Observations on syphilis in Addis Ababa. 2. Prevalence and natural history.

Sera from various groups were tested for syphilis by cardiolipin, fluorescent treponemal antibody-absorbed (FTA-ABS), and treponemal haemagglutination (TPHA) tests. The proportion of positive results, 12.7%, obtained from an unselected urban population suggested that the prevalence of the disease had declined since 1953. The probable explanation is the widespread use of penicillin. Late manifestations of syphilis are much rarer in Ethiopia than would be predicted from the high incidence at the infectious stage and, if present, they affect the cardiovascular system. These findings confirm old observations. Llymphocytes from Ethiopians with early syphilis did not proliferate when cultured with Treponema pallidum in vitro, in contrast with cells from patients with cardiovascular syphilis. These findings differed from observations made previously on patients in England with early syphilis.