Effectiveness of syphilis treatment using azithromycin and/or benzathine penicillin in Rakai, Uganda

Syphilis Treatment: Systematic Review and Meta-Analysis Investigating Nonpenicillin Therapeutic Strategies

Background

Penicillin's long-standing role as the reference standard in syphilis treatment has led to global reliance. However, this dependence presents challenges, prompting the need for alternative strategies. We performed a systematic literature review and meta-analysis to evaluate the efficacy of these alternative treatments against nonneurological syphilis.

Methods

We searched MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane, Scopus, and Web of Science from database inception to 28 August 2023, and we included studies that compared penicillin or amoxicillin monotherapy to other treatments for the management of nonneurological syphilis. Our primary outcome was serological cure rates. Random-effect models were used to obtain pooled mean differences, and heterogeneity was assessed using the I2 test.

Results

Of 6478 screened studies, 27 met the inclusion criteria, summing 6710 patients. The studies were considerably homogeneous, and stratified analyses considering each alternative treatment separately revealed that penicillin monotherapy did not outperform ceftriaxone (pooled odds ratio, 1.66 [95% confidence interval, .97-2.84]; I2 = 0%), azithromycin (0.92; [.73-1.18]; I2 = 0%), or doxycycline (0.82 [.61-1.10]; I2 = 1%) monotherapies with respect to serological conversion.

Conclusions

Alternative treatment strategies have serological cure rates equivalent to penicillin, potentially reducing global dependence on this antibiotic.

Antibiotic overuse, poor antimicrobial stewardship, and low specificity of syndromic case management in a cross section of men with urethral discharge syndrome in Kampala, Uganda

OBJECTIVE

High prevalence of sexually transmitted infections (STIs) combined with poor antimicrobial stewardship are drivers of STI antimicrobial resistance (AMR) especially in resource-limited settings where syndromic case management (SCM) is the norm. We characterized patterns of antibiotic use prior to clinic attendance and study enrollment in Ugandan men with urethral discharge syndrome (UDS), evaluated in-clinic prescribing, and the performance characteristics of SCM.

METHODS

Participants were recruited from government clinics participating in an existing gonococcal surveillance program in Kampala, Uganda. Questionnaires including antimicrobial use prior to attendance, prior episodes of UDS, penile swabs, and blood samples were collected. Bivariable and multivariable logistic regression models were used to estimate odds ratios (OR) for preselected factors likely to be associated with antibiotic use. In-clinic antibiotic treatment data were extracted from clinical notes, and the performance of SCM against laboratory-based STI diagnoses was evaluated.

FINDINGS

Between October 2019 and November 2020, 100(40%) of 250 men with UDS reported taking antibiotics in the 14days prior to attending the clinic. Of these 210(84%) had at least one curable STI and 20% had a reactive point-of-care HIV test. Multivariable analysis demonstrated significant associations between recent antimicrobial use and duration of UDS symptoms <6 days (OR 2.98(95%CI 1.07,8.36), p = 0.038), and sex with women only (OR 0.08(95%CI 0.01,0.82),p = 0.038). The sensitivity of SCM ranged from 80.0% to 94.4%; specificity was low between 5.6% and 33.1%. The positive predictive value of SCM ranged from 2.4(95%CI 0.7,6.0) for trichomoniasis to 63.4(95%CI 56.5,69.9) for gonorrhea.

CONCLUSION

Pre-enrollment antibiotic use was common in this population at high risk of STI and HIV. Combined with the poor specificity of SCM for male UDS, extensive antibiotic use is a likely driver of STI-AMR in Ugandan men. Interventions to improve antimicrobial stewardship and deliver affordable diagnostics to augment SCM and decrease overtreatment of STI syndromes are required.

Mass drug administration of antibacterials: weighing the evidence regarding benefits and risks

Background

Mass drug administration (MDA) is a strategy to improve health at the population level through widespread delivery of medicine in a community. We surveyed the literature to summarize the benefits and potential risks associated with MDA of antibacterials, focusing predominantly on azithromycin as it has the greatest evidence base.

Main body

High-quality evidence from randomized controlled trials (RCTs) indicate that MDA-azithromycin is effective in reducing the prevalence of infection due to yaws and trachoma. In addition, RCTs suggest that MDA-azithromycin reduces under-five mortality in certain low-resource settings that have high childhood mortality rates at baseline. This reduction in mortality appears to be sustained over time with twice-yearly MDA-azithromycin, with the greatest effect observed in children < 1 year of age. In addition, observational data suggest that infections such as skin and soft tissue infections, rheumatic heart disease, acute respiratory illness, diarrheal illness, and malaria may all be treated by azithromycin and thus incidentally impacted by MDA-azithromycin. However, the mechanism by which MDA-azithromycin reduces childhood mortality remains unclear. Verbal autopsies performed in MDA-azithromycin childhood mortality studies have produced conflicting data and are underpowered to answer this question. In addition to benefits, there are several important risks associated with MDA-azithromycin. Direct adverse effects potentially resulting from MDA-azithromycin include gastrointestinal side effects, idiopathic hypertrophic pyloric stenosis, cardiovascular side effects, and increase in chronic diseases such as asthma and obesity. Antibacterial resistance is also a risk associated with MDA-azithromycin and has been reported for both gram-positive and enteric organisms. Further, there is the risk for cross-resistance with other antibacterial agents, especially clindamycin.

Conclusions

Evidence shows that MDA-azithromycin programs may be beneficial for reducing trachoma, yaws, and mortality in children < 5 years of age in certain under-resourced settings. However, there are significant potential risks that need to be considered when deciding how, when, and where to implement these programs. Robust systems to monitor benefits as well as adverse effects and antibacterial resistance are warranted in communities where MDA-azithromycin programs are implemented.

Graphical Abstract

Treponema pallidum macrolide resistance and molecular epidemiology in southern Africa, 2008-2018

Treponema pallidum macrolide resistance and clinical treatment failure have emerged rapidly within communities where macrolides have been used as convenient, oral therapeutic alternatives to benzathine penicillin G for syphilis, or for other clinical indications. Macrolides are not included in the South African syndromic management guidelines for genital ulcer disease; however, in 2015, a 1 gram dose of azithromycin was incorporated into treatment algorithms for genital discharge. We determined the prevalence of 23S rRNA macrolide resistance-associated point mutations in 135 T. pallidum-positive surveillance specimens from Botswana, Zimbabwe and South Africa between 2008 and 2018. Additionally, we investigated the association between macrolide resistance, T. pallidum strain type and HIV co-infection. A significant increase in the prevalence of the A2058G macrolide resistance-associated point mutation was observed in specimens collected after 2015. There was a high level of molecular heterogeneity among T. pallidum strains circulating in the study communities, with strain type 14d/f being the most predominant in South Africa. Fourteen novel strain types, derived from three new tpr-gene restriction fragment length polymorphism patterns and seven new tp0548-gene sequence types, were identified. There was an association between A2058G-associated macrolide resistance and T. pallidum strain types 14d/f and 14d/g, but no association between T. pallidum macrolide resistance and HIV co-infection. The majority of T. pallidum strains, as well as strains containing the A2058G mutation, belonged to the SS14-like clade. This is the first study to extensively detail the molecular epidemiology and emergence of macrolide resistance in T. pallidum in southern Africa.

Prevalence of macrolide resistance in Treponema pallidum is associated with macrolide consumption

We hypothesized that the large global variations in the prevalence of macrolide resistance in Treponema pallidum are related to differences in population-level macrolide consumption. The hypothesis was tested by, at a country-level, regressing the peak prevalence of macrolide resistance against the national macrolide consumption in the year prior to this, controlling for the year of the resistance prevalence estimate. A strong association was found between the per capita consumption of macrolides and macrolide resistance (coefficient 0.7, 95 % confidence interval 0.2-0.12, P=0.009).

Trends in the relative prevalence of genital ulcer disease pathogens and association with HIV infection in Johannesburg, South Africa, 2007-2015

Background

In South Africa, treatment of genital ulcer disease (GUD) occurs in the context of syndromic management. GUD aetiological studies have been conducted in Johannesburg since 2007. We report on GUD pathogen prevalence, sero-prevalence of STI co-infections and aetiological trends among GUD patients presenting to a community-based primary healthcare facility in Johannesburg over a 9-year period.

Methods and findings

GUD surveys were conducted from January to April each year. Consecutive genital ulcers were sampled from consenting adults. Swab-extracted DNA was tested by multiplex real-time PCR assays for herpes simplex virus (HSV), Treponema pallidum (TP), Haemophilus ducreyi (HD) and Chlamydia trachomatis (CT). HSV-positive DNA extracts were further subtyped into HSV-1 and HSV-2 using a commercial PCR assay; CT-positive extracts were tested with an in-house PCR assay specific for serovars L1-L3 (lymphogranuloma venereum). Sera were tested for HIV, HSV-2, and syphilis co-infections. Giemsa-stained ulcer smears were screened for Klebsiella granulomatis by microscopy. Data were analysed with STATA^TM version 14. Of 771 GUD specimens, 503 (65.2%) had a detectable pathogen: HSV 468 (60.7%); TP 30 (3.9%); CT L1-3 7 (0.9%); HD 4 (0.5%). No aetiological agents were detected in 270 (34.8%) ulcer specimens. Seroprevalence rates were as follows: HIV 61.7%; HSV-2 80.2% and syphilis 5.8%. There was a strong association between GUD pathogen detection and HIV seropositivity (p < 0.001); 68% of cases caused by HSV were co-infected with HIV. There was a significant decline in the relative prevalence of ulcer-derived HSV over time, predominantly from 2013–2015 (p-value for trend = 0.023); and a trend towards a decrease in the HIV seropositivity rate (p-value for trend = 0.209).

Conclusions

HSV remains the leading cause of pathogen-detectable GUD in South Africa. The prevalence of HIV co-infection among GUD patients is high, underlining the importance of linkage to universal HIV testing and treatment in primary healthcare settings.

Molecular Typing of Syphilis-Causing Strains Among Human Immunodeficiency Virus-Positive Patients in Antwerp, Belgium

Centers for Disease Control and Prevention and sequencing-based treponeme typing was used to analyze 72 blood samples, collected from human immunodeficiency virus and syphilis co-infected patients during 2014 to 2015 in Antwerp, Belgium. Twenty-nine (40.3%) isolates were polymerase chain reaction positive for Treponema pallidum, and all tested were macrolide-resistant. Four genotypes were identified by sequencing-based typing including two new genotypes, U4NR8 and SU9R8, whereas enhanced Centers for Disease Control and Prevention typing revealed 7 subtypes.

Syphilis: Re-emergence of an old foe

Syphilis is caused by infection with Treponema pallidum subsp. pallidum, a not-yet-cultivable spiral-shaped bacterium that is usually transmitted by sexual contact with an infected partner or by an infected pregnant woman to her fetus. There is no vaccine to prevent syphilis. Diagnosis and treatment of infected individuals and their contacts is key to syphilis control programs that also include sex education and promotion of condom use to prevent infection. Untreated syphilis can progress through four stages: primary (chancre, regional lymphadenopathy), secondary (disseminated skin eruptions, generalized lymphadenopathy), latent (decreased re-occurrence of secondary stage manifestations, absence of symptoms), and tertiary (gummas, cardiovascular syphilis and late neurological symptoms). The primary and secondary stages are the most infectious. WHO estimates that each year 11 million new cases of syphilis occur globally among adults aged 15-49 years. Syphilis has re-emerged in several regions including North America, Western Europe, China and Australia. Host-associated factors that drive the re-emergence and spread of syphilis include high-risk sexual activity, migration and travel, and economic and social changes that limit access to health care. Early, uncomplicated syphilis is curable with a single intramuscular injection of benzathine penicillin G (BPG), the first line drug for all stages of syphilis. Emergence of macrolide-resistant T. pallidum has essentially precluded the empirical use of azithromycin as a second-line drug for treatment of syphilis. Virulence attributes of T. pallidum are poorly understood. Genomic and proteomic studies have provided some new information concerning how this spirochete may evade host defense mechanisms to persist for long periods in the host.

Comparison of serological responses to single-dose azithromycin (2 g) versus benzathine penicillin G in the treatment of early syphilis in HIV-infected patients in an area of low prevalence of macrolide-resistant Treponema pallidum infection

OBJECTIVES

Effectiveness of single-dose azithromycin (2 g) in the treatment of early syphilis among HIV-infected patients has rarely been evaluated in the era of combination ART.

METHODS

Consecutive HIV-infected patients with early syphilis, who received 2 g single-dose azithromycin or 2.4 MU benzathine penicillin G, between 2007 and 2014, were prospectively observed. Genotypic resistance to macrolides was determined in Treponema pallidum isolates identified from clinical specimens using PCR assays. Rapid plasma reagin (RPR) titres were determined at baseline and every 3 months after treatment. Primary outcome was a decline of RPR titre by ≥4-fold at 12 months after treatment.

RESULTS

During the study period, 162 HIV-infected patients with early syphilis received benzathine penicillin G and 237 patients received azithromycin. At 12 months follow-up, the serological response rate for penicillin and azithromycin groups was 61.1% and 56.5% (P = 0.41), respectively; respective response rate was 61.1% and 65.9% (P = 0.49) if we only included patients infected with T. pallidum not harbouring macrolide resistance in the azithromycin group. In multivariate analysis, RPR titres ≥1:32 (OR 2.56; 95% CI 1.55-4.21) and prior syphilis (OR 0.54; 95% CI 0.35-0.81) were predictors of serological response. Most common adverse effects of azithromycin included diarrhoea (52.7%), nausea (22.4%), abdominal pain (18.6%), bloating (17.7%) and lassitude/somnolence (27.4%).

CONCLUSIONS

In the setting of a low prevalence of macrolide-resistant T. pallidum, 2 g single-dose azithromycin achieved a similar serological response to benzathine penicillin G in HIV-infected patients with early syphilis. Major adverse effects of azithromycin were gastrointestinal symptoms and lassitude/somnolence.

Macrolide Resistance in the Syphilis Spirochete, Treponema pallidum ssp. pallidum: Can We Also Expect Macrolide-Resistant Yaws Strains?

Treponema pallidum ssp. pallidum (TPA) causes over 10 million new cases of syphilis worldwide whereas T. pallidum ssp. pertenue (TPE), the causative agent of yaws, affects about 2.5 million people. Although penicillin remains the drug of choice in the treatment of syphilis, in penicillin-allergic patients, macrolides have been used in this indication since the 1950s. Failures of macrolides in syphilis treatment have been well documented in the literature and since 2000, there has been a dramatic increase in a number of clinical samples with macrolide-resistant TPA. Scarce data regarding the genetics of macrolide-resistant mutations in TPA suggest that although macrolide-resistance mutations have emerged independently several times, the increase in the proportion of TPA strains resistant to macrolides is mainly due to the spread of resistant strains, especially in developed countries. The emergence of macrolide resistance in TPA appears to require a two-step process including either A2058G or A2059G mutation in one copy of the 23S rRNA gene and a subsequent gene conversion unification of both rRNA genes. Given the enormous genetic similarity that was recently revealed between TPA and TPE strains, there is a low but reasonable risk of emergence and spread of macrolide-resistant yaws strains following azithromycin treatment.

The molecular epidemiology of Treponema pallidum subspecies pallidum

Pathogens adapt and evolve in response to pressures exerted by host environments, leading to generation of genetically diverse variants. Treponema pallidum subspecies pallidum displays a substantial amount of interstrain diversity. These variants have been identified in various parts of the world, indicating transmission linkage between geographical regions. Genotyping is based on molecular characterisation of various loci in the syphilis treponeme genome, but still require further development and continued research, as new bacterial types are continually being detected. The goal for studying the molecular epidemiology of Treponema pallidum variants is the global monitoring of the transmission of genetically distinct organisms with different drug sensitivities and, potentially, different virulence proprieties.

High frequency of the 23S rRNA A2058G mutation of Treponema pallidum in Shanghai is associated with a current strategy for the treatment of syphilis

The preferred drugs for the treatment of syphilis, benzathine and procaine penicillin, have not been available in Shanghai for many years, and currently, the incidence of syphilis is increasing. Alternative antibiotics for patients with syphilis during the benzathine and procaine penicillin shortage include macrolides. The failure of macrolide treatment in syphilis patients has been reported in Shanghai, but the reason for this treatment failure remains unclear. We used polymerase chain reaction technology to detect a 23S rRNA A2058G mutation in Treponema pallidum in 109 specimens from syphilis patients. The use of azithromycin/erythromycin in the syphilis patients and the physicians' prescription habits were also assessed based on two questionnaires regarding the use of macrolides. A total of 104 specimens (95.4%) were positive for the A2058G mutation in both copies of the 23S rRNA gene, indicating macrolide resistance. A questionnaire provided to 122 dermatologists showed that during the penicillin shortage, they prescribed erythromycin and azithromycin for 8.24±13.95% and 3.21±6.37% of their patients, respectively, and in the case of penicillin allergy, erythromycin and azithromycin were prescribed 15.24±22.89% and 7.23±16.60% of the time, respectively. A second questionnaire provided to the syphilis patients showed that 150 (33.7%), 106 (23.8%) and 34 (7.6%) individuals had used azithromycin, erythromycin or both, respectively, although the majority did not use the drugs for syphilis treatment. Our findings suggest that macrolide resistance in Treponema pallidum is widespread in Shanghai. More than half of the syphilis patients had a history of macrolide use for other treatment purposes, which may have led to the high prevalence of macrolide resistance. Physicians in China are advised to not use azithromycin for early syphilis.

Treatment of syphilis: a systematic review

IMPORTANCE

The incidence of syphilis in the United States is increasing; it is estimated that more than 55,000 new infections will occur in 2014. Treatment regimens are controversial, especially in specific populations, and assessing treatment response based on serology remains a challenge.

OBJECTIVE

To review evidence regarding penicillin and nonpenicillin regimens, implications of the "serofast state," and treatment of specific populations including those with neurosyphilis or human immunodeficiency virus (HIV) infection and pregnant women.

EVIDENCE REVIEW

We searched MEDLINE for English-language human treatment studies dating from January 1965 until July 2014. The American Heart Association classification system was used to rate quality of evidence.

FINDINGS

We included 102 articles in our review, consisting of randomized trials, meta-analyses, and cohort studies. Case reports and small series were excluded unless they were the only studies providing evidence for a specific treatment strategy. We included 11 randomized trials. Evidence regarding penicillin and nonpenicillin regimens was reviewed from studies involving 11,102 patients. Data on the treatment of early syphilis support the use of a single intramuscular injection of 2.4 million U of benzathine penicillin G, with studies reporting 90% to 100% treatment success rates. The value of multiple-dose treatment of early syphilis is uncertain, especially in HIV-infected individuals. Less evidence is available regarding therapy for late and late latent syphilis. Following treatment, nontreponemal serologic titers should decline in a stable pattern, but a significant proportion of patients may remain seropositive (the "serofast state"). Serologic response to treatment should be evident by 6 months in early syphilis but is generally slower (12-24 months) for latent syphilis. Evidence defining treatment for HIV-infected persons and for pregnant women is limited, but available data support penicillin as first-line therapy.

CONCLUSIONS AND RELEVANCE

The mainstay of syphilis treatment is parenteral penicillin G despite the relatively modest clinical trial data that support its use.

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.

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.

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.

Developments in therapy and diagnosis of yaws and future prospects

Yaws, a chronic and debilitating infectious disease caused by Treponema pallidum subsp. pertenue, and closely related to syphilis, although transmitted by skin-to-skin contact, remains an important public health challenge, causing a significant burden of morbidity in children in certain areas of the Pacific and Africa. Recent advances in its diagnosis and treatment have led to an enthusiastic upsurge of activities related to its control, and exciting perspectives of global eradication. Although possibly considered among the most neglected of all neglected diseases during decades, there seems to be now agreement that massive drug administration of the antibiotic azithromycin, coupled with adequate surveillance of foci of transmission could result in its eradication. In this review, we summarize current knowledge regarding the therapeutics of yaws and its diagnosis.

Yaws

Yaws is an infectious disease caused by Treponema pallidum pertenue-a bacterium that closely resembles the causative agent of syphilis-and is spread by skin-to-skin contact in humid tropical regions. Yaws causes disfiguring, and sometimes painful lesions of the skin and bones. As with syphilis, clinical manifestations can be divided into three stages; however, unlike syphilis, mother-to-child transmission does not occur. A major campaign to eradicate yaws in the 1950s and 1960s, by mass treatment of affected communities with longacting, injectable penicillin, reduced the number of cases by 95% worldwide, but yaws has reappeared in recent years in Africa, Asia, and the western Pacific. In 2012, one oral dose of azithromycin was shown to be as effective as intramuscular penicillin in the treatment of the disease, and WHO launched a new initiative to eradicate yaws by 2020.

Detection of the A2058G and A2059G 23S rRNA gene point mutations associated with azithromycin resistance in Treponema pallidum by use of a TaqMan real-time multiplex PCR assay

Macrolide treatment failure in syphilis patients is associated with a single point mutation (either A2058G or A2059G) in both copies of the 23S rRNA gene in Treponema pallidum strains. The conventional method for the detection of both point mutations uses nested PCR combined with restriction enzyme digestions, which is laborious and time-consuming. We initially developed a TaqMan-based real-time duplex PCR assay for detection of the A2058G mutation, and upon discovery of the A2059G mutation, we modified the assay into a triplex format to simultaneously detect both mutations. The point mutations detected by the real-time triplex PCR were confirmed by pyrosequencing. A total of 129 specimens PCR positive for T. pallidum that were obtained from an azithromycin resistance surveillance study conducted in the United States were analyzed. Sixty-six (51.2%) of the 129 samples with the A2058G mutation were identified by both real-time PCR assays. Of the remaining 63 samples that were identified as having a macrolide-susceptible genotype by the duplex PCR assay, 17 (27%) were found to contain the A2059G mutation by the triplex PCR. The proportions of macrolide-susceptible versus -resistant genotypes harboring either the A2058G or the A2059G mutation among the T. pallidum strains were 35.6, 51.2, and 13.2%, respectively. None of the T. pallidum strains examined had both point mutations. The TaqMan-based real-time triplex PCR assay offers an alternative to conventional nested PCR and restriction fragment length polymorphism analyses for the rapid detection of both point mutations associated with macrolide resistance in T. pallidum.

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.

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.

Congenital syphilis in the 21st century

While the prevalence of congenital syphilis continues to be low throughout most of the developed world, there has been a slight resurgence of the disease in several European countries, including Spain. In this context, we need to become more familiar with the signs and symptoms of this disease and consider its diagnosis in patients with only mild clinical manifestations. A definitive diagnosis may be difficult or even impossible in patients whose diagnostic tests reveal low positive titers or inconsistent results. The cornerstone of congenital syphilis control is prenatal screening and the treatment of infected mothers with penicillin, an effective and economical intervention. Based on a review of the literature supplemented by data from our own clinical experience, this article provides a detailed description of the clinical manifestations of congenital syphilis as well as the various diagnostic methods and treatments available.

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.

Molecular typing of Treponema pallidum: a systematic review and meta-analysis

BACKGROUND

Syphilis is resurgent in many regions of the world. Molecular typing is a robust tool for investigating strain diversity and epidemiology. This study aimed to review original research on molecular typing of Treponema pallidum (T. pallidum) with three objectives: (1) to determine specimen types most suitable for molecular typing; (2) to determine T. pallidum subtype distribution across geographic areas; and (3) to summarize available information on subtypes associated with neurosyphilis and macrolide resistance.

METHODOLOGY/PRINCIPAL FINDINGS

Two researchers independently searched five databases from 1998 through 2010, assessed for eligibility and study quality, and extracted data. Search terms included "Treponema pallidum," or "syphilis," combined with the subject headings "molecular," "subtyping," "typing," "genotype," and "epidemiology." Sixteen eligible studies were included. Publication bias was not statistically significant by the Begg rank correlation test. Medians, inter-quartile ranges, and 95% confidence intervals were determined for DNA extraction and full typing efficiency. A random-effects model was used to perform subgroup analyses to reduce obvious between-study heterogeneity. Primary and secondary lesions and ear lobe blood specimens had an average higher yield of T. pallidum DNA (83.0% vs. 28.2%, χ(2) = 247.6, p<0.001) and an average higher efficiency of full molecular typing (80.9% vs. 43.1%, χ(2) = 102.3, p<0.001) compared to plasma, whole blood, and cerebrospinal fluid. A pooled analysis of subtype distribution based on country location showed that 14d was the most common subtype, and subtype distribution varied across geographic areas. Subtype data associated with macrolide resistance and neurosyphilis were limited.

CONCLUSIONS/SIGNIFICANCE

Primary lesion was a better specimen for obtaining T. pallidum DNA than blood. There was wide geographic variation in T. pallidum subtypes. More research is needed on the relationship between clinical presentation and subtype, and further validation of ear lobe blood for obtaining T. pallidum DNA would be useful for future molecular studies of syphilis.

Hepatitis B virus and sexual behavior in Rakai, Uganda

HIV and hepatitis B virus (HBV) co-infection poses important public health considerations in resource-limited settings. Demographic data and sera from adult participants of the Rakai Health Sciences Program Cohort in Southwestern Uganda were examined to determine HBV seroprevalence patterns in this area of high HIV endemicity prior to the introduction of anti-retroviral therapy. Commercially available EIAs were used to detect prevalent HBV infection (positive for HBV core antibody [anti-HBc] and/or positive HBV surface antigen [HBsAg]), and chronic infection (positive for HBsAg). Of 438 participants, 181 (41%) had prevalent HBV infection while 21 (5%) were infected chronically. Fourteen percent of participants were infected with HIV. Fifty three percent showed evidence of prevalent HBV infection compared to 40% among participants infected with HIV (P = 0.067). Seven percent of participants infected with HIV were HBsAg positive compared to 4% among participants not infected with HIV (P = 0.403). The prevalence of prevalent HBV infection was 55% in adults aged >50 years old, and 11% in persons under 20 years. In multivariable analysis, older age, HIV status, and serologic syphilis were significantly associated with prevalent HBV infection. Transfusion status and receipt of injections were not significantly associated with HBV infection. Contrary to expectations that HBV exposure in Uganda occurred chiefly during childhood, prevalent HBV infection was found to increase with age and was associated sexually transmitted diseases (HIV and syphilis.) Therefore vaccination against HBV, particularly susceptible adults with HIV or at risk of HIV/STDs should be a priority.

Intermittent preventive treatment of malaria in pregnancy: at the crossroads of public health policy

The intermittent preventive treatment of malaria in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) has been a key component of the focused antenatal care package for nearly a decade, reducing the burden of low birthweight attributable to malaria in sub-Saharan Africa. However, SP has lost parasite sensitivity in many sub-Saharan locations during the same period, rendering its beneficial effect in IPTp debatable. Malaria transmission has also declined in some epidemiological settings. There is no evidence to suggest, however, that the risk of malaria in pregnancy without preventive measures has declined in the same locations. Thus, the urgency to identify efficacious drugs and/or new strategies to prevent malaria in pregnancy remains as great as ever. We summarise the results of recently published SP-IPTp studies from areas of high drug resistance and/or low malaria transmission. We also present the evidence for mefloquine and azithromycin-based combinations (ABCs), two leading drug options to replace SP in IPTp. We discuss optimal dosing for ABCs and their likely protection against several sexually transmitted and reproductive tract infections. We also summarise data from a diagnosis-based alternative to IPTp known as the intermittent screening and treatment (IST) for malaria. Clinical and operational research is urgently needed to compare birth outcomes achieved by IPTp with ABCs vs. IST using an efficacious antimalarial therapy.

Azithromycin treatment failure among primary and secondary syphilis patients in Shanghai

BACKGROUND

Azithromycin has been used to treat primary and secondary syphilis and as prophylaxis for sexual partners. We evaluated syphilis treatment failure in patients who received azithromycin therapy.

METHODS

Patients who did not respond to azithromycin therapy were referred to Shanghai Skin Disease and sexually transmitted disease hospital. Treatment failure was defined as follows: (1) persistent ulcers or cutaneous or mucosal lesions 1 month after therapy; or (2) detection of spirochetes in dark-field microscopy examination of a lesion at least 1 week after treatment; or (3) failure of rapid plasma reagin titers to decrease 4-fold at 3 months after treatment.

RESULTS

A total of 132 patients with primary and secondary syphilis who failed azithromycin therapy were referred to our hospital between January 2001 and October 2008. Of 132 patients, 42 (31.8%) had primary syphilis and 90 (68.2%) had secondary syphilis. Twenty-six patients with primary syphilis developed multiple lesions or secondary syphilis, or persistent ulcers despite using azithromycin. The skin or mucosal lesions did not resolve in 37 patients with secondary syphilis after azithromycin treatment. Ten patients had a positive dark-field examination for Treponema pallidum (T. pallidum) after treatment. The serum rapid plasma reagin titers studied in all cases had failed to decrease 4-fold at 3 months after therapy. The doses of azithromycin used for treatment ranged from 4 to 30 g.

CONCLUSIONS

The failure of azithromycin to cure a substantial number of patients with primary and secondary syphilis in Shanghai suggests that azithromycin has limited therapeutic value in this setting.

Syphilis and HIV co-infection in an Israeli HIV clinic: incidence and outcome

The re-emergence of syphilis among HIV-infected patients has been reported in recent years. We evaluated co-infection among heterosexual immigrants in an Israeli AIDS center. The records of 1060 HIV-infected patients were evaluated for positive syphilis serology between the years 2000 and 2005, and all seropositive patients were further evaluated. We found 150 HIV/syphilis co-infected patients (57% men, 93% of African origin), of who 135 were found to have late latent syphilis. Lumbar puncture (LP) was performed in 51 patients, 16 (31%) had abnormal cerebrospinal fluid (CSF) compatible with neurosyphilis. Abnormal CSF correlated with the absence of previous anti-syphilis treatment, but not with CD4 count, viral load or Venereal Disease Research Laboratory titres. Penicillin was recommended to all patients according to their disease stages and 81 patients completed 12 months post-treatment follow-up. Twenty-one of 81 (26%) treatments were successful, 33 (41%) showed 'serofast reaction' and 27 (33%) failed therapy. In conclusion, a high incidence of syphilis with CSF reactivity suggestive of neurosyphilis was observed in heterosexual Ethiopian HIV-infected patients. Thus, repeated serological screening and CSF evaluation seems to be indicated in these patients. Penicillin therapy resulted in 'serofast reaction' or treatment failure for most patients. More, intensive treatment might be needed for HIV/syphilis in co-infected patients, especially those with severe immune-deficiency and prolonged syphilis infection.

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.

Global challenge of antibiotic-resistant Treponema pallidum

Syphilis is a multistage infectious disease that is usually transmitted through contact with active lesions of a sexual partner or from an infected pregnant woman to her fetus. Despite elimination efforts, syphilis remains endemic in many developing countries and has reemerged in several developed countries, including China, where a widespread epidemic recently occurred. In the absence of a vaccine, syphilis control is largely dependent upon identification of infected individuals and treatment of these individuals and their contacts with antibiotics. Although penicillin is still effective, clinically significant resistance to macrolides, a second-line alternative to penicillin, has emerged. Macrolide-resistant strains of Treponema pallidum are now prevalent in several developed countries. An understanding of the genetic basis of T. pallidum antibiotic resistance is essential to enable molecular surveillance. This review discusses the genetic basis of T. pallidum macrolide resistance and the potential of this spirochete to develop additional antibiotic resistance that could seriously compromise syphilis treatment and control.

Macrolide treatment failure in a case of secondary syphilis: a novel A2059G mutation in the 23S rRNA gene of Treponema pallidum subsp. pallidum

We report an occurrence of treatment failure after oral spiramycin therapy in a man with secondary syphilis and a reported penicillin and tetracycline allergy. Molecular detection revealed treponemal DNA in the blood of the patient and sequencing of the 23S rDNA identified an A to G transition at the gene position corresponding to position 2059 in the Escherichia coli 23S rRNA gene. The occurrence of this novel 23S rDNA mutation was examined among 7 rabbit-propagated syphilitic strains of Treponema pallidum and among 22 syphilis patient isolates from the Czech Republic. The prevalence of A2058G and A2059G mutations among clinical specimens was 18.2 and 18.2 %, respectively.

Azithromycin-chloroquine and the intermittent preventive treatment of malaria in pregnancy

In the high malaria-transmission settings of sub-Saharan Africa, malaria in pregnancy is an important cause of maternal, perinatal and neonatal morbidity. Intermittent preventive treatment of malaria in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) reduces the incidence of low birth-weight, pre-term delivery, intrauterine growth-retardation and maternal anaemia. However, the public health benefits of IPTp are declining due to SP resistance. The combination of azithromycin and chloroquine is a potential alternative to SP for IPTp. This review summarizes key in vitro and in vivo evidence of azithromycin and chloroquine activity against Plasmodium falciparum and Plasmodium vivax, as well as the anticipated secondary benefits that may result from their combined use in IPTp, including the cure and prevention of many sexually transmitted diseases. Drug costs and the necessity for external financing are discussed along with a range of issues related to drug resistance and surveillance. Several scientific and programmatic questions of interest to policymakers and programme managers are also presented that would need to be addressed before azithromycin-chloroquine could be adopted for use in IPTp.

Azithromycin vs. benzathine penicillin G for early syphilis: a meta-analysis of randomized clinical trials

The World Health Organization estimates that at least 12 million people are infected with syphilis in the world. Southeast Asia accounts for 5.8 million; Africa accounts for 3.5 million. There has been controversy in using the two kinds of antibiotics for early syphilis. A systematic review comparing these antibiotics could affect treatment guidelines. The aim of this study was to evaluate the efficacy and safety of azithromycin vs. penicillin G benzathine for early syphilis and a meta-analysis to compare these two kinds of antibiotics for early syphilis. Four randomized controlled trials met the inclusion criteria; 476 patients were evaluated for their cure rate. Cure rates were 95.0% (227/239) for azithromycin and 84.0% (199/237) for penicillin G benzathine. After pooling the data, the difference in efficacy was computed. Cure rate (OR=1.37), 95% CI (1.05, 1.77) and the risk difference for cure rate between the two drugs were statistically significant. Although the gastrointestinal adverse effect of azithromycin is five times more than the adverse effect of penicillin G benzathine, the differences are not significant. Azithromycin achieved a higher cure rate than penicillin G benzathine in a long follow-up.

A consequence of the syphilis epidemic among men who have sex with men (MSM): neurosyphilis in Los Angeles, 2001-2004

OBJECTIVES

To describe the epidemiology and clinical findings of neurosyphilis (NS) cases diagnosed during the current syphilis epidemic occurring predominantly among men who have sex with men.

METHODS

Syphilis cases reported to the health department were reviewed for diagnosis of NS, cerebrospinal fluid venereal disease research laboratory results, and/or treatment for NS.

RESULTS

During 2001-2004, 7083 cases of syphilis were diagnosed in Los Angeles. One hundred nine cases of confirmed or probable NS occurring among persons aged 19 to 65 years were identified during this period (1.5%). Symptomatic NS was present in 1.2% of reported syphilis cases (86 of 7083). NS cases were inclusive of 71 (65%) men who have sex with men. Forty-two (49%) of the symptomatic NS cases occurred during secondary (N = 28) or early latent (N = 14) syphilis. Sixty-eight percent (N = 74) of the NS cases were human immunodeficiency virus (HIV)-positive. The estimated incidence of symptomatic NS among HIV-infected persons with early syphilis was 2.1% as compared with 0.6% among HIV-negative persons.

CONCLUSION

Providers should maintain a high index of suspicion for NS among patients with syphilis, particularly those with HIV infection.

Rights of HIV positive people to sexual and reproductive health: parenthood

In many areas of the globe most HIV infection is transmitted sexually or in association with pregnancy, childbirth and breastfeeding, raising the need for sexual and reproductive health and HIV/AIDS initiatives to be mutually reinforcing. Many people with HIV, who are in good health, will want to have children, and highly active antiretroviral therapy provides women and men living with AIDS the possibility of envisaging new life projects such as parenthood, because of a return to health. However, there are still difficult choices to face concerning sexuality, parenthood desires and family life. Structural, social and cultural issues, as well as the lack of programmatic support, hinder the fulfilment of the right to quality sexual and reproductive health care and support for having a family. This paper addresses the continuum of care involved in parenthood for people living with HIV, from pregnancy to infant and child care, and provides evidence-based examples of policies and programmes that integrate sexual and reproductive health interventions with HIV/AIDS care in order to support parenthood. Focusing on parenthood for people living with and affected by HIV, that is, focusing on the couple rather than the woman as the unit of care, the individual or the set of adults who are responsible for raising children, would be an innovative programmatic advance. Going beyond maternal and child health care to providing care and support for parents and others who are responsible for raising children is especially relevant for those living with HIV infection.

Congenital syphilis: a continuing but neglected problem

Congenital syphilis was rare in most affluent countries but there has been a slight resurgence recently in several European countries. In large parts of the world and particularly sub-Saharan Africa congenital syphilis is a significant public health problem. The cornerstone of congenital syphilis control is antenatal screening and treatment of mothers with penicillin, which is a cost-effective intervention. In affluent countries it should be strengthened among those at high risk. Clinicians should be more vigilant for the possibility of babies being born with congenital syphilis, which is often asymptomatic. In developing countries not only does antenatal care screening need to be strengthened by implementing point-of-care decentralised screening and treatment but alternative innovative approaches to controlling congenital syphilis should be explored. There is an urgent need for international health agencies to support focused approaches to tackling the tragedy of continuing congenital syphilis. This could be a part of a pro-poor strategy to meet the Millennium Development Goals.

Current Controversies in the Management of Adult Syphilis

Clinical management of patients with syphilis is controversial. This article summarizes recent research on syphilis treatment efficacy and outcomes and is based on a comprehensive systematic review of published literature, relevant abstracts, conference proceedings, technical reports, and guidelines. Penicillin remains the drug of choice for the treatment of syphilis. Although several studies have suggested that azithromycin may have clinical efficacy, macrolide resistance has been widely documented among strains of Treponema pallidum, and treatment failures have been reported. Ceftriaxone is effective for the treatment of syphilis when used in multiple-dose regimens. Lumbar puncture should be performed for human immunodeficiency virus-infected patients with syphilis of >1 year's duration and a serum nontreponemal test titer > or =1 : 32, as well for other patients for whom the clinical suspicion of neurosyphilis is high. Newer laboratory tests for syphilis are undergoing extensive evaluation and may prove to be useful for future clinical care. American and European approaches to syphilis treatment are similar, but they vary across several parameters.