[Current status of external quality assessment of syphilis test in Korea].
BACKGROUND
Current status of external quality assessment (EQA) of laboratory tests for syphilis in Korea was analyzed to find out the problems that should be improved in the future.


METHODS
Based on the data from the external quality assessment program performed twice a year by the Immunoserology Subcommittee of the Korean Association of Quality Assurance for Clinical Laboratory from the year 2004 to 2006, discordance rates were analyzed according to the test method and commercial kit used.


RESULTS
Among the laboratories participating in the EQA program for syphilis test, about 90% of them used non-treponemal tests and about 55% treponemal tests. The non-treponemal tests included RPR (rapid plasma reagin) and VDRL tests used in 88% (363/412) and 11% (45/412), respectively, of the laboratories. The discordance rates were 2.2% for RPR test and 3.6% for VDRL. For the treponemal tests, Treponema pallidum hemagglutination assay (TPHA) was used in 60-76% and Immunochromatography assay (ICA) in about 30% of the laboratories in 2006. A high discordance rate of over 10% was reported in both TPHA and in ICA methods, possibly due to a low titer (1:1 in VDRL) of EQA samples in 2005. Analysis of the accumulated data from year 2004 to 2006 showed that the discordance rates of TPHA, ICA, and FTA-ABS were 4.6%, 3.7%, and 2.7%, respectively.


CONCLUSIONS
For syphilis tests, RPR test, TPHA, and ICA are mainly used in Korea. A high discordance rate is still reported in TPHA and ICA, especially when testing samples with a low titer. Further analysis of data and education of laboratory personnel are needed for the improvement of the EQA program.
Song
Eun Young
EY
Department of Laboratory Medicine, Konkuk University College of Medicine, Seoul, Korea.
Yang
Joo-Seok
JS
Chae
Seok-Lae
SL
Kim
Serim
S
Choi
Young Sook
YS
Cha
Young-Joo
YJ
D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D016508:Fluorescent Treponemal Antibody-Absorption Test; D006801:Humans; D007723:Korea; D011786:Quality Control; D011933:Reagent Kits, Diagnostic; D013587:Syphilis / Q000175:diagnosis*; D013588:Syphilis Serodiagnosis / Q000379:methods / Q000592:standards*; D014209:Treponema Immobilization Test
D011933:Reagent Kits, Diagnostic