Syphilis and HIV: Old and new foes aligned against us

Efficacy and Safety of Treatments for Different Stages of Syphilis: a Systematic Review and Network Meta-Analysis of Randomized Controlled Trials and Observational Studies

Parenteral penicillin is the first-line regimen for treating syphilis. However, allergic reactions and poor drug tolerance still present challenging problems with respect to use of this antibiotic. This study aimed to evaluate the efficacy and safety of ceftriaxone, erythromycin, minocycline, tetracycline, and doxycycline for syphilis treatment, compared with penicillin, to determine which antibiotic could be a better substitute for penicillin. This study included 17 articles, comprising 3 randomized controlled trials (RCTs) and 14 observational studies and involving 4,485 syphilis patients. Estimated risk ratios (RRs) and 95% confidence interval (CIs) were used to compare the serological response rates. At the 6- and 12-month follow-ups, the serological response rates were compared by direct meta-analysis and network meta-analysis (NMA). Based on direct meta-analysis, the serological response rates at the 3- and 24-month follow-ups were compared. Our NMA showed a higher serological response rate for ceftriaxone than for penicillin at the 6-month follow-up (RR of 1.12, 95% CI of 1.02 to 1.23). Ceftriaxone was equally effective as penicillin for syphilis in terms of serological response rates, and it was a better substitute for penicillin than ceftriaxone, erythromycin, minocycline, tetracycline, or doxycycline. However, more large-scale, high-quality, double-blind trials are still needed to determine whether ceftriaxone can safely replace penicillin for the treatment of syphilis when necessary. IMPORTANCE Parenteral penicillin is the first-line regimen for syphilis treatment. However, allergic reactions and poor drug tolerance still present emerging threatening problems with respect to use of this antibiotic. Our results showed a higher serological response rate for ceftriaxone than for penicillin at the 6-month follow-up. Sufficient data are not available for demonstrating significant differences in the efficacy of the other four antibiotics (erythromycin, minocycline, tetracycline, and doxycycline) for treating syphilis. In the clinical treatment of syphilis in patients who are allergic to penicillin or for whom penicillin is not available, ceftriaxone appears to be a better alternative treatment. This meta-analysis provides a reference for clinical treatment of syphilis. Currently, a lack of sufficient evidence to guide antibiotic treatment of syphilis exists, and a need for more high-quality RCTs is still present. This network meta-analysis can lay a foundation for further research.

The "Scourge of the Renaissance". A Short Review About Treponema pallidum infection

BACKGROUND

There is not a time in the history when epidemics did not loom large: infectious diseases have always had civilisation and evolution-altering consequences. Throughout history, there have been a number of pandemics: cholera, bubonic plague, influenza, smallpox are some of the most brutal killers in human history. Historical accounts of pandemics clearly demonstrate that war, unhygienic conditions, social and health inequality create conditions for the transmission of infectious diseases, and existing health disparities can contribute to unequal morbidity and mortality. The Renaissance was a period of European cultural, artistic, political and economic "rebirth" following the Middle Ages, but it was also the time when new infectious disease appeared, such as Syphilis. The epidemic spread of Syphilis began between the late 15th century and early 16th century due to the increased migration of peoples across Europe. The rapid spread of venereal syphilis throughout Europe suggests the introduction of a disease into a population that had not previously been exposed. Syphilis is a type of treponematosis, which includes syphilis, bejel, yaws, and pinta, but, while syphilis is venereal disease, the others are nonvenereal. Syphilis was, at the beginning, a disease of great severity due to its novelty, as the population had no time to gain any immunity against this venereal disease.

METHODS

The purpose of this study is to investigate the origin of syphilis and the evolution of the treatments from the empiric means to the discovery of penicillin, but also to understand how this venereal disease has largely influenced human lifestyle and evolution.

CONCLUSION

The first of the three hypotheses about its origins is the Columbian hypothesis, which states that Columbus's crew acquired syphilis from Native Americans and carried it back to Europe in 1493 A. D. On the contrary, the second hypothesis (pre-Columbian) asserts that syphilis was present in Europe long before Columbus's voyage and was transferred to the New World by Columbus's men. The Unitarian theory argues that syphilis, bejel, yaws, and pinta are not separate diseases but they represent syndromes caused by slightly different strains of one organism. Nowadays, Syphilis' origin is still uncertain and remains controversial. However, the large impact on the social behavior and international public health is an important reason to investigate about its origins and how to prevent the transmission.

Azithromycin vs penicillin G benzathine for early syphilis: A meta-analysis of randomized controlled trials

Syphilis is a very serious infection that causes acute cutaneous manifestations. Penicillin is the gold standard for treating syphilis. This meta-analysis was conducted based on self-published randomized controlled trials (RCTs) data to compare the efficacy of azithromycin with penicillin for treating syphilis. RCTs on azithromycin vs penicillin for the treatment of syphilis were retrieved from the Cochrane Library, MEDLINE, EBSCO, Embase, Ovid, and other databases, and the estimated risk ratio (RR) and 95% confidence interval (CI) were used to study the following outcome indicators: 3-month response rate, 6-month response rate, 12-month response rate, recurrence rate, serum fixation rate, and failure rate. This meta-analysis included seven RCTs involving 639 subjects (of whom 335 were treated with azithromycin and 304 were treated with penicillin). There was no significant difference in the 3-month response rate (RR = 0.97, 95% CI: 0.79-1.19), 6-month response rate (RR = 1.01, 95% CI: 0.85-1.20), 12-month response rate (RR = 1.02, 95% CI: 0.97-1.09), serum fixation rate (RR = 0.71, 95% CI: 0.24-2.12), and failure rate (RR = 0.62, 95% CI: 0.33-1.16). In summary, there is no evidence in the literature that azithromycin is less effective than penicillin for treating syphilis.

Comparison of efficacy of treatments for early syphilis: A systematic review and network meta-analysis of randomized controlled trials and observational studies

BACKGROUND

Parenteral penicillin is the first-line regimen for treating syphilis, but unsuitable for some patients due to penicillin allergy and lacking health resources. Unfortunately, the efficacy of penicillin alternatives remains poorly understood. This study aimed to assess the efficacy of ceftriaxone and doxycycline/tetracycline in treating early syphilis relative to that of penicillin, and thereby to determine which antibiotic is a better replacement for penicillin.

METHOD

By searching literature from PubMed, Cochrane Central Register of Controlled Trials, Embase, the Web of Science, and ClinicalTrials.gov and systematically screening relevant studies, eligible randomized controlled trials (RCTs) and observational studies on treatments with penicillin, doxycycline/tetracycline, and ceftriaxone for early syphilis were identified and combined in this systematic review. Estimated risk ratios (RRs) and 95% confidence intervals (CIs) were utilized to compare their serological response and treatment failure rates. At 12-month follow up, serological response rates were compared by a direct meta-analysis and network meta-analysis (NMA), while treatment failure rates were compared with a direct meta-analysis.

RESULT

Three RCTs and seven cohort studies were included in this research. The results of NMA demonstrated that no significant differences existed in serological response rate at 12-month follow-up between any two of the three treatments (doxycycline/tetracycline vs. penicillin RR = 1.01, 95%CI 0.89-1.14; ceftriaxone vs. penicillin RR = 1.00, 95%CI 0.89-1.13; ceftriaxone vs. doxycycline/tetracycline RR = 0.99, 95%CI 0.96-1.03), which was consistent with the outcomes of the direct meta-analysis. In addition, the direct meta-analysis indicated that, at 12-month follow-up, penicillin and ceftriaxone treatment groups had similar treatment failure rates (RR = 0.92, 95%CI 0.12-6.93), while treatment failure rate was significantly lower among penicillin recipients than among doxycycline/tetracycline recipients (RR = 0.58, 95%CI 0.38-0.89).

CONCLUSION

Ceftriaxone is as effective as penicillin in treating early syphilis with regard to serological response and treatment failure rate. Compared with doxycycline/tetracycline, ceftriaxone appears to be a better choice as the substitution of penicillin.

Neurosyphilis in HIV-infected patients

A review article is addressed the issue of the diagnosis and treatment of neurosyphilis that is developing against the background of HIV-infection. HIV-infected patients are at higher risk of neurologic, ocular and auricular manifestation of syphilis as well as treatment failures and relapses. Diagnosis of neurosyphilis in HIV-positive patients is complicated because both infections cause similar changes in the cerebrospinal fluid (CSF). The effectiveness of neurosyphilis treatment in patients with HIV co-infection is difficult to estimate, since the normalization of their CSF goes slower comparing to HIV-negatives. The increase in incidence of syphilis and HIV co-infection is anticipated in the coming years. This necessitates a comprehensive study of the problem and requires the development of new approaches to neurosyphilis diagnosis and treatment in co-infected patients.

The immunopathobiology of syphilis: the manifestations and course of syphilis are determined by the level of delayed-type hypersensitivity

Syphilis has plagued mankind for centuries and is currently resurgent in the Western hemisphere. Although there has been a significant reduction of tertiary disease and recognition of facilitative interactions with human immunodeficiency virus infection, the natural history of syphilis has remained largely unchanged; thus, new strategies are required to more effectively combat this pathogen. The immunopathologic features of experimental syphilis in the rabbit; the course, stages, and pathology of human syphilis; and a comparison of human syphilis with leprosy suggest that the clinical course of syphilis and its tissue manifestations are determined by the balance between delayed-type hypersensitivity (DTH) and humoral immunity to the causative agent, Treponema pallidum. A strong DTH response is associated with clearance of the infecting organisms in a well-developed chancre, whereas a cytotoxic T-cell response or strong humoral antibody response is associated with prolonged infection and progression to tertiary disease. Many of the protean symptoms/appearances of secondary and tertiary human syphilis are manifestations of immune reactions that fail to clear the organism, due to a lack of recruitment and, more importantly, activation of macrophages by sensitized CD4 T cells. The Bacillus Calmette-Guerin vaccination can enhance DTH and has been shown to produce a low, but measurable, beneficial effect in the prevention of leprosy, a disease that shows a disease spectrum with characteristics in common with syphilis. In the prevention of syphilis, a potential vaccine protective against syphilis should be designed to augment the DTH response.

Review for disease of the year: differential diagnosis of ocular toxoplasmosis

The diagnosis of ocular toxoplasmosis is mainly clinical, based in the presence of focal necrotizing retinochoroiditis often associated with a preexistent chorioretinal scar, and variable involvement of the vitreous, retinal blood vessels, optic nerve, and anterior segment of the eye. Recognition of this clinical spectrum of toxoplasmic retinochoroiditis is crucial, but other infectious, noninfectious, and neoplastic entities should also be considered in the differential diagnosis. Investigations such as serological tests, polymerase chain reaction of ocular fluids, and assessment of intraocular antibody synthesis are helpful in uncertain cases. This article provides an overview of the differential diagnosis of ocular toxoplasmosis, focusing on the most important entities to be considered and emphasizing distinctive features of each one of them in the clinical setting. Ocular toxoplasmosis has multiple clinical manifestations, which partially overlap with those of other entities and these should be carefully considered when making the differential diagnosis, particularly in less typical cases.

Challenging cases discussed by experts: retinal vasculitis following coinfection with HIV and syphilis

A patient with HIV and syphilis presents with bilateral retinal vasculitis and recurrent vitreous hemorrhage. Diagnostic and treatment strategies are discussed.