The method is designed potentially to be automated plus the reading of results is usually carried out by a microtiter plate reader, thus making the interpretation of results objective, unlike that of the RPR test
which is subjective and hence requires having extensive experience.
VDRL of Cases Reactive Non-Reactive 11-20 24 21 3 21-30 53 43 10 31-40 17 16 1 41 and above 6 5 1 Total 100 85 15 Age RPR TPHA Reactive Non- Reactive Reactive Non- Reactive 11-20 21 3 22 2 21-30 42 11 45 8 31-40 16 1 17 -- 41 and above 5 1 5 1 Total 84 16 89 11 TABLE 4: RESULTS OF MICRO-TPHA TEST IN COMPARISON WITH VDRL AND RPR TESTS
The patient was found to be [HTV.sup.+], the treponemal antibody test result was positive, and the RPR test
result was reactive at a dilution of 1:256.
(29) The sensitivity and specificity, positive and negative predictive values, and likelihood ratios (LRs) for a positive (LR+) and negative (LR-) test were calculated to determine the screening performance of the RPR test
. A cross-tabulation was constructed along with the odds ratio (OR) for syphilis prevalence.
of (% of Population type/Laboratory specimens total) Overall 4,834 (3.4) Low-prevalence population * 2,984 (2.3) Southern California ([dagger]) 1,278 (2.7) Northern California ([paragraph]) 438 (2.0) Southern California ** 1,268 (2.2) High-prevalence population ([dagger][dagger]) 1,850 (14.5) New York City ([section] [section]) 1,165 (15.3) Chicago *** 685 (13.3) Nonreactive reflex nontreponemal RPR test
(% of reactive No.
* Of all 6,548 specimens reactive to the treponemal EIA test and then tested using an RPR test
, 44% were reactive and 56% (3% of the overall sample) non-reactive with an RPR test
This might not tell the entire story, however, since none of the females refused to be tested, while 18 percent of the male detainees refused to take an RPR test
, many of whom could have tested reactive.
At a third laboratory, specimens that were reactive to both the EIA test and the RPR test
were retested using a different treponemal test (i.e., FTA-ABS or TP-PA).
The RPR test
was positive in 5.2% of the women, and 7.1% had a positive TPHA test.