From the Guidelines
The positive test for Treponema pallidum indicates syphilis infection, and the recommended treatment is benzathine penicillin G, administered as a single intramuscular injection of 2.4 million units for primary, secondary, or early latent syphilis (less than one year duration) 1.
Treatment Options
- For late latent syphilis or syphilis of unknown duration, the recommended regimen is benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks.
- For patients with penicillin allergy, doxycycline 100 mg orally twice daily for 14 days (primary, secondary, early latent) or 28 days (late latent) can be used as an alternative.
Management of Sex Partners
- Sexual partners from the past 90 days should be notified, evaluated, and treated presumptively 1.
- Long-term sex partners of patients who have latent syphilis should be evaluated clinically and serologically for syphilis and treated on the basis of the evaluation findings.
Follow-up and Prevention
- Follow-up serologic testing is essential at 6 and 12 months after treatment to confirm adequate response 1.
- Patients should abstain from sexual contact until treatment is completed and lesions are healed.
- Treponema pallidum is a spirochete bacterium that causes syphilis and cannot be cultured in the laboratory, making serologic testing crucial for diagnosis 1.
- Penicillin remains highly effective because T. pallidum has not developed resistance to this antibiotic.
Important Considerations
- The Jarisch-Herxheimer reaction is an acute febrile reaction that may occur within the first 24 hours after any therapy for syphilis, and patients should be informed about this possible adverse reaction 1.
- Antipyretics may be used to manage symptoms, but they have not been proven to prevent this reaction.
From the Research
T. pallidum Positive Diagnosis and Treatment
- T. pallidum is the causative agent of syphilis, a chronic, multi-stage infectious disease that can be transmitted sexually or congenitally 2, 3.
- The disease has several stages, including primary, secondary, and latent syphilis, with various symptoms and complications 3.
- There is no vaccine to prevent syphilis, and control is mainly dependent on the identification and treatment of infected individuals and their contacts 2.
Antibiotic Treatment Options
- Penicillin G is the first-line drug for all stages of syphilis, and benzylpenicillin derivatives can cure the disease in most cases at any stage 2, 3.
- Azithromycin is a second-line drug that has been shown to be effective in treating syphilis, particularly in developing countries where penicillin G benzathine injections are problematic 4, 5.
- However, the emergence of azithromycin-resistant T. pallidum has resulted in treatment failures, and the routine use of this drug is no longer recommended 2, 6.
Treatment Efficacy and Safety
- Studies have compared the efficacy and safety of azithromycin versus penicillin G benzathine for the treatment of early syphilis, with mixed results 4, 5, 6.
- A Cochrane review found no statistically significant difference between azithromycin and benzathine penicillin treatment in the odds of cure, but noted that the reporting of adverse events was limited 5.
- Another study found that single-dose azithromycin achieved a similar serological response to benzathine penicillin G in HIV-infected patients with early syphilis, but with more gastrointestinal symptoms and lassitude/somnolence 6.