This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Weber, R Articles by Juranek, D D Search for Related Content PubMed PubMed Citation Articles by Weber, R Articles by Juranek, D D

 Previous Article  |  Next Article 

J Clin Microbiol. 1992 November; 30(11): 2869-2873

Improved stool concentration procedure for detection of Cryptosporidium oocysts in fecal specimens.

Parasitic Diseases Branch, Centers for Disease Control, Atlanta, Georgia 30333.

ABSTRACT

Epidemiologic and laboratory data suggest that coprodiagnostic methods may fail to detect Cryptosporidium oocysts in stool specimens of infected patients. To improve the efficacy of stool concentration procedures, we modified different steps of the Formalin-ethyl acetate (FEA) stool concentration technique and evaluated these modifications by examining stool samples seeded with known numbers of Cryptosporidium oocysts. Because these modifications failed to improve oocyst detection, we developed a new stool concentration technique that includes FEA sedimentation followed by layering and flotation over hypertonic sodium chloride solution to separate parasites from stool debris. Compared with the standard FEA procedure, this technique improved Cryptosporidium oocyst detection. The sensitivities of the two concentration techniques were similar for diarrheal (watery) stool specimens (100% of watery stool specimens seeded with 5,000 oocysts per g of stool were identified as positive by the new technique, compared with 90% of stools processed by the standard FEA technique). However, the most significant improvement in diagnosis occurred with formed stool specimens that were not fatty; 70 to 90% of formed stool specimens seeded with 5,000 oocysts were identified as positive by the new technique, compared with 0% of specimens processed by the standard FEA technique. One hundred percent of formed specimens seeded with 10,000 oocysts were correctly diagnosed by using the new technique, while 0 to 60% of specimens processed by the standard FEA technique were found positive. Similarly, only 50 to 90% of stool specimens seeded with 50,000 oocysts were identified as positive by using the standard FEA technique, compared with a 100% positive rate by the new technique. The new stool concentration procedure provides enhanced detection of Cryptosporidium oocysts in all stool samples.

This article has been cited by other articles:

• Savin, C., Sarfati, C., Menotti, J., Jaouhari, J., Wurtzer, S., Garin, Y. J. F., Derouin, F. (2008). Assessment of Cryptodiag for Diagnosis of Cryptosporidiosis and Genotyping Cryptosporidium Species. J. Clin. Microbiol. 46: 2590-2594 [Abstract] [Full Text]  
• Bertrand, I., Albertini, L., Schwartzbrod, J. (2005). Comparison of Two Target Genes for Detection and Genotyping of Giardia lamblia in Human Feces by PCR and PCR-Restriction Fragment Length Polymorphism. J. Clin. Microbiol. 43: 5940-5944 [Abstract] [Full Text]  
• Atwill, E. R., Camargo, S. M., Phillips, R., Alonso, L. H., Tate, K. W., Jensen, W. A., Bennet, J., Little, S., Salmon, T. P. (2001). Quantitative Shedding of Two Genotypes of Cryptosporidium parvum in California Ground Squirrels (Spermophilus beecheyi). Appl. Environ. Microbiol. 67: 2840-2843 [Abstract] [Full Text]  
• Kuczynska, E., Shelton, D. R. (1999). Method for Detection and Enumeration of Cryptosporidium parvum Oocysts in Feces, Manures, and Soils. Appl. Environ. Microbiol. 65: 2820-2826 [Abstract] [Full Text]  
• Pereira, M. d. G. C., Atwill, E. R., Jones, T. (1999). Comparison of Sensitivity of Immunofluorescent Microscopy to That of a Combination of Immunofluorescent Microscopy and Immunomagnetic Separation for Detection of Cryptosporidium parvum Oocysts in Adult Bovine Feces. Appl. Environ. Microbiol. 65: 3236-3239 [Abstract] [Full Text]