Persistence of treponemes after treatment

Current standards for syphilis treatment: comparing the russian and foreign guidelines (part II)

The introduction of penicillin has been a breakthrough in the treatment of syphilis. For 70 years, penicillin remains the preferred drug for the treatment of all forms of the disease; its effectiveness has been proven by wide experience gained from clinical observations. However, a very limited number of published meta-analyzes, systematic reviews and data from randomized controlled trials on the comparative assessment of the effectiveness of various antibiotics and treatment regimens are currently available. Some aspects of syphilis treatment are insufficiently developed, particularly, the treatment schedules for neurosyphilis, syphilis in pregnancy, syphilis in HIV-infected individuals and persons allergic to penicillin. There are disagreements in the assessment of the clinical significance of serofast state after a course of antibiotic therapy. There is no uniform approach to the management of patients with treatment failures. This article compares the Russian standards for syphilis treatment set out in the «Federal guidelines for the management of patients with syphilis» with the current European recommendations of the International Union against Sexually Transmitted Infections (IUSTI) and the recommendations of the US Centers for Disease Control and Prevention (CDC). The peculiarities of these guidelines, their strengths and shortcomings, as well as controversial issues of syphilis therapy are discussed. The differences between the domestic and foreign recommendations are more significant in the section concerning the treatment of syphilis than in the section of diagnosis.

Modern neurosyphilis--a critical analysis

Neurosyphilis remains a source of perplexity for today's physicians. Controversies exist over the interpretation of serologic tests, cerebrospinal fluid (CSF) abnormalities, diagnostic criteria, and treatment regimens. Its occurrence with human immunodeficiency virus (HIV) infection has raised fears of its recrudescence. A critical analysis of the evidence behind these viewpoints leads to several conclusions: the CSF VDRL is the most appropriate diagnostic test; pleocytosis is the only reliable CSF measure of disease activity; commonly accepted diagnostic criteria do not exclude nonsyphilitic disease; and treatment requires the prolonged use of parenteral penicillin, but no superior regimen has been found. Most data do not currently support the view that concurrent HIV infection produces accelerated or resistant neurosyphilis.

Survival of treponemes after treatment: comments, clinical conclusions, and recommendations

Treponemes may persist after treatment that has been accepted as effective; the reasons for this are discussed. Nevertheless, the epidemic of syphilis after the second world war was not followed by an epidemic of late syphilis, and the results of treatment with penicillin are excellent. Neurological signs may progress in some treated patients, and the standard doses of soluble penicillin and any dose of benzathine penicillin (even with added probenecid by mouth) cannot be relied on to achieve treponemicidal concentrations in the cerebrospinal fluid (CSF). There are no large scale studies of CSF findings after treatment of early syphilis with benzathine penicillin. Standard dosage, such as procaine penicillin G 600 000 international units (IU) by intramuscular injection for 10 days, is the treatment of choice for the patient suffering from uncomplicated early syphilis; this should be preferred to benzathine penicillin, which should only be used when standard treatment as above cannot be given. Treponemicidal concentrations of penicillin should be achieved in the CSF of patients suffering from neurosyphilis by schedules of probenecid by mouth and procaine penicillin by single daily intramuscular injections; treatment should last for 17 to 21 days. Benzathine penicillin should not be used for the treatment of patients suffering from neurosyphilis or from the iritis of late syphilis including that accompanying interstitial keratitis. Treatment for interstitial keratitis should initially be as for neurosyphilis, but in recurrent cases it may have to be prolonged to eradicate Treponema pallidum that is dividing slowly. Doxycycline 200 mg by mouth daily for 21 days provides a supervisable outpatient schedule for patients allergic to penicillin. Cephaloridine (and probably cefuroxime and the new cephalosporins) may be useful for patients who are allergic to penicillin but have not developed anaphylactic allergy. If erythromycin is used for treating syphilis in pregnant women who are allergic to penicillin, then the newborn babies should be treated with penicillin.

Penicillin concentrations in blood and spinal fluid after a single intramuscular injection of penicillin G benzathine

The concentration of penicillin in cerebrospinal fluid and blood was measured after a single i.m. injection of 1.44 g penicillin G benzathine in 18 individuals (4 with neurosyphilis and 14 with neurological symptoms but not syphilis). Only one person had a treponemicidal concentration in the cerebrospinal fluid.

Modern neurosyphilis: a partially treated chronic meningitis

Approximately 5,000 new cases of neurosyphilis may occur in the United States each year. General paresis and tabes dorsalis, however, have become relatively rare since the introduction of penicillin. Seizures, neuro-ophthalmologic symptoms, stroke and acute meningoencephalitis are currently the most common manifestations of neurosyphilis. In more than a third of patients with neurosyphilis, nontreponemal tests for syphilis (such as VDRL) are negative and should not be used to exclude the diagnosis. Specific treponemal tests are more sensitive and more specific. Examination of the cerebrospinal fluid may show no abnormalities in neurosyphilis and is not an infallible guide to the activity of the infection. Penicillin is the only proven antibiotic treatment of neurosyphilis. However, low-dose regimens do not produce spirocheticidal concentrations in the brain, and high-dose penicillin therapy is recommended to insure eradication of the spirochetes. Doxycycline, a tetracycline derivation that achieves relatively high concentration in the brain, may also be effective.

Penicillin concentrations in cerebrospinal fluid after different treatment regimens for syphilis

The concentrations of penicillin in the cerebrospinal fluid (CSF) were compared simultaneously with those in the serum in 17 patients with syphilis. The antibiotic concentrations were measured by the agar well diffusion method. There were no detectable concentrations of penicillin in the CSF after administration of benzathine penicillin 2.4 megaunits, benzathine penicillin 7.2 megaunits, procaine penicillin in aluminium monostearate (PAM) 12 megaunits, or aqueous procaine penicillin G 2.4 megaunits. Only after high doses of aqueous penicillin G 24 megaunits daily or aqueous penicillin G 2 megaunits daily together with oral probenecid 2 g daily was penicillin detectable in the CSF. The concentrations after the latter regimen were the highest and much higher than the minimum inhibitory concentration for Treponema pallidum.