LIPOIDAL ANTIGEN AND TPI REACTIONS IN SERA FROM ETHIOPIA. EFFECT OF LONG-DISTANCE SERUM TRANSPORTATION ON ANTIBODIES.

In order to evaluate results obtained in Addis Ababa with lipoidal antigen tests for syphilis on 269 human sera, and, if possible, to determine how many positive seroreactors were in fact infected with Treponema pallidum, these sera were sent by air to Copenhagen for re-examination by the VDRL, Kahn, CWRM and TPI tests.Approximately 60% of sera reactive in VDRL tests in Ethiopia were also VDRL-reactive in Copenhagen, and some 75% were TPI-reactive. As the same VDRL techniques were used in the two laboratories, the difference in reactivity is attributed to antibody loss during transport. Sera non-reactive in TPI testing but VDRL-reactive in Addis Ababa are considered to be non-treponemal, showing false positive reactions.The low rate of agreement between the Addis Ababa VDRL tests and the Copenhagen TPI tests on sera from persons under 21 years suggests that congenital syphilis is rare in Ethiopia, in confirmation of clinical findings. However, the author considers that no conclusions on the prevalence of syphilis in Ethiopia can be drawn from the over-all results of this study.