TABLE 1.
Algorithm for determining results of tests for C. trachomatisa
| PCE EIA resultb | Cobas PCR result | Commentc | Final report |
|---|---|---|---|
| + | + | True positive | |
| NGZ | + | True positive | |
| − | + | If confirmatory NAAT on 2nd aliquot is positive | True positive |
| + | − | If confirmatory NAAT on 2nd aliquot is positive | True positive |
| NGZ | − | If confirmatory NAAT on 2nd aliquot is positive | True positive |
| − | + | If confirmatory NAAT on 2nd aliquot is negative | True negative |
| + | −d | If confirmatory NAAT on 2nd aliquot is negative | True negative |
| NGZ | −d | If confirmatory NAAT on 2nd aliquot is negative | True negative |
| − | −d | True negative |
a
Adapted from section 10 of the Chlamydia Screening Studies Laboratory Protocol (www.chlamydia.ac.uk/evaldiag.htm) with permission.
b
NGZ, negative gray zone.
c
Original urine was tested by confirmatory NAAT if the volume allowed it (1 ml was required for real-time PCR). Otherwise, the residual urine was used.
d
Internal control used to detect inhibitory specimens. Inhibitory specimens were retested by using a second NAAT (see Materials and Methods).