Congenital syphilis in Harris County, Texas, USA, 1990-92: incidence, causes and risk factors.

From local health department data, we determined the 1990-92 incidence of congenital syphilis (CS) in Harris County, Texas, USA, applying for the first time the Centers for Disease Control and Prevention (CDC) 1990 surveillance case definition to a population-based sample. We also evaluated factors that discriminated between women whose infants were or were not cases. The incidence of CS per 1000 live births was 3.2 in 1990, 4.6 in 1991 and 4.2 in 1992. Because of failure to apply part of the case definition, the local health department reported only 60% (418/694) of the cases that we identified. In the multivariate analysis, the significant factors for CS were lack of prenatal care and late latent syphilis. No factor identified high-risk women to target for special public health interventions. Improved laboratory services and better education of local providers and surveillance workers will solve some problems in the diagnosis and therapy of syphilis during pregnancy. Ambiguity in the CDC's case definition of CS needs correction.