OBJECTIVE: To determine the rate of the prozone phenomenon in our patient population. METHODS: Sera from 4328 patients--3504 females (2065 pregnant, 1439 nonpregnant) and 824 males--were tested for syphilis by the rapid plasma reagin (RPR) test, and then rechecked with serial twofold dilutions of up to 16-fold to detect the prozone phenomenon. Chi-square analysis with Yates correction was used, with P < or = .05 considered significant. RESULTS: The total positivity rate in females was 6% (213 patients); 13% (27) of the positive tests were false-positive reactions as confirmed by a negative anti-treponemal antibody test. Only one prozone reaction was detected, in serum from a male subject, but it was not missed on initial screening. CONCLUSION: The rate of prozone phenomenon is very low (95% confidence interval 0-0.4%), and routine serial dilutions are not cost effective.
OBJECTIVE: To determine the rate of the prozone phenomenon in our patient population. METHODS: Sera from 4328 patients--3504 females (2065 pregnant, 1439 nonpregnant) and 824 males--were tested for syphilis by the rapid plasma reagin (RPR) test, and then rechecked with serial twofold dilutions of up to 16-fold to detect the prozone phenomenon. Chi-square analysis with Yates correction was used, with P < or = .05 considered significant. RESULTS: The total positivity rate in females was 6% (213 patients); 13% (27) of the positive tests were false-positive reactions as confirmed by a negative anti-treponemal antibody test. Only one prozone reaction was detected, in serum from a male subject, but it was not missed on initial screening. CONCLUSION: The rate of prozone phenomenon is very low (95% confidence interval 0-0.4%), and routine serial dilutions are not cost effective.
Authors: Lara E Pereira; Joshua McCormick; Tandin Dorji; Joseph Kang; Yongcheng Sun; Mayur Shukla; Andre Hopkins; John Deutsch; Ellen N Kersh; Kyle Bernstein; Yetunde F Fakile Journal: J Clin Microbiol Date: 2018-09-25 Impact factor: 5.948
Authors: Jennifer Luchavez; Joanne Baker; Sheila Alcantara; Vicente Belizario; Qin Cheng; James S McCarthy; David Bell Journal: Malar J Date: 2011-09-29 Impact factor: 2.979