(A) comparative study of FTA-ABS test and other STS
[영문]At the present time, syphilis patients who have typical findings of each stage are very rare due to indiscriminate use of antibiotics. Futhermore, the number of syphilis patients is apt to increase progressively because of indiscriminate use of antibiotics.
In Korea, several kinds of serologic tests of syphilis have been used. For example, Venereal Disease Research Laboratory slide flocculation test (VERL test), Kolmer complement fixation test (Kolmer CF test) as non-treponemal antigen tests, and Reiter protein complement fixation test (RPCF test) as treponemal antigen test, have been used.
Nontreponemal antigen tests (reagin test) showed high incidence of biological false positives. Therefore, RPCD test was introduced in 1963 to Korea as trepomenal antigen test with high specificity, but the sensitivity of RPCF test seems to be low.
For further sensitivity studies, fluorescent treponemal antibody (FTA) procedures as an indirect fluorescent microscopic method were developed.
The major cause of nonspecificity in the FTA tests might be occurrence of common or group antigens shared by pathogenic and saprophytic treponemes. And the corresponding nonspecific antibodies could be removed from test serums by the procedure of intact Reiter treponeme or sonic-disrupted Reiter treponema
absorption. At present, a stable water-soluble extract from Reiter treponemed is employed instead of sonicate for fluorescent treponema antibody absorption test (FTA-ABS test).
FTA-ABS test is a specific test, much more sensitive, and cheaper, and more simple than Treponema pallidum immobilization test (TPI test).
And so, the purpose of this report is to visualize the recent trends in the incidence of syphilitic infection in Korea and to introduce FTA-ABS test to Korea as a confirming test of syphilis serodiagnosis which was confirmed by various investigators in the world to be the most sensitive and specific method.
A. The recent trends of syphilis indidence in Korea for the past 10 years or more were ;
1. Many American and European literatures have reported a sharp increase of early syphilis patients in Korea shows abrupt increase since 1963 and 1964, especially early latent and symptomatic syphilis patients which are not teenagers but adults.
2. The cause of increase of early syphilis in this country is due to the spread of syphilis by the prostitutes to the general public after the abolition of licensed prostitution and hesitation of using penicillin because of penicillin hypersensitivity.
B. FTA-ABS tests were performed on 1082 specimens of serum and on 67 specimens of spinal fluid which were collected in the Dept. of clinical pathology of Severance Hospital for serum VDRL titration tests, and RPCF tests of the spinal fluid. The results of them were compared to those of FTA-ABS test and the following results were obtained.
1. In the results of STS of late latent syphilis, and late syphilis, compared to the results of FTA-ABS tests as standard using serums, VDRL test was ,most sensitive, followed by the RPCF test and Kolmer CF test.
2. Specificity of RPCF test, Kolmer CF test and VDRL test, was decreased in order named in comparison to the results of FTA-ABS test.
3. Sensitivity of Kolmer CF test and RPCF test compared with the FTA-ABS test using spinal fluid has seemed to be very low.
4. The results show that FTA-ABS test have been continuously reactive after treatment for syphilis for a period of one year.
Further studies for biological false positive cases of FRA-ABS tests are needed.