TABLE 1.
Comparison of results prior to and after testing of specimens with discrepant resultsa
| Organism | Result (no. of specimens) | No. of specimens with the indicated result
|
|||||
|---|---|---|---|---|---|---|---|
| Trichrome, modified acid-fast staining and/or Merifluor DFA (reference methods)
|
ImmunoCard STAT! Cryptosporidium/Giardia combination rapid solid-phase qualitative immunochromato- graphic assay
|
After FA to resolve discrepancies
|
|||||
| Pos | Neg | Pos | Neg | Pos | Neg | ||
| G. lamblia | Pos (170) | 170 | 0 | 159 | 11b | 170 | 0 |
| Neg (231) | 0 | 231 | 0 | 231 | 0 | 231 | |
| Total (401) | |||||||
| C. parvum | Pos (85) | 85 | 0 | 84 | 1c | 85 | 0 |
| Neg (316) | 0 | 316 | 0 | 316 | 0 | 316 | |
| Total (401) | |||||||
a
Abbreviations: DFA, direct fluorescent-antibody assay; FA, fluorescent-antibody assay; Pos, positive; Neg, negative.
b
Specimens with false-negative results for G. lamblia had low parasite numbers (n = 7) or trophozoites only (n = 3); one specimen with a false-negative result contained numerous cysts.
c
The one specimen with a false-negative result for C. parvum was confirmed to be positive by immunofluorescence.