What is the treatment for an asymptomatic syphilis infection with a reactive Rapid Plasma Reagin (RPR) test and a titer of 1:128, confirmed by Treponema pallidum Antibodies?

From the Guidelines

The recommended treatment for this new syphilis infection without symptoms is a single intramuscular injection of Benzathine Penicillin G 2.4 million units, as this is the standard treatment for early latent syphilis, which is defined as infection acquired within the past 12 months. This treatment approach is based on the most recent guidelines, although the provided evidence does not directly address the specific treatment for asymptomatic syphilis infection with a reactive RPR and high titer of 1:128, as well as reactive treponemal antibodies 1.

Key Considerations

• The patient's laboratory results show a reactive RPR with a high titer of 1:128 and reactive treponemal antibodies, confirming syphilis infection despite the absence of symptoms.
• Penicillin is particularly effective because it crosses the blood-brain barrier and can prevent progression to neurosyphilis.
• For penicillin-allergic patients, doxycycline 100 mg orally twice daily for 14 days (early latent) or 28 days (late latent) is an alternative.
• Sexual partners from the past 90 days should be evaluated and treated presumptively.
• Follow-up serologic testing should be performed at 6 and 12 months after treatment to confirm adequate response, indicated by a four-fold decrease in RPR titer.

Treatment Approach

• If the duration of infection cannot be determined or is likely longer than 12 months, the treatment should be extended to three weekly injections of Benzathine Penicillin G 2.4 million units (for a total of 7.2 million units) 1.
• The patient should be evaluated for neurosyphilis and re-treated appropriately if a) titers increase fourfold, b) an initially high titer (greater than or equal to 1:32) fails to decline at least fourfold (i.e., two dilutions) within 12-24 months, or c) signs or symptoms attributable to syphilis develop in the patient 1.

From the Research

Treatment for Syphilis Infection

The treatment for syphilis infection without symptoms, as indicated by the provided test results (RPR Reactive, Non-Reactive, and Treponema pallidum Antibodies Reactive), can be guided by the following evidence:

• A single dose of 2.4 million units of benzathine penicillin G is the recommended treatment for early syphilis, as stated in 2 and 3.
• Azithromycin has been studied as an alternative treatment, with a single 2-g oral dose showing promise in treating syphilis, as reported in 4 and 5.
• However, the use of azithromycin is limited due to concerns about resistance, as mentioned in 2 and 5.

Treatment Response and Follow-up

• The treatment response should be monitored through serologic tests, with a decline in RPR titers expected after treatment, as discussed in 2 and 3.
• The "serofast state," where patients remain seropositive after treatment, is a recognized phenomenon, and its implications for treatment and follow-up are still being studied, as noted in 3.

Specific Considerations

• For patients with HIV infection, the treatment approach may need to be adjusted, and the use of penicillin as first-line therapy is supported by available data, as stated in 2 and 3.
• Pregnant women should also be treated with penicillin, according to the available evidence, as mentioned in 3.