In 1985, approximately 28 000 cases of primary and secondary syphilis were reported in the United States (Centers for Disease Control, unpublished data). A large proportion of these patients were treated with the recommended therapy, 2.4 million units of penicillin G benzathine given intramuscularly in one dose.1 The proportion of patients who were cured with this regimen, however, is not known. No simple test is available that determines cure of syphilis within days (or even weeks) of treatment. To assess treatment, the patient is asked to return for a repeated serological test and clinical evaluation at varying intervals after treatment, usually 3-, 6-, and 12-month visits or until the patient is seronegative. When the serological test results revert to negative, the patient is considered cured. However, when they remain positive, a clinical dilemma arises.
Criteria for determining treatment failures (or possible failures) during follow-up visits include the following: (1)