Enhanced therapy for primary and secondary syphilis: a longitudinal retrospective analysis of cure rates and associated factors

Abstract

For the treatment of early infectious syphilis, enhanced therapy with three dosages of benzathine penicillin G has been under consideration, particularly in the human immunodeficiency virus type 1 infected population (HIV-1). The serological outcome of 249 patients with primary and secondary syphilis treated with standard or enhanced therapy was analyzed retrospectively; 98% (139/142) achieved serological cure with a single dosage and 92% with enhanced therapy (P=0.033). In HIV-1 infected individuals, cure rates were 88% after a single dosage compared to 97% after three dosages (P=0.18). A fourfold decrease of Venereal Disease Research Laboratory (VDRL) titres was achieved within a median of 102 days after treatment initiation (SD=2; 95% CI=98-106). Patients aged over 40 years were 5.5 times (OR=5.52; 95% CI=1.43-21.32; P=0.013) and patients with low baseline VDRL titres (≤ 1:32) were 4 times (OR=4.25; 95% CI=1.21-14.87; P=0.024) more likely to experience serological failure.