Is multiple-stool-specimen ova and parasite examination necessary?

Abstract number: P982

Grünbaum F., Muñoz C., Morató R., Giménez E., Soler R., Llobet T., Coll P.

Objectives: We performed a retrospective analysis of 12,862 ova and parasite (OP) examinations of stool specimens from 8109 patients visited at Hospital de la Santa Creu i Sant Pau, Barcelona, Spain, between 2004 and 2006 to evaluate the utility of such tests in multiple, independently-collected stool specimens.

Methods: Multiple-specimens from a single patient were considered related to the same clinical episode if collected within 14 days. A series was thus defined as specimens of the same clinical evaluation. A positive result was defined as the presence of pathogenic OP in stool specimen. Presence of Trichomonas hominis, Chilomastix mesnili, Endolimax nana and Entamoeba coli were also considered positive. A second or third specimen was considered positive for a parasite only if the previous specimens were negative. As a positive result for another parasite in the same series was considered a further positive result, a single series could have more than one positive result. Standard parasitological techniques were used.

Results: Of the 12,862 specimens submitted, 10,086 corresponded to single-specimen series, 1942 to 2-specimen series and 734 to 3 or more specimen series. To evaluate the utility of multiple-specimen examination we focused on series of at least 3 specimens. The first specimen collected was diagnostic in 49.15% (29 of 59) evaluated cases. The examination of 2 specimens increased sensitivity to 79.66% (47 of 59). The third specimen collected provided additional information in 12 cases (20.34%). Information provided by the first specimen, in comparison with the second, was not statistically significant (p = 0.074), although a tendency was observed. Differences between information provided by the first and third specimen were statistically significant (0.006). Differences between second and third specimens were not statistically significant (p = 0.352).

Conclusions: These data suggest that 2 specimens per series should be studied in order to achieve sensitivity closest to 80%. As the difference in information provided by the second and third specimens is not significant, a third specimen is not needed.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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