Abstract:
The purpose of this research is to evaluate the sensitivity and specificity of
three different Enzyme Link Immunosorbent Assay (ELISA) test kits compared with
Rapid Plasma Reagin (RPR) assay which currently is used for syphilis screening in
blood donors and to compare sensitivity and specificity between different ELISA test
kits. One thousand two hundred and fifty unselected donor samples and 206
Treponema pallidum Heamagglutination (TPHA) positive donor samples from Thai
National Red Cross were included in this research. TPHA was used as gold standard.
The sensitivity of ELISA test kits: Bioelisa, Ice Syphilis and New Market were
92.72%, 98.06%, 98.06% respectively while the sensitivity of RPR was 75.24%. The
specificity of Bioelisa, Ice Syphilis, New Market and RPR were 99.18%, 99.51 %,
99.92 %, 99.75 % respectively. A discordant result between TPHA and ELISA test
kits was observed. RPR assay missed 13 TPHA positive cases and Bioelisa missed 15
TPHA positive cases. All cases were detected by New Market and Ice Syphilis ELISA.
Data from this research showed that ELISA had comparable specificity and
higher sensitivity than RPR. Different ELISA tests kit for Syphilis screening have
different sensitivity and specificity. New Market and Ice Syphilis are more suitable
because they have slightly higher sensitivity, higher specificity and significantly
greater accuracy than Bioelisa.