Syphilis control in populations previously exposed to yaws.

Application of an epidemiologic strategy, involving repeated annual screening, public relations activities and treatment to selected groups, for syphilis control in four communities is described. The predictive value of the VDRL screening test was influenced by the titre of the test and the age and location of individuals on whom it was performed. The predictive value of 1:8 VDRL titres (for active syphilis) varied from zero in individuals over 50 years of age, in one community to 0.96 in individuals 10-29 years old in another. Reduction in transmission of infection was closely related to the degree of screening coverage of the community and adjacent communities with which intercourse occurred.