Cephalosporin-resistant gonorrhea in North America

Priorities for sexually transmitted infection vaccine research and development: Results from a survey of global leaders and representatives

OBJECTIVE

To determine the sexually transmitted infection (STI) vaccine research priorities of global leaders in STI vaccine research, development, and service provision.

METHODS

Global representatives attending the STI Vaccines: Opportunities for Research, Development, and Implementation symposium preceding the STI & HIV World Congress in 2019 were invited to complete an electronic survey. We asked participants to rank items by importance/priority for STI vaccine development for the following areas of focus: specific STIs (gonorrhea, chlamydia, syphilis, herpes, and trichomoniasis), broad research domains (basic science, funding, communication, program planning, and vaccine hesitancy), and specific research activities related to these domains. We calculated weighted value scores based on the ranking (e.g., first, second, third) and the total number of responses in order to produce a ranked list of the priorities.

RESULTS

A total of 46 out of 97 (44%) symposium attendees responded to the survey. Gonorrhea was identified as the STI that should be prioritized for vaccine development, followed by syphilis with weighted value scores of 3.82 and 3.37, respectively, out of a maximum of five. Basic science (and vaccine development) was the domain ranked with the highest priority with a weighted value score of 4.78 out of six. Research activities related to basic science and vaccine development (including pre-clinical and clinical trials, and surveillance measures) and increased funding opportunities were the most highly ranked activities in the "STI vaccine development" and "research domains and activities" categories.

CONCLUSION

Global leaders in attendance at the STI Vaccines symposium prioritized continued scientific work in vaccine development and program planning. Gonorrhea was identified as the highest priority infection, followed by syphilis.

A Narrative Review of Clinical Treatment Outcomes of Neisseria gonorrhoeae Infection With Ciprofloxacin by Minimum Inhibitory Concentration and Anatomic Site

BACKGROUND

Neisseria gonorrhoeae infections are becoming increasingly resistant to recommended treatments. Resistance-guided therapy may mitigate the continued emergence of resistance by enabling the use of previously recommended treatments like ciprofloxacin. To describe the effectiveness of ciprofloxacin to treat "susceptible" infections, we estimated the clinical efficacy of ciprofloxacin at various minimum inhibitory concentrations (MICs) and anatomic sites.

METHODS

We reviewed publicly available reports using the PubMed.gov database and search terms "gonorrhea/drug therapy"[Mesh] AND "ciprofloxacin". We included clinical treatment studies in which ciprofloxacin was administered alone to treat N. gonorrhoeae, specimens were collected for N. gonorrhoeae culture from each infection, the MIC was determined for ≥90% of infective strains, and individual treatment outcomes were clearly defined. We recorded those data, ciprofloxacin dose and infection site. We calculated the frequency of treatment success and 95% confidence intervals (CIs).

RESULTS

Twenty studies from 1985 to 2020 met our inclusion criteria. Ciprofloxacin at commonly used doses eliminated 99.2% (95% CI, 98.5%-99.6%; n = 1439) of gonococcal infections with MICs <0.125 μg/mL, 76.3% (95% CI, 59.8%-88.6%; n = 38) of infections with MICs from 0.125 to 0.5 μg/mL, and 30.1% (95% CI, 20.5%-41.2%; n = 83) of infections with MICs ≥1 μg/mL across anatomic sites.

CONCLUSIONS

Ciprofloxacin reliably eliminated gonococcal infections with MICs <0.125 μg/mL across anatomic sites. Molecular assays predicting MICs of ciprofloxacin <0.125 μg/mL of gonococcal strains can allow for reintroduction of ciprofloxacin in gonorrhea treatment. Clinicians can confidently use ciprofloxacin to treat susceptible gonococcal infections.

Advancing vaccine development for gonorrhoea and the Global STI Vaccine Roadmap

Efforts to develop vaccines against Neisseria gonorrhoeae have become increasingly important, given the rising threat of gonococcal antimicrobial resistance (AMR). Recent data suggest vaccines for gonorrhoea are biologically feasible; in particular, epidemiological evidence shows that vaccines against a closely related pathogen, serogroup B Neisseria meningitidis outer membrane vesicle (OMV) vaccines, may reduce gonorrhoea incidence. Vaccine candidates using several approaches are currently in preclinical development, including meningococcal and gonococcal OMV vaccines, a lipooligosaccharide epitope and purified protein subunit vaccines. The Global STI Vaccine Roadmap provides action steps to build on this technical momentum and advance gonococcal vaccine development. Better quantifying the magnitude of gonorrhoea-associated disease burden, for outcomes like infertility, and modelling the predicted role of gonococcal vaccines in addressing AMR will be essential for building a full public health value proposition, which can justify investment and help with decision making about future vaccine policy and programs. Efforts are underway to gain consensus on gonorrhoea vaccine target populations, implementation strategies and other preferred product characteristics that would make these vaccines suitable for use in low- and middle-income, as well as high-income, contexts. Addressing these epidemiological, programmatic and policy considerations in parallel to advancing research and development, including direct assessment of the ability of meningococcal B OMV vaccines to prevent gonorrhoea, can help bring about the development of viable gonococcal vaccines.

Availability of Injectable Antimicrobial Drugs for Gonorrhea and Syphilis, United States, 2016

We estimated the availability of the injectable antimicrobial drugs recommended for point-of-care treatment of gonorrhea and syphilis among US physicians who evaluated patients with sexually transmitted infections in 2016. Most physicians did not have these drugs available on-site. Further research is needed to determine the reasons for the unavailability of these drugs.

Aminomethyl Spectinomycins as Therapeutics for Drug-Resistant Gonorrhea and Chlamydia Coinfections

Bacterial sexually transmitted infections are widespread and common, with Neisseria gonorrhoeae (gonorrhea) and Chlamydia trachomatis (chlamydia) being the two most frequent causes. If left untreated, both infections can cause pelvic inflammatory disease, infertility, ectopic pregnancy, and other sequelae. The recommended treatment for gonorrhea is ceftriaxone plus azithromycin (to empirically treat chlamydial coinfections). Antibiotic resistance to all existing therapies has developed in gonorrheal infections. The need for new antibiotics is great, but the pipeline for new drugs is alarmingly small. The aminomethyl spectinomycins, a new class of semisynthetic analogs of the antibiotic spectinomycin, were developed on the basis of a computational analysis of the spectinomycin binding site of the bacterial 30S ribosome and structure-guided synthesis. The compounds display particular potency against common respiratory tract pathogens as well as the sexually transmitted pathogens that cause gonorrhea and chlamydia. Here, we demonstrate the in vitro potencies of several compounds of this class against both bacterial species; the compounds displayed increased potencies against N. gonorrhoeae compared to that of spectinomycin and, significantly, demonstrated activity against C. trachomatis that is not observed with spectinomycin. Efficacies of the compounds were compared to those of spectinomycin and gentamicin in a murine model of infection caused by ceftriaxone/azithromycin-resistant N. gonorrhoeae; the aminomethyl spectinomycins significantly reduced the colonization load and were as potent as the comparator compounds. In summary, data produced by this study support aminomethyl spectinomycins as a promising replacement for spectinomycin and antibiotics such as ceftriaxone for treating drug-resistant gonorrhea, with the added benefit of treating chlamydial coinfections.

Assessing Different Partner Notification Methods for Assuring Partner Treatment for Gonorrhea: Looking for the Best Mix of Options

CONTEXT

Partner notification for gonorrhea is intended to interrupt transmission and to bring people exposed to infection to care. Partner notification may be initiated through public health professionals (disease intervention specialist: DIS referral) or patients (patient referral). In some cases, patients may carry medications or prescriptions for partners (patient-delivered partner therapy: PDPT).

OBJECTIVE

To examine how patterns of notifying and treating partners of persons with gonorrhea differ by partner notification approach.

DESIGN

From published literature (2005-2012), we extracted 10 estimates of patient referral data from 7 studies (3853 patients, 7490 partners) and 5 estimates of PDPT data from 5 studies (1781 patients, 3125 partners). For DIS referral estimates, we obtained 2010-2012 data from 14 program settings (4581 patients interviewed, 8301 partners). For each approach, we calculated treatment cascades based on the proportion of partners who were notified and treated. We also calculated cascades based on partners notified and treated per patient diagnosed.

RESULTS

Proportions of partners notified and treated were, for patient referral, 56% and 34%; for PDPT, 57% and 46%; for DIS referral, 25% and 22%. Notification and treatment estimates for patient referral and PDPT were significantly higher than for DIS referral, but DIS referral was more efficacious than the other methods in assuring treatment among those notified (all Ps < .001). The notification and treatment ratios per patient seen were, for patient referral, 0.96 and 0.61; for PDPT, 0.90 and 0.73; for DIS referral, 0.45 and 0.40.

CONCLUSION

Patient-based methods had higher proportions of partners treated overall, but provider referral had the highest proportion treated among those notified. These data may assist programs to align the most efficacious strategies with the most epidemiologically or clinically important cases while assuring the best scalable standard of care for others.

Sexually Transmitted Infection Review for the Acute Care Pharmacist

PURPOSE

Review selected sexually transmitted infections (STIs) and treatment recommendations for pharmacists and providers practicing in the acute care setting.

SUMMARY

In 2015, the Centers for Disease Control and Prevention (CDC) published an updated guideline on the treatment of STIs with an emphasis on prevention and new diagnostic strategies to combat the growing problem of STIs in the United States. Despite this guidance, the incidence of infection has continued to grow. In October 2016, an in-depth analysis reported that 20 million new infections occur annually in the United States. With this growing burden of disease, it is pertinent that health-care providers optimize their treatment strategies to improve upon the management of STIs. Focusing on identification of asymptomatic- and symptomatic-infected persons, treatment, education, effective follow-up, and counseling for patients and sexual partners, emergency medicine pharmacists and providers can help minimize the negative long-term health consequences of STIs.

CONCLUSION

In the emergency department setting, clinical pharmacists and providers can play a crucial role in preventing and treating STIs and should continue to expand and keep current their knowledge of this topic.

Developing New Antimicrobial Therapies: Are Synergistic Combinations of Plant Extracts/Compounds with Conventional Antibiotics the Solution?

The discovery of penicillin nearly 90 years ago revolutionized the treatment of bacterial disease. Since that time, numerous other antibiotics have been discovered from bacteria and fungi, or developed by chemical synthesis and have become effective chemotherapeutic options. However, the misuse of antibiotics has lessened the efficacy of many commonly used antibiotics. The emergence of resistant strains of bacteria has seriously limited our ability to treat bacterial illness, and new antibiotics are desperately needed. Since the discovery of penicillin, most antibiotic development has focused on the discovery of new antibiotics derived from microbial sources, or on the synthesis of new compounds using existing antibiotic scaffolds to the detriment of other lines of discovery. Both of these methods have been fruitful. However, for a number of reasons discussed in this review, these strategies are unlikely to provide the same wealth of new antibiotics in the future. Indeed, the number of newly developed antibiotics has decreased dramatically in recent years. Instead, a reexamination of traditional medicines has become more common and has already provided several new antibiotics. Traditional medicine plants are likely to provide further new antibiotics in the future. However, the use of plant extracts or pure natural compounds in combination with conventional antibiotics may hold greater promise for rapidly providing affordable treatment options. Indeed, some combinational antibiotic therapies are already clinically available. This study reviews the recent literature on combinational antibiotic therapies to highlight their potential and to guide future research in this field.

Committee Opinion No. 645: Dual Therapy for Gonococcal Infections

Gonorrhea is the second most commonly reported bacterial sexually transmitted disease in the United States, with an estimated 820,000 new Neisseria gonorrhoeae infections occurring each year. Antimicrobial resistance limits treatment success, heightens the risk of complications, and may facilitate the transmission of sexually transmitted infections. Neisseria gonorrhoeae has developed resistance to the sulfonamides, the tetracyclines, and penicillin. Dual therapy with ceftriaxone and azithromycin remains the only recommended first-line regimen for the treatment of gonorrhea in the United States. Dual therapy with ceftriaxone and azithromycin should be administered together on the same day, preferably simultaneously, and under direct observation. Pregnant women who are infected with N gonorrhoeae should be treated with the recommended dual therapy. A test-of-cure is not needed for individuals diagnosed with uncomplicated urogenital or rectal gonorrhea who are treated with the recommended or alternative regimens. Repeat N gonorrhoeae infection is prevalent among patients who have been diagnosed with and treated for gonorrhea in the preceding several months. Most of these infections result from reinfection; therefore, clinicians should advise patients with gonorrhea to be retested 3 months after treatment. Pregnant women with antenatal gonococcal infection should be retested in the third trimester unless recently treated.

Future prospects for new vaccines against sexually transmitted infections

PURPOSE OF REVIEW

This review provides an update on the need, development status, and important next steps for advancing development of vaccines against sexually transmitted infections (STIs), including herpes simplex virus (HSV), Neisseria gonorrhoeae (gonorrhea), Chlamydia trachomatis (chlamydia), and Treponema pallidum (syphilis).

RECENT FINDINGS

Global estimates suggest that more than a million STIs are acquired every day, and many new and emerging challenges to STI control highlight the critical need for development of new STI vaccines. Several therapeutic HSV-2 vaccine candidates are in Phase I/II clinical trials, and one subunit vaccine has shown sustained reductions in genital lesions and viral shedding, providing hope that an effective HSV vaccine is on the horizon. The first vaccine candidate for genital chlamydia infection has entered Phase I trials, and several more are in the pipeline. Use of novel technological approaches will likely see viable vaccine candidates for gonorrhea and syphilis in the future. The global STI vaccine roadmap outlines key activities to further advance STI vaccine development.

SUMMARY

Major progress is being made in addressing the large global unmet need for STI vaccines. With continued collaboration and support, these critically important vaccines for global sexual and reproductive health can become a reality.

Evaluating a college student's urethritis

Gonorrhea is the second most common sexually transmitted infection (STI) after chlamydia. After a significant decrease from 1975 to 2009, trends reveal that gonorrhea is on the rise. NPs need to review the latest CDC guidelines regarding STIs, as treatment guidelines are regularly changing.

Sexual behaviour of backpackers who visit Koh Tao and Koh Phangan, Thailand: a cross-sectional study

OBJECTIVES

To measure the proportion of backpackers engaging in unprotected sex while travelling in Thailand and to identify predictors of unsafe sexual behaviour.

METHODS

A cross-sectional study using an anonymous questionnaire was performed. English-speaking backpackers, excluding US and Thai citizens, were recruited while travelling through the piers of Koh Tao and Koh Phangan between 25 January and 13 March 2013.

RESULTS

61.5% (1238/2013) respondents were travelling without a long-term sexual partner, of whom 39.1% (29.4% females; 51.9% males) reported intercourse with a new partner. 36.8% of these reported inconsistent/no condom use. Inconsistent condom use was independently associated with age <25 years, UK (vs Canadian) nationality and not bringing condoms from home. Backpackers who brought condoms from home were more likely to have sex with a new partner. Male gender and longer trip length increased the likelihood of new partner acquisition and overall risk of unsafe sex but were not associated with inconsistent condom use. New partners were most commonly backpackers from other countries. Men were more likely than women to have sex with a local person.

CONCLUSIONS

Backpackers visiting Thailand frequently report unsafe sex. Partner demographics demonstrate a mechanism of international sexually transmitted infection (STI) transfer. In an era of growing antibiotic resistance and continuing HIV transmission, targeting unsafe sex in backpackers has the potential to reduce STI incidence internationally. These data highlight the need for innovative public health intervention. To focus such measures, future research may elucidate why certain groups are at higher risk.

The global roadmap for advancing development of vaccines against sexually transmitted infections: Update and next steps

In 2014, the World Health Organization, the US National Institutes of Health, and global technical partners published a comprehensive roadmap for development of new vaccines against sexually transmitted infections (STIs). Since its publication, progress has been made in several roadmap activities: obtaining better epidemiologic data to establish the public health rationale for STI vaccines, modeling the theoretical impact of future vaccines, advancing basic science research, defining preferred product characteristics for first-generation vaccines, and encouraging investment in STI vaccine development. This article reviews these overarching roadmap activities, provides updates on research and development of individual vaccines against herpes simplex virus, Chlamydia trachomatis, Neisseria gonorrhoeae, and Treponema pallidum, and discusses important next steps to advance the global roadmap for STI vaccine development.

Sexually Transmitted Infections

Sexually transmitted infections (STIs) remain a significant burden on public health in the United States. Primary prevention counseling with early diagnosis and treatment remain the best methods to decrease the incidence of STIs. Through significant public heath interventions, the incidence of gonorrhea, Chlamydia, and trichomoniasis is decreasing; however, the incidence of primary and secondary syphilis is increasing. Human papilloma virus remains the most common STI, but new vaccinations have the possibility of having a significant impact on this virus's disease potential. This review discusses the most common STIs in the United States, focusing on clinical presentation, diagnosis, and treatment.

Neisseria gonorrhoeae and fosfomycin: Past, present and future

Drug-resistant Neisseria gonorrhoeae has become a global health concern that requires immediate attention. Due to increasing resistance to cephalosporins, pursuing novel alternatives for treating N. gonorrhoeae infections is paramount. Whilst new drug development is often cumbersome, reviving antiquated antibiotic agents for treatment of modern infections has become prevalent in clinical practice. Fosfomycin exhibits bactericidal activity through a unique mechanism of action, and a variety of organisms including N. gonorrhoeae are susceptible. In vitro studies have demonstrated that fosfomycin can retain activity against ceftriaxone-resistant N. gonorrhoeae; however, it remains unclear whether there is synergy between fosfomycin and other antibiotics. Clinical investigations evaluating fosfomycin for the treatment of N. gonorrhoeae infections are confounded by methodological limitations, none the less they do provide some perspective on its potential role in therapy. Future studies are needed to establish a safe, convenient and effective fosfomycin regimen for treating N. gonorrhoeae infections.

[Antibiotic resistance: A global crisis]

The introduction of antibiotics into clinical practice represented one of the most important interventions for the control of infectious diseases. Antibiotics have saved millions of lives and have also brought a revolution in medicine. However, an increasing threat has deteriorated the effectiveness of these drugs, that of bacterial resistance to antibiotics, which is defined here as the ability of bacteria to survive in antibiotic concentrations that inhibit/kill others of the same species. In this review some recent and important examples of resistance in pathogens of concern for mankind are mentioned. It is explained, according to present knowledge, the process that led to the current situation in a short time, evolutionarily speaking. It begins with the resistance genes, continues with clones and genetic elements involved in the maintenance and dissemination, and ends with other factors that contribute to its spread. Possible responses to the problem are also reviewed, with special reference to the development of new antibiotics.

Stemming the tide of drug-resistant Neisseria gonorrhoeae: the need for an individualized approach to treatment

Drug-resistant Neisseria gonorrhoeae poses a significant public health challenge. In recent years, gonococci resistant to first- and second-line antibiotics have spread worldwide and new strains have developed that are increasingly resistant to third-generation cephalosporins, which are currently our last line of available treatments. Given the timeline required to develop new drugs or an effective vaccine for N. gonorrhoeae, a top priority is to use the drugs that are available as effectively as possible. Currently, clinical management of gonorrhoea is based upon treatment guidelines informed by international gonococcal antimicrobial susceptibility surveillance programmes. This approach, although currently the most practical, is subject to a number of limitations since surveillance data inherently provide population-level information. As a result, basing treatment guidelines on these data can result in the prescription of more aggressive or broader treatment than is needed by individual patients and hence inadvertently contribute to the development and spread of resistance to important drugs. Clearly, methods are needed that provide patient-specific drug susceptibility information in a time frame that would allow clinicians to prescribe individualized treatment regimens for gonorrhoea. Fortunately, in recent years, there have been a number of advances in the development of rapid methods for characterizing both the genotype and the drug resistance phenotype of N. gonorrhoeae strains. Here, we review these advances and propose additional studies that would help facilitate a transition towards an individualized treatment approach for gonorrhoea.

Toward global prevention of sexually transmitted infections (STIs): the need for STI vaccines

An estimated 499 million curable sexually transmitted infections (STIs; gonorrhea, chlamydia, syphilis, and trichomoniasis) occurred globally in 2008. In addition, well over 500 million people are estimated to have a viral STI such as herpes simplex virus type 2 (HSV-2) or human papillomavirus (HPV) at any point in time. STIs result in a large global burden of sexual, reproductive, and maternal-child health consequences, including genital symptoms, pregnancy complications, cancer, infertility, and enhanced HIV transmission, as well as important psychosocial consequences and financial costs. STI control strategies based primarily on behavioral primary prevention and STI case management have had clear successes, but gains have not been universal. Current STI control is hampered or threatened by several behavioral, biological, and implementation challenges, including a large proportion of asymptomatic infections, lack of feasible diagnostic tests globally, antimicrobial resistance, repeat infections, and barriers to intervention access, availability, and scale-up. Vaccines against HPV and hepatitis B virus offer a new paradigm for STI control. Challenges to existing STI prevention efforts provide important reasons for working toward additional STI vaccines. We summarize the global epidemiology of STIs and STI-associated complications, examine challenges to existing STI prevention efforts, and discuss the need for new STI vaccines for future prevention efforts.

Performance and comparison of self-reported STI symptoms among high-risk populations - MSM, sex workers, persons living with HIV/AIDS - in El Salvador

Resource-limited countries have limited laboratory capability and rely on syndromic management to diagnose sexually transmitted infections (STIs). We aimed to estimate the sensitivity, specificity and positive predictive value (PPV) of STI syndromic management when used as a screening method within a study setting. Men who have sex with men (MSM), female sex workers (FSWs) and people living with HIV/AIDS (PLWHA) participated in a behavioural surveillance study. Data were obtained on demographics, sexual behaviours, STI history and service utilisation. Biological specimens were tested for genital inflammatory infections (Neisseria gonorrhoeae [GC], Chlamydia trachomatis [CT], Mycoplasma genitalium [MG], Trichomonas vaginalis [TV]) and genital ulcerative infection (syphilis and Herpes simplex virus-2). There was a high prevalence of Herpes simplex virus-2 (MSM 48.1%, FSW 82.0% and PLWHA 84.4%). Most participants reported no ulcerative symptoms and the majority of men reported no inflammatory symptoms. Sensitivity and PPV were poor for inflammatory infections among PLWHA and MSM. Sensitivity in FSWs for inflammatory infections was 75%. For ulcerative infections, sensitivity was poor, but specificity and PPV were high. Reliance on self-reported symptoms may not be an effective screening strategy for these populations. STI prevention studies should focus on symptom recognition and consider routine screening and referral for high-risk populations.