216) 444-5879. Fax: (216) 445-6984. E-mail: procopg{at}ccf.org.
 |
REFERENCES |
| 1.
|
Addiss, D. G.,
H. M. Mathews,
J. M. Stewart, et al.
1991.
Evaluation of a commercially available enzyme-linked immunosorbent assay for Giardia lamblia antigen in stool.
J. Clin. Microbiol.
29:1137-1142[Abstract/Free Full Text].
|
| 2.
|
Addiss, D. G.,
J. P. Davis,
J. M. Roberts, and E. E. Mast.
1992.
Epidemiology of giardiasis in Wisconsin: increasing incidence of reported cases and unexplained seasonal trends.
Am. J. Trop. Med. Hyg.
47:13-19.
|
| 3.
|
Atherton, F.,
C. P. Newman, and D. P. Casemore.
1995.
An outbreak of waterborne cryptosporidiosis associated with a public water supply in the UK.
Epidemiol. Infect.
115:123-131[Medline].
|
| 4.
|
Chappell, C. L.,
P. C. Okhuysen,
C. R. Sterling,
C. Wang,
W. Jakubowski, and H. L. DuPont.
1999.
Infectivity of Cryptosporidium parvum in healthy adults with pre-existing anti-C. parvum serum immunoglobulin G.
Am. J. Trop. Med. Hyg.
60:157-164[Abstract].
|
| 5.
|
Colford, J. M., Jr.,
I. B. Tager,
A. M. Hirozawa,
G. F. Lemp,
T. Aragon, and C. Petersen.
1996.
Cryptosporidiosis among patients infected with human immunodeficiency virus. Factors related to symptomatic infection and survival.
Am. J. Epidemiol.
144:807-816[Abstract/Free Full Text].
|
| 6.
|
Current, W. L., and L. S. Garcia.
1991.
Cryptosporidiosis.
Clin. Microbiol. Rev.
3:325-358.
|
| 7.
|
Doing, K. M.,
J. L. Hamm,
J. A. Jellison,
J. A. Marquis, and C. Kingsbury.
1999.
False-positive results obtained with the Alexon ProSpecT Cryptosporidium enzyme immunoassay.
J. Clin. Microbiol.
37:1582-1583[Abstract/Free Full Text].
|
| 8.
|
DuPont, H. L.,
C. L. Chappell,
C. R. Sterling,
P. C. Okhuysen,
J. B. Rose, and W. Jakubowski.
1995.
The infectivity of Cryptosporidium parvum in healthy volunteers.
N. Engl. J. Med.
332:855-859[Abstract/Free Full Text].
|
| 9.
|
Furness, B. W.,
M. J. Beach, and J. M. Roberts.
2000.
Giardiasis surveillance United States 1992-1997.
Morb. Mortal. Wkly. Rep.
49:1-13[Medline].
|
| 10.
|
Garcia, L. S., and R. Y. Shimizu.
1997.
Evaluation of nine immunoassay kits (enzyme immunoassay and direct fluorescence) for the detection of Giardia lamblia and Cryptosporidium parvum in human fecal specimens.
J. Clin. Microbiol.
35:1526-1529[Abstract].
|
| 11.
|
Garcia, L. S.,
A. C. Shum, and D. A. Bruckner.
1992.
Evaluation of a new monoclonal antibody combination reagent for direct fluorescent detection of Giardia cysts and Cryptosporidium oocysts in human fecal specimens.
J. Clin. Microbiol.
30:3255-3257[Abstract/Free Full Text].
|
| 12.
|
Garcia, L. S., and D. A. Bruckner.
1997.
Diagnostic medical parasitology, 3rd ed.
ASM Press, Washington, D.C.
|
| 13.
|
Garcia, L. S., and R. Y. Shimizu.
2000.
Detection of Giardia lamblia and Cryptosporidium parvum antigens in human fecal specimens, using the ColorPAC Combination rapid solid-phase qualitative immunochromographic assay.
J. Clin. Microbiol.
38:1267-1268[Abstract/Free Full Text].
|
| 14.
|
Inungu, J. N.,
A. A. Morse, and C. Gordon.
2000.
Risk factors, seasonality, and trends of cryptosporidiosis among patients infected with human immunodeficiency virus.
Am. J. Trop. Med. Hyg.
62:384-387[Abstract].
|
| 15.
|
Kappus, K. D.,
D. D. Juranek, and J. M. Roberts.
1991.
Results of testing for intestinal parasites by state diagnostic laboratories United States, 1987.
Morb. Mortal. Wkly. Rep.
40:25-47.
|
| 16.
|
Kappus, K. D.,
R. G. Lundgren,
D. D. Juranek, et al.
1994.
Intestinal parasitism in the United States. update on a continuing problem.
Am. J. Trop. Med. Hyg.
50:705-713.
|
| 17.
|
Kehl, K. C.,
H. Cicirello, and P. L. Havens.
1995.
Comparison of four different methods for the detection of Cryptosporidium species.
J. Clin. Microbiol.
33:416-418[Abstract].
|
| 18.
|
Kramer, M. H.,
B. L. Herwaldt,
G. F. Craun,
R. L. Calderon, and D. D. Juranek.
1996.
Surveillance for waterborne-disease outbreaks United States, 1993-1994.
Morb. Mortal. Wkly. Rep.
45:1-33[Medline].
|
| 19.
|
Mackenzie, W. R.,
N. J. Hoxie, and M. E. Proctor.
1994.
A massive outbreak in Milwaukee of Cryptosporidium infection transmitted through the public water supply.
N. Engl. J. Med.
331:161-167[Abstract/Free Full Text].
|
| 20.
|
Marshall, M. M.,
D. Naumovitz,
Y. Ortega, and C. R. Sterling.
1997.
Waterborne protozoan pathogens.
Clin. Microbiol. Rev.
10:67-85[Abstract].
|
| 21.
|
Morris, A. J.,
M. L. Wilson, and L. B. Reller.
1992.
Application of rejection criteria for stool ovum and parasite examinations.
J. Clin. Microbiol.
30:3213-3216[Abstract/Free Full Text].
|
| 22.
|
Morris, A. J.,
P. R. Murray, and L. B. Reller.
1996.
Contemporary testing for enteric pathogens: the potential for cost, time, and health care savings.
J. Clin. Microbiol.
34:1776-1778[Abstract].
|
| 23.
|
Nash, T. E.,
D. A. Herrington, and M. M. Levine.
1987.
Usefulness of an enzyme-linked immunosorbent assay for detection of Giardia antigen in feces.
J. Clin. Microbiol.
25:1169-1171[Abstract/Free Full Text].
|
| 24.
|
Ortega, Y. R., and R. D. Adam.
1997.
Giardia: overview and update.
Clin. Infect. Dis.
25:545-550[Medline].
|
| 25.
|
Pieniazek, N. J.,
F. J. Bornay-Llinares,
S. B. Slemenda,
A. J. da Silva,
I. N. S. Moura,
M. J. Arrowood,
O. Ditrich, and D. G. Addis.
1999.
New Cryptosporidium genotypes in HIV-infected persons.
Emerg. Infect. Dis.
5:444-449[Medline].
|
| 26.
|
Priest, J. W.,
J. P. Kwon,
D. M. Moss,
J. M. Roberts,
M. J. Arrowood,
M. S. Dworkin,
D. D. Juranek, and P. J. Lammie.
1999.
Detection of enzyme immunoassay of serum immunoglobulin G antibodies that recognize specific Cryptosporidium parvum antigens.
J. Clin. Microbiol.
37:1385-1392[Abstract/Free Full Text].
|
| 27.
|
Rosenblatt, J. E., and L. M. Sloan.
1993.
Evaluation of an enzyme-linked immunosorbent assay for detection of Cryptosporidium spp. in stool specimens.
J. Clin. Microbiol.
31:1468-1471[Abstract/Free Full Text].
|
| 28.
|
Rosenblatt, J. E.,
L. M. Sloan, and S. K. Schneider.
1993.
Evaluation of an enzyme-linked immunosorbent assay for the detection of Giardia lamblia in stool specimens.
Diagn. Microbiol. Infect. Dis.
16:337-341[CrossRef][Medline].
|
| 29.
|
Rosoff, J. D.,
C. A. Sanders,
S. S. Sonnad,
P. R. De Lay,
W. K. Hadley,
F. F. Vincenzi,
D. M. Yajko, and P. D. O'Hanley.
1989.
Stool diagnosis of giardiasis using a commercially available enzyme immunoassay to detect Giardia-specific antigen 65 (GSA 65).
J. Clin. Microbiol.
27:1997-2002[Abstract/Free Full Text].
|
| 30.
|
Steiner, T. S.,
N. M. Theilman, and R. L. Guerrant.
1997.
Protozoal agents: what are the dangers for the public water supply?
Annu. Rev. Med.
48:329-340[CrossRef][Medline].
|
| 31.
|
Tangermann, R. H.,
S. Gordon,
P. Wiesner, and L. Kreckman.
1991.
An outbreak of cryptosporidiosis in a day-care center in Georgia.
Am. J. Epidemiol.
133:471-476[Abstract/Free Full Text].
|
| 32.
|
Wolfe, M. S.
1992.
Giardiasis.
Clin. Microbiol. Rev.
5:93-100[Abstract/Free Full Text].
|
| 33.
|
Zimmerman, S. K., and C. A. Needham.
1995.
Comparison of conventional stool concentration and preserved-smear methods with Merifluor Cryptosporidium/Giardia direct immunofluorescence assay and ProSpecT Giardia EZ microplate assay for detection of Giardia lamblia.
J. Clin. Microbiol.
33:1942-1943[Abstract].
|
Journal of Clinical Microbiology, December 2001, p. 4523-4525, Vol. 39, No. 12
0095-1137/01/$04.00+0 DOI: 10.1128/JCM.39.12.4523-4525.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Youn, S., Kabir, M., Haque, R., Petri, W. A. Jr.
(2009). Evaluation of a Screening Test for Detection of Giardia and Cryptosporidium Parasites. J. Clin. Microbiol.
47: 451-452
[Abstract]
[Full Text]
-
Garcia, L. S., Garcia, J. P.
(2006). Detection of Giardia lamblia Antigens in Human Fecal Specimens by a Solid-Phase Qualitative Immunochromatographic Assay. J. Clin. Microbiol.
44: 4587-4588
[Abstract]
[Full Text]
-
Guy, R. A., Xiao, C., Horgen, P. A.
(2004). Real-Time PCR Assay for Detection and Genotype Differentiation of Giardia lamblia in Stool Specimens. J. Clin. Microbiol.
42: 3317-3320
[Abstract]
[Full Text]