SINCE 1984, in many areas of the United States, reported rates of syphilis have greatly increased.1 Between 1984 and 1987, annual rates of syphilis (primary and secondary) increased 70% in the state of Connecticut and 74% in the city of Philadelphia (Figure 1). These trends have continued in 1988; in the first quarter of this year, annualized rates increased by 70% in Connecticut and by 25% in Philadelphia compared with 1987 annual rates. Investigations were conducted at these two sites to identify factors associated with this increase.
In Philadelphia and Connecticut, over 80% of all newly diagnosed patients with early syphilis are interviewed and counseled. Cases are detected through reporting by public clinics and private health-care providers and through laboratory screening. During the interviews, information is collected about patients' lifestyles to help locate sexual contacts. In Philadelphia and Connecticut, records from these interviews were abstracted and analyzed for the