Syphilis: antibiotic treatment and resistance

Syphilis is a chronic, multi-stage infectious disease that is usually transmitted sexually by contact with an active lesion of a partner or congenitally from an infected pregnant woman to her fetus. Although syphilis is still endemic in many developing countries, it has re-emerged in several developed countries. The resurgence of syphilis is a major concern to global public health, particularly since the lesions of early syphilis increase the risk of acquisition and transmission of infection with human immunodeficiency virus (HIV). Because there is no vaccine to prevent syphilis, control is mainly dependent on the identification and treatment of infected individuals and their contacts with penicillin G, the first-line drug for all stages of syphilis. The emergence of clinically significant azithromycin resistance in Treponema pallidum subsp. pallidum, the syphilis agent, has resulted in treatment failures, thus precluding the routine use of this second-line drug. Information is presented here on the diagnosis and recommended antibiotic treatment of syphilis and the challenge of macrolide-resistant T. pallidum.

Jarisch-Herxheimer reaction among HIV-positive patients with early syphilis: azithromycin versus benzathine penicillin G therapy

Introduction

The Jarisch-Herxheimer reaction, a febrile inflammatory reaction that often occurs after the first dose of chemotherapy in spirochetal diseases, may result in deleterious effects to patients with neurosyphilis and to pregnant women. A single 2-g oral dose of azithromycin is an alternative treatment to benzathine penicillin G for early syphilis in areas with low macrolide resistance. With its potential anti-inflammatory activity, the impact of azithromycin on the incidence of the Jarisch-Herxheimer reaction in HIV-positive patients with early syphilis has rarely been investigated.

Methods

In HIV-positive patients with early syphilis, the Jarisch-Herxheimer reaction was prospectively investigated using the same data collection form in 119 patients who received benzathine penicillin G between 2007 and 2009 and 198 who received azithromycin between 2012 and 2013, when shortage of benzathine penicillin G occurred in Taiwan. Between 2012 and 2013, polymerase chain reaction (PCR) assay was performed to detect Treponema pallidum DNA in clinical specimens, and PCR restriction fragment length polymorphism of the 23S ribosomal RNA was performed to detect point mutations (2058G or A2059G) that are associated with macrolide resistance.

Results

The overall incidence of the Jarisch-Herxheimer reaction was significantly lower in patients receiving azithromycin than those receiving benzathine penicillin G (14.1% vs. 56.3%, p<0.001). The risk increased with higher rapid plasma reagin (RPR) titres (adjusted odds ratio [AOR] per 1-log₂ increase, 1.21; confidence interval [CI], 1.04–1.41), but decreased with prior penicillin therapy for syphilis (AOR, 0.37; 95% CI, 0.19–0.71) and azithromycin treatment (AOR, 0.15; 95% CI, 0.08–0.29). During the study period, 310 specimens were obtained from 198 patients with syphilis for PCR assays, from whom T. pallidum was identified in 76 patients, one of whom (1.3%) was found to be infected with T. pallidum harbouring the macrolide resistance mutation (A2058G). In subgroup analyses confined to the 75 patients infected with T. pallidum lacking resistance mutation, a statistically significantly lower risk for the Jarisch-Herxheimer reaction following azithromycin treatment was noted.

Conclusions

Treatment with azithromycin was associated with a lower risk for the Jarisch-Herxheimer reaction than that with benzathine penicillin G in HIV-positive patients with early syphilis. Previous benzathine penicillin G therapy for syphilis decreased the risk, whereas higher RPR titres increased the risk, for the reaction.

Syphilis in the modern era: an update for physicians

Syphilis is a complex, systemic disease caused by the spirochete Treponema pallidum. Syphilis is most commonly transmitted sexually or congenitally and can involve nearly every organ system. Its clinical progression involves several well-characterized stages: an incubation period, a primary stage, a secondary stage, a latent stage, and a late or tertiary stage. Syphilis during pregnancy is a leading cause of perinatal mortality in sub-Saharan Africa and can cause spontaneous abortion, stillbirth, prematurity, low birth weight, or congenital syphilis. Penicillin is highly effective against syphilis and remains the treatment of choice. This article reviews the epidemiology, clinical features, diagnostic approach, treatment, and prevention of syphilis.

Azithromycin-resistant syphilis-causing strains in Sydney, Australia: prevalence and risk factors

Azithromycin has shown high efficacy in randomized trials when used for treating infectious syphilis in Africa. However, its use in clinical practice has been limited by the development of antimicrobial drug resistance. Resistance has not previously been reported from Australasia. The aim of this study was to determine the prevalence of and risk factors for azithromycin-resistant syphilis-causing strains in Sydney, Australia. We evaluated 409 samples that were PCR positive for Treponema pallidum DNA collected between 2004 and 2011 for the presence of the A2058G mutation, which confers resistance to macrolide antibiotics such as azithromycin. Overall, 84% of samples harbored the mutation. The prevalence of the mutation increased during the study period (P trend, 0.003). We also collected clinical and demographic data on 220 patients from whom these samples had been collected to determine factors associated with the A2058G mutation; 97% were from men who have sex with men. Reporting sex in countries other than Australia was associated with less macrolide resistance (adjusted odds ratio, 0.25; 95% confidence interval, 0.09 to 0.66; P = 0.005), with other study factors showing no association (age, HIV status, recent macrolide use, stage of syphilis, or history of prior syphilis). Azithromycin cannot be recommended as an alternative treatment for syphilis in Sydney.

The endemic treponematoses

The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents.

Predictors of serological failure after treatment in HIV-infected patients with early syphilis in the emerging era of universal antiretroviral therapy use

BACKGROUND

The optimal treatment of early syphilis (primary, secondary and early latent) in HIV-infected patients remains controversial. The Center for Diseases Control STD Treatment Guidelines recommended 1 dose of benzathine penicillin G (BPG) regardless of HIV infection. However, many providers modify the treatment for early syphilis.

METHODS

We performed a retrospective chart review of all cases of early syphilis with positive serologic test results in HIV-infected patients from May 2006 to May 2011 in 2 large, urban HIV clinics. Early syphilis includes primary, secondary, and early latent syphilis. Serological failure was defined as a lack of 4-fold decrease in rapid plasma reagent (RPR) titers 9 to 12 months after syphilis treatment. Patients whose RPR titers decreased after treatment and subsequently increased 4-fold at 9 to 12 months were excluded from the analysis of serological response because of possibility as "reinfection". Baseline characteristics were tested as predictive factors of serological failure using a univariate and multivariate logistic regression model, respectively.

RESULTS

Of 560 patients with confirmed cases of early syphilis, 51 (9.0%) experienced serological failure. Multivariate logistic regression modeling demonstrated that the predictive factors associated with serological failure after early syphilis treatment were baseline RPR titer ≤ 1:16 (OR 3.91 [95% CI, 2.04-7.47]), a previous history of syphilis (OR 3.12 [95% CI, 1.55-6.26]), and a CD4 T-cell count below 350 cells/ml (OR 2.41 [95% CI, 1.27-4.56]). Of note, type of syphilis treatment (1 dose versus 3 doses of BPG) did not appear to affect the proportion of serological failure (4% versus 10%, P = 0.29), however the power of this study to detect small differences was limited.

CONCLUSIONS

HIV-infected patients with baseline RPR titer ≤1:16, syphilis history, and/or a CD4 T-cell count <350 cells/ml should be closely monitored for serologic failure after early syphilis treatment. This study did not detect a substantial difference between treatment with > 1 dose of BPG and decreased frequency of serological failure, supporting the current recommendation that one dose of BPG is adequate treatment for early syphilis in HIV-infected patients.

On the pathway to better birth outcomes? A systematic review of azithromycin and curable sexually transmitted infections

The WHO recommends the administration of sulfadoxine-pyrimethamine (SP) to all pregnant women living in areas of moderate (stable) to high malaria transmission during scheduled antenatal visits, beginning in the second trimester and continuing to delivery. Malaria parasites have lost sensitivity to SP in many endemic areas, prompting the investigation of alternatives that include azithromycin-based combination (ABC) therapies. Use of ABC therapies may also confer protection against curable sexually transmitted infections and reproductive tract infections (STIs/RTIs). The magnitude of protection at the population level would depend on the efficacy of the azithromycin-based regimen used and the underlying prevalence of curable STIs/RTIs among pregnant women who receive preventive treatment. This systematic review summarizes the efficacy data of azithromycin against curable STIs/RTIs.

Enhanced therapy for primary and secondary syphilis: a longitudinal retrospective analysis of cure rates and associated factors

For the treatment of early infectious syphilis, enhanced therapy with three dosages of benzathine penicillin G has been under consideration, particularly in the human immunodeficiency virus type 1 infected population (HIV-1). The serological outcome of 249 patients with primary and secondary syphilis treated with standard or enhanced therapy was analyzed retrospectively; 98% (139/142) achieved serological cure with a single dosage and 92% with enhanced therapy (P=0.033). In HIV-1 infected individuals, cure rates were 88% after a single dosage compared to 97% after three dosages (P=0.18). A fourfold decrease of Venereal Disease Research Laboratory (VDRL) titres was achieved within a median of 102 days after treatment initiation (SD=2; 95% CI=98-106). Patients aged over 40 years were 5.5 times (OR=5.52; 95% CI=1.43-21.32; P=0.013) and patients with low baseline VDRL titres (≤ 1:32) were 4 times (OR=4.25; 95% CI=1.21-14.87; P=0.024) more likely to experience serological failure.

Response to therapy following retreatment of serofast early syphilis patients with benzathine penicillin

Persistent nontreponemal titers after treatment are common among patients with early syphilis. We retreated 82 human immunodeficiency virus-negative early syphilis participants who were serofast at 6 months using benzathine penicillin. Only 27% exhibited serological response after retreatment and after an additional 6 months of follow-up.

Rapid plasma reagin titer variation in the 2 weeks after syphilis therapy

BACKGROUND

Serologic tests for syphilis results at the time of diagnosis are the basis for evaluating response to syphilis therapy. After treatment, however, serologic tests for syphilis titers may continue to increase for several weeks. We evaluated rapid plasma reagin (RPR) titer variation during the 14 days after therapy using data from a recent large, prospective randomized controlled trial.

METHODS

Prospectively enrolled participants in North America and Madagascar with primary, secondary, or early latent syphilis were randomly assigned to penicillin, doxycycline (in the case of penicillin allergy), or azithromycin treatment. Blood for RPR analysis was drawn at days 0, 7, and 14 posttreatment. All RPR titers were determined simultaneously at a central laboratory.

RESULTS

Four hundred and seventy patients had data available for at least 2 of 3 RPR measurements. Overall, 20% of patients showed a titer increase of at least 1 dilution in the 14 days after therapy. The greatest proportion of titer increases following therapy was observed in patients with primary syphilis. Comparing outcome of therapy using the initial (day 0) RPR titer versus the maximal RPR titer (during 14 days) resulted in outcome reclassification in 2.98% of participants.

CONCLUSIONS

Despite the fact that about 20% of early syphilis patients had increases in RPR titers immediately after treatment, these changes rarely influenced assessment of therapeutic outcome. Only 3% of patients treated would have been reclassified.

Two mutations associated with macrolide resistance in Treponema pallidum: increasing prevalence and correlation with molecular strain type in Seattle, Washington

BACKGROUND

Although azithromycin promised to be a safe and effective single-dose oral treatment of early syphilis, azithromycin treatment failure has been documented and is associated with mutations in the 23S rDNA of corresponding Treponema pallidum strains. The prevalence of strains harboring these mutations varies throughout the United States and the world. We examined T. pallidum strains circulating in Seattle, Washington, from 2001 to 2010 to determine the prevalence of 2 mutations associated with macrolide resistance and to determine whether these mutations were associated with certain T. pallidum strain types.

METHODS

Subjects were enrolled in a separate ongoing study of cerebrospinal fluid abnormalities in patients with syphilis. T. pallidum DNA purified from blood and T. pallidum strains isolated from blood or cerebrospinal fluid were analyzed for two 23S rDNA mutations and for the molecular targets used in an enhanced molecular stain typing system.

RESULTS

Nine molecular strain types of T. pallidum were identified in Seattle from 2001 to 2010. Both macrolide resistance mutations were identified in Seattle strains, and the prevalence of resistant T. pallidum exceeded 80% in 2005 and increased through 2010. Resistance mutations were associated with discrete molecular strain types of T. pallidum.

CONCLUSIONS

Macrolide-resistant T. pallidum strains are highly prevalent in Seattle, and each mutation is associated with discrete strain types. Macrolides should not be considered for treatment of syphilis in regions where prevalence of the mutations is high. Combining the resistance mutations with molecular strain typing permits a finer analysis of the epidemiology of syphilis in a community.

Genital ulcer disease treatment for reducing sexual acquisition of HIV

BACKGROUND

Genital ulcer disease by virtue of disruption of the mucosal surfaces may enhance HIV acquisition. Genital ulcer disease treatment with resolution of the ulcers may therefore contribute in reducing the sexual acquisition of HIV.

OBJECTIVES

To determine the effects of treatment of genital ulcer disease on sexual acquisition of HIV.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, LILACS, NLM Gateway, Web of Science, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and reference lists of relevant publications for eligible studies published between 1980 and August 2011.

SELECTION CRITERIA

Randomized controlled trials of any treatment intervention aimed at curing genital ulcer disease compared with an alternative treatment, placebo, or no treatment. We included only trials whose unit of randomization was the individual with confirmed genital ulcer.

DATA COLLECTION AND ANALYSIS

We independently selected studies and extracted data in duplicate; resolving discrepancies by discussion, consensus, and arbitration by third review author. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

There were three randomized controlled trials that met our inclusion criteria recruited HIV-negative participants with chancroid (two trials with 143 participants) and primary syphilis (one trial with 30 participants). The syphilis study, carried out in the US between 1995 and 1997, randomized participants to receive a single 2.0 g oral dose of azithromycin (11 participants); two 2.0 g oral doses of azithromycin administered six to eight days apart (eight participants); or benzathine penicillin G administered as either 2.4 million units intramuscular injection once or twice seven days apart (11 participants). No participant in the trial seroconverted during 12 months of follow-up. The chancroid trials, conducted in Kenya by 1990, found no significant differences in HIV seroconversion rates during four to 12 weeks of follow-up between 400 and 200 mg single oral doses of fleroxacin (one trial, 45 participants; RR 3.00; 95% CI 0.29 to 30.69), or between 400 mg fleroxacin and 800 mg sulfamethoxazole plus 160 mg trimethoprim (one trial, 98 participants; RR 0.33; 95% CI 0.04 to 3.09). Adverse events reported were mild to moderate in severity, and included Jarisch-Herxheimer reactions and gastrointestinal symptoms. The differences between the treatment arms in the incidence of adverse events were not significant. The quality of this evidence on the effectiveness of genital ulcer disease treatment in reducing sexual acquisition of HIV, according to GRADE methodology, is of very low quality.

AUTHORS' CONCLUSIONS

At present, there is insufficient evidence to determine whether curative treatment of genital ulcer disease would reduce the risk of HIV acquisition. The very low quality of the evidence implies that the true effect of genital ulcer disease treatment on sexual acquisition of HIV may be substantially different from the effect estimated from currently available data. However, genital ulcer diseases are public health problems in their own right and patients with these conditions should be treated appropriately; whether the treatment reduces the risk of HIV infection or not.

Azithromycin versus penicillin G benzathine for early syphilis

BACKGROUND

Syphilis is a complex systemic disease caused by a spirochete, Treponema pallidum. The World Health Organization estimates that at least 12 million people worldwide are currently infected with syphilis. In this review we compared two current standards of treatment for early syphilis, benzathine benzylpenicillin (penicillin G) and azithromycin.

OBJECTIVES

To evaluate the efficacy and safety of azithromycin versus benzathine penicillin (penicillin G) for early syphilis.

SEARCH METHODS

We searched the following databases using the search terms detailed in Appendix 1: the Cochrane Sexually Transmitted Diseases Group Specialized Register (July 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) published in The Cochrane Library (Issue 7 2011), MEDLINE (1948 to July 2011), EMBASE (1980 to July 2011), PsycINFO (1806 to July 2011) and the Chinese Biological Medicine Literature Database (CBM) (1978 to 2011). The search was not limited by language.

SELECTION CRITERIA

Randomized controlled trials comparing azithromycin with benzathine penicillin G at any dose for the treatment of early syphilis.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria to potential studies, with any disagreements resolved by discussion. The risk of bias of each study was assessed by the same two review authors. We pooled data using an odds ratio (OR).

MAIN RESULTS

Three studies (generating four eligible study comparisons) were included. One study is ongoing. There was no statistically significant difference between azithromycin and benzathine penicillin treatment in the odds of cure (OR 1.04, 95% CI 0.69 to 1.56); nor any difference at three months (OR 0.97, 95% CI 0.62 to 1.50), six months (OR 1.09, 95% CI 0.76 to 1.54) or nine months (OR 1.45, 95% CI 0.46 to 6.42). Subgroup analysis by primary and latent syphilis and by dose of azithromycin (2 g and 4 g) did not explain the variation between the study results. The reporting of computed mild to tolerated adverse events, from two included trials, indicated no statistically significant difference between azithromycin and benzathine penicillin (OR 1.43, 95% CI 0.42 to 4.95), although with a high level of heterogeneity (P = 0.05, I(2) = 74%).

AUTHORS' CONCLUSIONS

Differences in the odds of cure did not reach statistical significance when azithromycin was compared with benzathine penicillin for the treatment of early syphilis. No definitive conclusion can be made regarding the relative safety of benzathine penicillin G and azithromycin for early syphilis. Further studies on the utility of benzathine penicillin G for early syphilis are warranted.

Single-dose azithromycin versus benzathine benzylpenicillin for treatment of yaws in children in Papua New Guinea: an open-label, non-inferiority, randomised trial

BACKGROUND

Yaws--an endemic treponematosis and, as such, a neglected tropical disease--is re-emerging in children in rural, tropical areas. Oral azithromycin is effective for syphilis. We assessed the efficacy of azithromycin compared with intramuscular long-acting penicillin to treat patients with yaws.

METHODS

We did an open-label, non-inferiority, randomised trial at Lihir Medical Centre, Papua New Guinea, between Sept 1, 2010, and Feb 1, 2011. Children aged 6 months to 15 years with a serologically confirmed diagnosis of yaws were randomly allocated, by a computer-generated randomisation sequence, to receive either one 30 mg/kg oral dose of azithromycin or an intramuscular injection of 50,000 units per kg benzathine benzylpenicillin. Investigators were masked to group assignment. The primary endpoint was treatment efficacy, with cure rate defined serologically as a decrease in rapid plasma reagin titre of at least two dilutions by 6 months after treatment, and, in participants with primary ulcers, also by epithelialisation of lesions within 2 weeks. Non-inferiority was shown if the upper limit of the two-sided 95% CI for the difference in rates was lower than 10%. The primary analysis was per protocol. This trial is registered with ClinicalTrials.gov, number NCT01382004.

FINDINGS

We allocated 124 patients to the azithromycin group and 126 to the benzathine benzylpenicillin group. In the per-protocol analysis, after 6 months of follow-up, 106 (96%) of 110 patients in the azithromycin group were cured, compared with 105 (93%) of 113 in the benzathine benzylpenicillin group (treatment difference -3·4%; 95% CI -9·3 to 2·4), thus meeting prespecified criteria for non-inferiority. The number of drug-related adverse events (all mild or moderate) was similar in both treatment groups (ten [8%] in the azithromycin group vs eight [7%] in the benzathine benzylpenicillin group).

INTERPRETATION

A single oral dose of azithromycin is non-inferior to benzathine benzylpenicillin and avoids the need for injection equipment and medically trained personnel. A change to the simpler azithromycin treatment regimen could enable yaws elimination through mass drug administration programmes.

FUNDING

International SOS and Newcrest Mining.

Syphilis: using modern approaches to understand an old disease

Syphilis is a fascinating and perplexing infection, with protean clinical manifestations and both diagnostic and management ambiguities. Treponema pallidum subsp. pallidum, the agent of syphilis, is challenging to study in part because it cannot be cultured or genetically manipulated. Here, we review recent progress in the application of modern molecular techniques to understanding the biological basis of this multistage disease and to the development of new tools for diagnosis, for predicting efficacy of treatment with alternative antibiotics, and for studying the transmission of infection through population networks.

Predictors of serological cure and Serofast State after treatment in HIV-negative persons with early syphilis

BACKGROUND

Syphilis management requires serological monitoring after therapy. We compared factors associated with serological response after treatment of early (ie, primary, secondary, or early latent) syphilis.

METHODS

We performed secondary analyses of data from a prospective, randomized syphilis trial conducted in the United States and Madagascar. Human immunodeficiency virus (HIV)-negative participants aged ≥ 18 years with early syphilis were enrolled from 2000-2009. Serological testing was performed at baseline and at 3 and 6 months after treatment. At 6 months, serological cure was defined as a negative rapid plasma reagin (RPR) test or a ≥4-fold decreased titer, and serofast status was defined as a ≤ 2-fold decreased titer or persistent titers that did not meet criteria for treatment failure.

RESULTS

Data were available from 465 participants, of whom 369 (79%) achieved serological cure and 96 (21%) were serofast. In bivariate analysis, serological cure was associated with younger age, fewer sex partners, higher baseline RPR titers, and earlier syphilis stage (P ≤ .008). There was a less significant association with Jarisch-Herxheimer reaction after treatment (P = .08). Multivariate analysis revealed interactions between log-transformed baseline titer with syphilis stage, in which the likelihood of cure was associated with increased titers among participants with primary syphilis (adjusted odds ratio [AOR] for 1 unit change in log(2) titer, 1.83; 95% confidence interval [CI], 1.25-2.70), secondary syphilis (AOR, 3.15; 95% CI, 2.14-4.65), and early latent syphilis (AOR, 1.86; 95% CI, 1.44-2.40).

CONCLUSIONS

Serological cure at 6 months after early syphilis treatment is associated with age, number of sex partners, Jarisch-Herxheimer reaction, and an interaction between syphilis stage and baseline RPR titer.

Review of macrolides (azithromycin, clarithromycin), ketolids (telithromycin) and glycylcyclines (tigecycline)

The advanced macrolides, azithromycin and clarithromycin, and the ketolide, telithromycin, are structural analogs of erythromycin. They have several distinct advantages when compared with erythromycin, including enhanced spectrum of activity, more favorable pharmacokinetics and pharmacodynamics, once-daily administration, and improved tolerability. Clarithromycin and azithromycin are used extensively for the treatment of respiratory tract infections, sexually transmitted diseases, and Helicobacter pylori-associated peptic ulcer disease. Telithromycin is approved for the treatment of community-acquired pneumonia. Severe hepatotoxicity has been reported with the use of telithromycin.

The intersection between HIV and syphilis in men who have sex with men: some fresh perspectives

Syphilis is increasing in men who have sex with men and disproportionately affects HIV-infected men. Here we review the epidemiology, diagnostic techniques, treatment guidelines, follow-up procedures and control of syphilis. The difference in these factors in HIV-infected men and uninfected men and evidence for this is reviewed. We explain that HIV-infected men are at higher risk of syphilis acquisition as a result of different behavioral factors. Thus, some control strategies may be different for HIV-infected men owing to these factors and also because HIV-infected men are more closely linked with medical care. There is no strong evidence to suggest there should be any differences in diagnostic techniques, treatment guidelines or follow-up procedures between HIV-infected and uninfected men.

Notifying partners of patients with early syphilis in Madagascar: case-finding effectiveness and public health implications

OBJECTIVE

To evaluate the case-finding effectiveness of a clinic-based partner notification effort for early syphilis in Madagascar.

METHODS

We asked index cases who had proven early syphilis to identify and provide contact information of recent sex partners (in the past 3, 6, and 12 months for primary, secondary, and early latent syphilis, respectively). Named sex partners were contacted by index cases (patient notification) or, if approved by the index case, clinic staff members (provider notification); notified of their potential exposure to syphilis; and asked to come to the clinic for evaluation. We assessed case-finding effectiveness and calculated the 'brought-to-treatment' index (number of newly-diagnosed syphilis cases per number of index cases interviewed).

RESULTS

Of 565 index cases, 534 reported recent sex with at least one sex partner. A total of 3167 sex partners were reported, of whom 276 were contactable (9% of 3167). Providers notified 76% and cases notified 24% of these partners. 270 partners were contacted (98% of 276), and of these, 199 presented to the clinic for evaluation (74% of 270). A total of 99 partners tested positive for syphilis and received treatment (50% of 199). The 'brought-to-treatment' index was 0.18 (99 diagnoses per 565 index cases).

CONCLUSION

Partner notification was possible in this setting, resulting in treatment of syphilis-infected individuals who otherwise would likely have remained untreated. However, given <10% of the partners reported by index cases were contactable; the results highlight the limitations of partner notification and the need for additional sexually transmitted infection control strategies.

Evaluation of azithromycin resistance in Treponema pallidum specimens from Madagascar

Treponema pallidum resistance to azithromycin has been documented in the US, Canada, and Ireland. We found no evidence of resistance to azithromycin in specimens from 141 patients with syphilitic lesions in Madagascar suggesting resistance is geographically isolated and supporting use of azithromycin as alternative treatment for early syphilis in Madagascar.