Syphilis

The history, causative agent, diagnosis and treatment of syphilis are described. The causative agent, the spirochete Treponema pallidum, is not routinely grown on laboratory media. The lesion of primary syphilis is usually a painless genital ulcer but chances may appear at other sites. Most patients develop primary disease within 6 weeks of exposure, but the VDRL test is positive in only about 70% of patients with primary syphilis. Secondary syphilis occurs 6 weeks-6 months after the primary inoculation, may have a variety of manifestations, and is diagnosed by serologic studies that are always positive at that stage. Late syphilis develops in about 25% of patients not receiving adequate treatment. Reported cases of primary and secondary syphilis, 27,204 in 1980, and rate of infection/100,000 population, 12.0 in 1980, have been increasing although tertiary syphilis is infrequent. The pathophysiology of the disease is complex because of the interaction of the pathogen and host defense. Syphilis associated with pregnancy presents a special problem because of the risk of fetal infection, but congenital syphilis is preventable and the means for its control are available through public health clinics. Early congenital syphilis, which shows itself within the 1st 2 years, is an infectious life-threatening disease, while late congenital syphilis is usually asymptomatic and may not become manifest for decades. Dark-field microscopic examination is the only absolute diagnosis test for T. pallidum. The VDRL serologic test developed by the Venereal Disease Research Laboratory is widely used as a screening measure, but its accuracy is not absolute. Other tests to confirm diagnoses are available or under development. Penicillin is the antibiotic of choice, although alternative drugs are available for patients with allergies or other contraindications. Dosage schedules vary for different stages of the disease and for congenital syphilis. In all cases of early infectious syphilis the physician should endeavor to see that the source of the infection and those to whom it has been passed are also treated.