Comparison of direct immunofluorescence, immunoassays, and fecal flotation for detection of Cryptosporidium spp. and Giardia spp. in naturally exposed cats in 4 Northern California animal shelters.
BACKGROUND
Giardia spp. and Cryptosporidium spp. are common intestinal protozoan parasites in domestic cats. Few studies have critically evaluated the performance characteristics of commercially available immunoassays for detection of these organisms in the cat.


OBJECTIVE
Human-based immunoassays are suboptimal for the detection of Giardia spp. and Cryptosporidium spp. in cats.


METHODS
Three-hundred-and-forty-four cats with diarrheic and nondiarrheic fecal specimens at 4 northern California animal shelters.


METHODS
A fecal specimen was collected from each cat in a case-controlled fashion. Fecal specimens were tested for Giardia spp. and Cryptosporidium spp. by using centrifugation flotation and 5 commercially available immunoassays (SNAP Giardia, ProSpecT Giardia Microplate Assay, ProSpecT Cryptosporidium Microplate Assay, ImmunoCard STAT! Cryptosporidium/ Giardia Rapid Assay, and Xpect Giardia/Cryptosporidium). Results were compared with a reference standard, the MeriFluor direct immunofluorescence assay.


RESULTS
Overall prevalences of Giardia spp. and Cryptosporidium spp. were 9.8 and 4.7%, respectively. The ProSpecT Microplate Assay had the highest sensitivities and specificities for Giardia spp. (91.2 and 99.4%) and Cryptosporidum spp. (71.4 and 96.7%), respectively. The SNAP Giardia antigen assay was easier to use and equally sensitive (85.3%) and specific (100%) to fecal flotation.


CONCLUSIONS
Caution should be exercised when using human-based immunoassays for the diagnosis of Giardia and Cryptosporidium spp. in cats. Fecal flotation remains a useful method for detection of Giardia spp., can be used to detect other parasites, and has a sensitivity of 97.8% for detection of Giardia spp. when combined with the SNAP Giardia immunoassay.
Mekaru
Sumiko R
SR
Departments of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA.
Marks
Stanley L
SL
Felley
Allison J
AJ
Chouicha
Nadira
N
Kass
Philip H
PH
D000818:Animals; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D002371:Cat Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology*; D002415:Cats; D003457:Cryptosporidiosis / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D003458:Cryptosporidium / Q000302:isolation & purification*; D003967:Diarrhea / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary; D005243:Feces / Q000469:parasitology; D019085:Fluorescent Antibody Technique, Direct / Q000662:veterinary; D005872:Giardia / Q000302:isolation & purification*; D005873:Giardiasis / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D007118:Immunoassay / Q000662:veterinary; D010270:Parasite Egg Count / Q000662:veterinary; D015995:Prevalence; D012680:Sensitivity and Specificity; D015047:Zoonoses / Q000469:parasitology*