Prophylaxis with single-dose doxycycline for the prevention of Lyme disease after an Ixodes scapularis tick bite

2024 American Heart Association and American Red Cross Guidelines for First Aid

Codeveloped by the American Heart Association and the American Red Cross, these guidelines represent the first comprehensive update of first aid treatment recommendations since 2010. Incorporating the results of structured evidence reviews from the International Liaison Committee on Resuscitation, these guidelines cover first aid treatment for critical and common medical, traumatic, environmental, and toxicological conditions. This update emphasizes the continuous evolution of evidence evaluation and the necessity of adapting educational strategies to local needs and diverse community demographics. Existing guidelines remain relevant unless specifically updated in this publication. Key topics that are new, are substantially revised, or have significant new literature include opioid overdose, bleeding control, open chest wounds, spinal motion restriction, hypothermia, frostbite, presyncope, anaphylaxis, snakebite, oxygen administration, and the use of pulse oximetry in first aid, with the inclusion of pediatric-specific guidance as warranted.

Epidemiology and clinical features of patients with tick bites in the Japanese spotted fever-endemic zone

PURPOSE

This study aimed to clarify the epidemiology and clinical features of tick bites in a Japanese spotted fever (JSF)-endemic area.

METHOD

The clinical records of patients with tick bites were retrospectively reviewed based on a survey conducted at Numakuma Hospital, Fukuyama City, Hiroshima, Japan, from 2016 to 2023. Data on basic characteristics, visit dates, residential address, exposure activities, tick-bite sites, and prophylactic antimicrobial prescriptions for each patient with tick bites were collected at the JSF hotspot hospital.

RESULTS

A total of 443 patients with tick bites visited the hospital, of which data on 305 cases (68.8 %) were reviewed. The median age of these patients was 71 years, with a higher proportion of women (63.0 %). One-third of the patients had a preceding history of working in fields, whereas two-thirds had entered mountains or agricultural fields. Nearly 90 % of the patients visited the hospital from April to August, and the most common bite sites were the lower extremities (45.1 %). Most patients (76.1 %) resided in the southern area of Numakuma Hospital. Nearly all patients were prescribed prophylactic antibiotics (minocycline in 87.8 % of cases), and none subsequently developed JSF.

CONCLUSION

Continued surveillance of patients with tick bites is warranted to better understand changes in the clinical impact of tick-borne diseases.

Review of doxycycline for prophylaxis of sexually transmitted infections

The surging rates of STIs necessitate medical practitioners in the appropriate specialties to focus on rapid recognition, treatment and prevention of these conditions. Through both pre- and post-exposure prophylaxis with doxycycline, dermatologists can provide up-to-date treatment in the field of venereology. Herein, we review the results of clinical trials in the available literature that investigate doxycycline prophylaxis in the prevention of bacterial STIs. A search was performed using the PubMED and Scopus databases which yielded six clinical trials for our review. Based on the results of these clinical trials, doxycycline prophylaxis offers significant reductions in bacterial STIs, specifically in men who have sex with men (MSM). Additional research is needed in other high-risk groups, including females. Moreover, additional research is needed to determine the effects of doxycycline prophylaxis on tetracycline resistance in STI-causing bacteria. As the utilization of doxycycline prophylaxis for STIs becomes more common, it is important that dermatologists become familiar with the data surrounding this prevention regimen and patient populations who may seek to know more about it. More research is needed to determine benefits in other subpopulations, antimicrobial resistance and cost effectiveness.

Frequency of tick bites and associated care-seeking behaviors in the United States

Tick-borne diseases are commonly reported in the United States, but frequency of tick bites and care-seeking behaviors following tick bites are poorly understood. We used nationally representative survey data to describe the frequency of tick bites among people living in the United States and how often, where, and why care-seeking associated with tick bites occurs. We found that over 31 million people (nearly 1 in 10) living in the United States might experience a tick bite each year and highlight regional trends in associated care-seeking behaviors. These findings emphasize the need for effective tick bite prevention education and regionally tailored healthcare provider recommendations for management of tick-borne diseases.

Hitchhiker's Guide to Borrelia burgdorferi

Don't Panic. In the nearly 50 years since the discovery of Lyme disease, Borrelia burgdorferi has emerged as an unlikely workhorse of microbiology. Interest in studying host-pathogen interactions fueled significant progress in making the fastidious microbe approachable in laboratory settings, including the development of culture methods, animal models, and genetic tools. By developing these systems, insight has been gained into how the microbe is able to survive its enzootic cycle and cause human disease. Here, we discuss the discovery of B. burgdorferi and its development as a model organism before diving into the critical lessons we have learned about B. burgdorferi biology at pivotal stages of its lifecycle: gene expression changes during the tick blood meal, colonization of a new vertebrate host, and developing a long-lasting infection in that vertebrate until a new tick feeds. Our goal is to highlight the advancements that have facilitated B. burgdorferi research and identify gaps in our current understanding of the microbe.

Current and emerging approaches for eliminating Borrelia burgdorferi and alleviating persistent Lyme disease symptoms

Lyme disease is the most prevalent tick-borne infection caused by Borrelia burgdorferi bacteria in North America. Other Borrelia species are predominately the cause of this disease in Eurasia with some distinct and various overlapping manifestations. Consequently, caution must be exercised when comparing the disease and its manifestations and treatment regimens in North America and Europe. Diagnosis of the early Lyme disease remains difficult using the currently FDA approved serological tests in the absence of a reported tick bite or of erythema migrans in many individuals, non-specific initial symptoms, and the absence of detectable anti-Borrelia antibodies in the prepatent period of infection. Furthermore, it is difficult to distinguish persistence of infection and disease versus reinfection in the endemic regions of Lyme disease by serological assays. If early infection remains untreated, spirochetes can disseminate and could affect various organs in the body with a variety of disease manifestations including arthralgias and musculoskeletal pain, neurologic symptoms and anomalies, and acrodermatitis chronicum atrophicans (ACA) in Europe. Although most patients recover after antibiotic treatment, an estimated ∼10-20% patients in the United States show persistence of symptoms known as post-treatment Lyme disease syndrome (PTLDS). The causes and biomarkers of PTLDS are not well-defined; however, several contributing factors with inconsistent degree of supporting evidence have been suggested. These include antigenic debris, dysregulation of immunological response, bacterial persisters, or combination of these features. This review highlights currently employed treatment approaches describing different antimicrobials used, and vaccine candidates tried to prevent B. burgdorferi infection.

How Do I Approach the Evaluation and Treatment of Early Lyme Disease?

AbstractThe incidence and geographic spread of Lyme disease are increasing, and more than 476,000 new cases a year are estimated to occur in the United States. Therefore, many clinicians in North America will need to consider how to approach a patient with a concern for Lyme disease. This Curbside Consult addresses common clinical considerations, including discussion of signs of early Lyme disease, available laboratory tests, when to treat and with which antibiotics.

Frequency of Lyme disease in patients with tick contact and identification of ticks from Bolu province of Turkey

BACKGROUND OBJECTIVES

Lyme disease is a multisystemic disease caused by the bacteria in the Borrelia burgdorferi sensu lato complex, which is transmitted by ticks of the Ixodes genus. Although there are seroprevalence studies and case reports of Lyme disease from various regions in Turkey, there is no widespread epidemiological research. This study aimed to determine the frequency of Lyme disease in the cases followed-up after tick contact and to examine the isolated ticks to reveal tick population from Bolu province.

METHODS

In this study, cases who applied to the emergency department due to tick contact between April and September 2020 were firstly evaluated in our infectious diseases and clinical microbiology outpatient clinic on the third day of exposure and antibodies against Lyme disease were investigated with the IFA method to exclude the patients who were previously exposed to B. burgdorferi. Thereafter, patients were requested to continue outpatient visits at the 1 st and 3 rd month control. At these controls, serum samples were taken to study B.burgdorferi antibodies with the ELISA method which were stored at - 20°C until the study day.

RESULTS

Out of 123 patients who came to first control, 69 patients continued later to at least one of the two controls (either at first or third month). Of these 69 patients, only one (1.4%) was diagnosed with Lyme borreliosis according to clinical and laboratory features. Erythema migrans did not occur in any of the cases. Serum samples were assessed by ELISA method. Asymptomatic infection was detected in 22 cases (30.5%). In addition, we could obtain 46 ticks from our cases and two genera were identified. Forty-two (91.3%) were Ixodes spp. , and two (4.3%) were Hyalomma spp.

INTERPRETATION CONCLUSION

In this study, which was carried out for the first time in the province of Bolu, it was concluded that the cases presenting with a history of tick contact were most frequently exposed to Ixodes spp ticks, and the probability of developing Lyme borreliosis was low (1,4%) during the three-month follow-up period. Further studies with more number of cases and more extended follow-up period are needed.

Spatiotemporal patterns of Lyme disease in North Carolina: 2010-2020

Background

Lyme disease is the most common vector-borne disease in the United States with the majority of cases occurring in the Northeast, upper Midwest, and mid-Atlantic regions. While historically considered a low incidence state, North Carolina (NC) has reported an increasing number of cases over the past decade. Therefore, the aim of this study was to characterise the spatiotemporal evolution of Lyme disease in NC from 2010 to 2020.

Methods

Confirmed and probable cases reported to the NC Division of Public Health without associated travel to high-transmission state were included in the analysis. The study period was divided into four sub-periods and data were aggregated by zip code of residence. The absolute change in incidence was mapped and spatial autocorrelation analyses were performed within each sub-period.

Findings

We identified the largest absolute changes in incidence in zip codes located in northwestern NC along the Appalachian Mountains. The spatial distribution of cases became increasingly clustered over the study period (Moran's I of 0.012, p = 0.127 in 2010-2012 vs. 0.403, p < 0.0001 in 2019-2020). Identified clusters included 22 high-incidence zip codes in the 2019-2020 sub-period, largely overlapping with the same areas experiencing the greatest absolute changes in disease incidence.

Interpretation

Lyme disease has rapidly emerged in northwestern NC with some zip codes reporting incidence rates similar to historically high incidence regions across the US Northeast, mid-Atlantic, and upper Midwest. Efforts are urgently needed to raise awareness among medical providers to prevent excess morbidity.

Funding

Funding was provided by a "Creativity Hub" award from the UNC Office of the Vice Chancellor for Research. Additional support was provided by Southeastern Center of Excellence in Vector Borne Diseases (U01CK000662).

CDC Clinical Guidelines on the Use of Doxycycline Postexposure Prophylaxis for Bacterial Sexually Transmitted Infection Prevention, United States, 2024

No vaccines and few chemoprophylaxis options exist for the prevention of bacterial sexually transmitted infections (STIs) (specifically syphilis, chlamydia, and gonorrhea). These infections have increased in the United States and disproportionately affect gay, bisexual, and other men who have sex with men (MSM) and transgender women (TGW). In three large randomized controlled trials, 200 mg of doxycycline taken within 72 hours after sex has been shown to reduce syphilis and chlamydia infections by >70% and gonococcal infections by approximately 50%. This report outlines CDC's recommendation for the use of doxycycline postexposure prophylaxis (doxy PEP), a novel, ongoing, patient-managed biomedical STI prevention strategy for a selected population. CDC recommends that MSM and TGW who have had a bacterial STI (specifically syphilis, chlamydia, or gonorrhea) diagnosed in the past 12 months should receive counseling that doxy PEP can be used as postexposure prophylaxis to prevent these infections. Following shared decision-making with their provider, CDC recommends that providers offer persons in this group a prescription for doxy PEP to be self-administered within 72 hours after having oral, vaginal, or anal sex. The recommended dose of doxy PEP is 200 mg and should not exceed a maximum dose of 200 mg every 24 hours.Doxy PEP, when offered, should be implemented in the context of a comprehensive sexual health approach, including risk reduction counseling, STI screening and treatment, recommended vaccination and linkage to HIV PrEP, HIV care, or other services as appropriate. Persons who are prescribed doxy PEP should undergo bacterial STI testing at anatomic sites of exposure at baseline and every 3-6 months thereafter. Ongoing need for doxy PEP should be assessed every 3-6 months as well. HIV screening should be performed for HIV-negative MSM and TGW according to current recommendations.

Lyme Borreliosis, a public health concern in India: Findings of Borrelia burgdorferi serosurvey from two states

Background

Lyme borreliosis is a public health concern in India. The prevalence of the disease is still undetermined with major entomological and epidemiological gaps. The present study was conducted to determine the seropositivity of Borrelia burgdorferi in Sikkim and Arunachal Pradesh, India.

Methods

A cross-sectional serosurvey was conducted in Sikkim and Arunachal Pradesh. Data collection tools were developed and standardized for the collection of clinico-socio-demographic data. Sample size for each site was calculated using the formula for the estimation of a single proportion. Qualitative detection of IgG antibodies in serum samples was done using NovaLisa™ Lyme Borrelia IgG ELISA kit.

Results

A total of 793 participants were enrolled, 484 (61%) from Arunachal Pradesh and 309 (39%) from Sikkim. Out of 793 participants, 21 (2.7%), 22 (2.8%), 6 (0.8%), 29 (3.7%), 44 (5.5%), and 16 (2.1%) gave history of tick bite, rash, erythema migrans, migratory muscle pain, migratory joint pain, and numbness, respectively, in the past one year. The adjusted seroprevalence (for sensitivity and specificity of kit) for the study is 3.7 (2.4-5.2). No signs or symptoms were found to be associated with IgG ELISA positivity. The state-wise distribution of seropositivity for Arunachal Pradesh and Sikkim was 4.1 (95% CI: 2.5-6.3) and 2.3 (95% CI: 0.9-4.6), respectively.

Conclusion

This study establishes the state of Sikkim as a new endemic area in India of Lyme disease besides its already reported endemicity in Arunachal Pradesh. No association was conclusively established between symptoms of Lyme and IgG seropositivity emphasizing the need for detailed history taking and clinical suspicion in endemic areas.

Delayed Diagnosis of Locally Acquired Lyme Disease, Central North Carolina, USA

Healthcare providers in North Carolina, USA, have limited experience diagnosing and managing Lyme disease because few cases occur annually statewide. We outline the prolonged diagnostic course for a patient with locally acquired Lyme disease in North Carolina. This case highlights the need for greater awareness and professional education.

Pharmacokinetics of single dose doxycycline in the rectum, vagina, and urethra: implications for prevention of bacterial sexually transmitted infections

BACKGROUND

Clinical trials showed a single oral dose of doxycycline taken after sex protects against STIs among men who have sex with men (MSM) but not women. Pharmacokinetic data at vaginal, rectal and penile sites of STI exposure are lacking. We examined vaginal, rectal and urethral doxycycline concentrations in men and women to better inform STI prevention.

METHODS

Doxycycline pharmacokinetics in male and female participants 18-59 years of age were evaluated in blood and urine and on rectal and vaginal swabs collected at 1, 2, 4, 8, 24, 48, 72, 96 and 168 h after receiving a 200 mg oral doxycycline dose in a non-randomised single dose open label single centre study in Atlanta, Georgia. Rectal, vaginal, and cervical biopsies and male urethral swabs were collected 24 h after dosing (Trial registration: NCT04860505). Doxycycline was measured by liquid chromatography-mass spectrometry.

FINDINGS

Eleven male and nine female participants participated in the study. Doxycycline concentrations on rectal and vaginal swabs collected up to 96 h after dosing were approximately twice those of plasma and remained above minimum inhibitory concentrations (MICs) for at least four, three, and two days for Chlamydia trachomatis, Treponema pallidum, and tetracycline-sensitive Neisseria gonorrhoeae, respectively. Geometric mean doxycycline concentrations in male urethral secretions (1.166 μg/mL; 95% CI 0.568-2.394 μg/mL), male rectal (0.596 μg/g; 0.442-0.803 μg/g), vaginal (0.261 μg/g; 0.098-0.696 μg/g) and cervical tissue (0.410 μg/g; 0.193-0.870 μg/g) in biopsies collected 24 h after dosing exceeded MICs. Plasma and urine doxycycline levels defined adherence markers up to four and seven days postdosing, respectively. No adverse events were reported in this study.

INTERPRETATION

Doxycycline efficiently distributes to the rectum, vagina and urethra. Findings can help explain efficacy of STI prevention by doxycycline.

FUNDING

Funded by CDC intramural funds, CDC contract HCVJCG-2020-45044 (to CFK).

The major epidemiologic, microbiologic, immunologic, and clinical aspects of Lyme disease that form the basis for a newly developed vaccine that may become available soon for human use

Working together, two major pharmaceutical companies have developed a Lyme disease vaccine consisting of recombinant-derived outer surface protein A (OspA) of the etiologic agent Borrelia burgdorferi. Multiple clinical trials have shown the vaccine to have good safety and efficacy results, and it is hoped that it would become available for human use at least by the year 2025 after receiving approval from the U.S. Food and Drug Administration. There are still challenges left to ensure that the vaccine has, at most, minimal side effects. Also, because the previously developed Lyme disease vaccine was discontinued in 2002 after four years of distribution, due in part, for frivolous reasons having little or no scientific basis, that even led to legal entanglements involving the vaccine manufacturer and some of the medical personnel overseeing the clinical trials, there will be concerns that this newly developed one could be subject again to some of the same unnecessary scrutiny rendering its implementation suboptimal. Initially this review will focus on the key epidemiological, microbiologic, immunologic and clinical aspects of Lyme disease that provide the foundation for developing this type of vaccine that could have a serious impact on the prevalence of this and even certain other tick-transmitted infections.

Atypical Lyme Disease Rash: A Case Report

Lyme disease (LD), caused in the United States primarily by Borrelia burgdorferi sensu lato, is a tick-borne illness characterized by a spectrum of clinical manifestations depending on the stage of illness. Most clinicians are familiar with the classic bullseye appearance of the erythema migrans (EM) rash that occurs in the early stage of the disease. However, many providers may not be aware of alternate appearances for the rash. This paper reports the case of a 69-year-old female with LD, exhibiting an atypical rash with purplish discoloration that was devoid of an outer ring or central clearing. In geographic areas with a high incidence of LD, it is especially important for clinicians to recognize alternative LD presentations. Healthcare providers should maintain a high index of suspicion of LD in patients with tick bites, even without typical EM, to ensure early diagnosis and treatment. Education on diverse LD presentations is crucial for improving public health outcomes.

Safety of Longer-Term Doxycycline Use: A Systematic Review and Meta-Analysis With Implications for Bacterial Sexually Transmitted Infection Chemoprophylaxis

BACKGROUND

Sexually transmitted infections (STIs) such as syphilis, gonorrhea, and chlamydia have significantly increased over the past decade in the United States. Doxycycline as chemoprophylaxis (i.e., postexposure prophylaxis) offers promise for addressing bacterial STIs. The goal of the current study was to evaluate the safety of longer-term doxycycline use (defined as 8 or more weeks) in the context of potential use as STI chemoprophylaxis through a systematic literature review and meta-analysis.

METHODS

This review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to search MEDLINE/PubMed for clinical studies published from August 2003 to January 2023 that reported on adverse events with doxycycline use with a focus on side effects and metabolic effects of long-term use.

RESULTS

A total of 67 studies were included in the systematic review. Overall, studies on longer-term doxycycline use reported 0% to greater than 50% adverse events ranging from mild to severe. Most common adverse events included gastrointestinal symptoms (i.e., nausea, vomiting, and abdominal pain), dermatologic (i.e., rash), and neurological (i.e., headache and dizziness) symptoms. Discontinuation of doxycycline due to adverse events was relatively uncommon in most studies. A meta-analysis of placebo controlled clinical trials (N = 18) revealed that gastrointestinal and dermatological adverse events were more likely to occur in the doxycycline group.

CONCLUSIONS

Longer-term (8+ weeks) doxycycline use is generally safe and may be associated with minor side effects. Further research is needed on the potential metabolic impact of longer-term doxycycline use.

A patient with secondary syphilis following incomplete treatment of primary infection

Syphilis is a bacterial infection caused by Treponema pallidum and is primarily transmitted via skin-to-skin or mucosal contact during sexual encounters, or through vertical transmission during pregnancy. Cases continue to rise globally across various demographic groups despite effective treatment and prevention interventions. We discuss the case of a 28-year-old cisgender man who presented with secondary syphilis 1 month after being inadequately treated for primary syphilis. Individuals can present with symptoms and signs of syphilis to clinicians of various subspecialties due to diverse clinical presentation. All health-care providers should be able to identify the common and less common manifestations of this infection, and adequate treatment and follow-up are crucial to preventing serious sequelae. Novel biomedical prevention interventions, such as doxycycline post-exposure prophylaxis, are on the horizon.

Infectious Neuropathies

OBJECTIVE

This article discusses the clinical manifestations and management of infectious peripheral neuropathies.

LATEST DEVELOPMENTS

Several infectious etiologies of peripheral neuropathy are well-recognized and their treatments are firmly established. The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with several central and peripheral nervous system manifestations, including peripheral neuropathies. Additionally, some COVID-19 vaccines have been associated with Guillain-Barré syndrome. These disorders are an active area of surveillance and research. Recent evidence-based guidelines have provided updated recommendations for the diagnosis and treatment of Lyme disease.

ESSENTIAL POINTS

Infectious agents of many types (primarily bacteria and viruses) can affect the peripheral nerves, resulting in various clinical syndromes such as mononeuropathy or mononeuropathy multiplex, distal symmetric polyneuropathy, radiculopathy, inflammatory demyelinating polyradiculoneuropathy, and motor neuronopathy. Knowledge of these infections and the spectrum of peripheral nervous system disorders associated with them is essential because many have curative treatments. Furthermore, understanding the neuropathic presentations of these disorders may assist in diagnosing the underlying infection.

Illnesses and Injuries at a Remote American Residential Summer Camp Over 3 Seasons

INTRODUCTION

Residential and wilderness excursion summer camps are safe, but outdoor activities can lead to injuries. The frequency of various illnesses and injuries at summer camps has been incompletely described. The treatments provided and the need for escalation to higher levels of care are variable.

METHODS

A retrospective cohort analysis was conducted for all visits to a camp infirmary over 3 seasons at a residential summer camp in Minnesota. Seventeen descriptive categories of chief complaints and 13 categories of treatment disposition were created for all 695 eligible infirmary visits. The frequency and illness type for which escalation to a higher level of care beyond the camp infirmary was needed were reviewed.

RESULTS

Four hundred one campers sought medical care 695 times over 3 seasons. The most common chief complaints were related to skin (35%), musculoskeletal injury (17%), and upper-respiratory symptoms (15%). The most common treatment and dispositions were over-the-counter medications (43%) and simple bandage or dressing (19%). Escalation of care to a clinic or emergency room was uncommon, with 35 (5%) infirmary visits requiring escalation. Musculoskeletal injuries were the most common reason for escalations of care. While overall less common than musculoskeletal injury, dental injury almost always resulted in escalation of care.

CONCLUSIONS

An analysis of 3 y of visits to a summer camp infirmary was used by camp medical staff to update protocols and obtain new supplies for diagnosis and treatments. A more complete understanding of the prevalence of injuries and illnesses has the potential to allow better preparation for camp medical staff.

Seroprevalence and risk factors of Borrelia burgdorferi sensu lato and Rickettsia species infection in humans in Mongolia, 2016-2020

Borrelia burgdorferi sensu lato and Rickettsia spp. are worldwide causes of tick-borne infections. We aimed to estimate the seroprevalence of immunoglobulin G (IgG) antibodies against different tick-borne diseases (TBDs) and determine risk factors among Mongolians from 2016 to 2020. Blood samples were obtained from voluntary participants with a history of suspected tick bite who visited our hospital, and IgG antibodies against Rickettsia and Borrelia were detected using enzyme-linked immunosorbent assay (ELISA). The IgG antibody seropositivity rate against Rickettsia was 21.8% (1032/4724), while 3.4% (162/4724) of participants tested positive for serum IgG antibodies against Borrelia by ELISA.Binary logistic regression analysis was performed to evaluate risk factors for tick-borne rickettsiosis (TBR) and tick-borne borreliosis (TBB) using IgG serum sample. Age, occupation, and residence were significantly associated with these diseases; however, sex did not show any significant association. Seroprevalence was significantly higher among herders (40.6%, 95% confidence interval [CI]: 35.5-45.8; odds ratio [OR] 0.61; P < 0.001) and students (32.8%, 95% CI: 30.2-35.4; OR 0.75; P < 0.001) than among individuals with other occupations. The 25-29 age group had a slightly higher seroprevalence (35.1%, 95% CI: 28.1-42.6; OR 0.61; P < 0.006) than those in other age groups. Province was a stronger predictor of TBR than occupation and age group. In univariate subgroup analysis by age group, occupation, and residence were significantly associated with TBR seroprevalence, whereas age and province were associated with TBB seroprevalence. Thus, risk factors for TBD include residence, occupation, and age group. This study was conducted using samples from all Mongolian provinces and the capital city, and the risk factors and prevalence of Rickettsia and Borreliaare highlighted.

Lactate Dehydrogenase Inhibitors Suppress Borrelia burgdorferi Growth In Vitro

Borrelia burgdorferi, the causative agent of Lyme disease, has a highly reduced genome and relies heavily on glycolysis for carbon metabolism. As such, established inhibitors of lactate dehydrogenase (LDH) were evaluated in cultures to determine the extent of their impacts on B. burgdorferi growth. Both racemic and enantiopure (AT-101) gossypol, as well as oxamate, galloflavin, and stiripentol, caused the dose-dependent suppression of B. burgdorferi growth in vitro. Racemic gossypol and AT-101 were shown to fully inhibit spirochetal growth at concentrations of 70.5 and 187.5 μM, respectively. Differences between racemic gossypol and AT-101 efficacy may indicate that the dextrorotatory enantiomer of gossypol is a more effective inhibitor of B. burgdorferi growth than the levorotatory enantiomer. As a whole, LDH inhibition appears to be a promising mechanism for suppressing Borrelia growth, particularly with bulky LDH inhibitors like gossypol.

Passive Surveillance of Human-Biting Ixodes scapularis Ticks in Massachusetts from 2015-2019

This study aimed to analyze human-biting Ixodes scapularis ticks submitted to TickReport tick testing service from 2015-2019 in Massachusetts to (1) examine possible patterns of pathogen-positive adult and nymphal ticks over time and (2) explore how socioeconomic factors can influence tick submissions. A passive surveillance data set of ticks and tick-borne pathogens was conducted over 5 years (2015-2019) in Massachusetts. The percentages of four tick-borne pathogens: Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti, and Borrelia miyamotoi were determined by Massachusetts county and by month and year. Regression models were used to examine the association between zip-code-level socioeconomic factors and submissions. A total of 13,598 I. scapularis ticks were submitted to TickReport from Massachusetts residents. The infection rate of B. burgdorferi, A. phagocytophilum, and B. microti was 39%, 8%, and 7% in adult ticks; 23%, 6%, and 5% in nymphal ticks, respectively. A relatively higher level of education was associated with high tick submission. Passive surveillance of human-biting ticks and associated pathogens is important for monitoring tick-borne diseases, detecting areas with potentially high risks, and providing public information. Socioeconomic factors should be considered to produce more generalizable passive surveillance data and to target potentially underserved areas.

Tick species infesting humans in the United States

The data for human tick encounters in the United States (US) presented in this paper were compiled with the goals of: (i) presenting quantitative data across the full range of native or recently established human biting ixodid (hard) and argasid (soft) tick species with regards to their frequency of infesting humans, based on published records of ticks collected while biting humans or crawling on clothing or skin; and (ii) providing a guide to publications on human tick encounters. Summary data are presented in table format, and the detailed data these summaries were based on are included in a set of Supplementary Tables. To date, totals of 36 ixodid species (234,722 specimens) and 13 argasid species (230 specimens) have been recorded in the published literature to infest humans in the US. Nationally, the top five ixodid species recorded from humans were the blacklegged tick, Ixodes scapularis (n=158,008 specimens); the lone star tick, Amblyomma americanum (n=36,004); the American dog tick, Dermacentor variabilis (n=26,624); the western blacklegged tick, Ixodes pacificus (n=4,158); and the Rocky Mountain wood tick, Dermacentor andersoni (n=3,518). Additional species with more than 250 ticks recorded from humans included Ixodes cookei (n=2,494); the Pacific Coast tick, Dermacentor occidentalis (n=809); the brown dog tick, Rhipicephalus sanguineus sensu lato (n=714); the winter tick, Dermacentor albipictus (n=465); and the Gulf Coast tick, Amblyomma maculatum (n=335). The spinose ear tick, Otobius megnini (n=69), and the pajaroello tick, Ornithodoros coriaceus (n=55) were the argasid species most commonly recorded from humans. Additional information presented for each of the 49 tick species include a breakdown of life stages recorded from humans, broad geographical distribution in the US, host preference, and associated human pathogens or medical conditions. The paper also provides a history of publications on human tick encounters in the US, with tables outlining publications containing quantitative data on human tick encounters as well as other notable publications on human-tick interactions. Data limitations are discussed. Researchers and public health professionals in possession of unpublished human tick encounter data are strongly encouraged to publish this information in peer-reviewed scientific journals. In future papers, it would be beneficial if data consistently were broken down by tick species and life stage as well as host species and ticks found biting versus crawling on clothing or skin.

Epidemiology of Lyme Disease

Lyme disease is the most common vector-borne illness in North America and Europe. The etiologic agent, Borrelia burgdorferi sensu lato, is transmitted to humans by certain species of Ixodes ticks, which are found widely in temperate regions of the Northern hemisphere. Clinical features are diverse but death is rare. The risk of human infection is determined by the distribution and abundance of vector ticks, ecologic factors influencing tick infection rates, and human behaviors that promote tick bite. Rates of infection are highest among children aged 5 to 15 years and adults aged more than 50 years. In the northeastern United States where disease is most common, exposure occurs primarily in areas immediately around the home. Knowledge of disease epidemiology is important for patient management and proper diagnosis.

Doxycycline post-exposure prophylaxis for prevention of sexually transmitted infections among Kenyan women using HIV pre-exposure prophylaxis: study protocol for an open-label randomized trial

BACKGROUND

Women in Africa face disproportionate risk of human immunodeficiency virus (HIV) acquisition, accounting for more than half of new infections in Africa and similarly face a disproportionate burden of sexually transmitted infections (STIs). Very high STI prevalence is being observed globally, especially among people taking pre-exposure prophylaxis (PrEP) for HIV prevention. Doxycycline post-exposure prophylaxis (dPEP) has been proposed as an STI prevention strategy to reduce chlamydia, syphilis, and possibly gonorrhea, and trials are ongoing among cisgender men who have sex with men (MSM) and transgender women who are taking PrEP in high-income settings. We designed and describe here the first open-label trial to determine the effectiveness of dPEP to reduce STI incidence among cisgender women.

METHODS

We are conducting an open-label 1:1 randomized trial of dPEP versus standard of care (STI screening and treatment and risk-reduction counseling without dPEP) among 446 Kenyan women aged ≥ 18 and ≤ 30 years old women taking PrEP. Women are followed for 12 months, with quarterly STI testing, treatment, and adherence counseling. The primary trial outcome will be the combined incidence of Chlamydia trachomatis, Neisseria gonorrhoeae, and Treponema pallidum, compared between the randomized groups. We will also assess dPEP acceptability, tolerability, safety, impact on sexual behavior, adherence, and occurrence of antimicrobial resistance (AMR) in N. gonorrhoeae and C. trachomatis isolates. Finally, we will estimate cost per incident STI case and complications averted accounting for nonadherence and benefits relative AMR or side effects.

DISCUSSION

The results of this trial may have immediate implications for the global epidemic of STIs and sexual health. If effective, dPEP could put STI prevention into women's hands. While dPEP may be able to prevent STIs, it carries important risks that could counter its benefits; global debate about the balance of these potential risks and benefits requires data to inform policy and implementation and our study aims to fill this gap.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04050540 .

Antibiotic prophylaxis for prevention against Lyme disease following tick bite: an updated systematic review and meta-analysis

Background

In areas where Lyme disease is endemic, bites from ticks are common, but no vaccine is currently available against Lyme disease for humans. Therefore, the feasibility of using antibiotic prophylaxis to prevent Lyme disease after a tick bite is worth further exploration. Previous meta-analyses lack sufficient power to demonstrate the efficacy of about antibiotic prophylaxis for the prevention of Lyme disease following a tick bite. In this study, we explored more precise evidence and attempted to identify and update optimum treatment strategies.

Methods

We searched PubMed, Embase, and the Cochrane Library for studies until March 23, 2021. We included studies if the enrolled patients were randomly allocated to a treatment or control group within 72 h following a tick bite and had no clinical evidence of Lyme disease at enrolment. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were followed for data abstraction. Two authors (GZZ and XX) independently reviewed the abstracts and identified articles for detailed assessment. We used a random-effects model to calculate the pooled results and reported the 95% confidence interval (CI). Study quality was assessed using a modified Jadad scale, and publication bias was assessed using Egger’s test. We calculated the risk ratio (RR) for the rates of unfavorable events in patients who received intervention versus the control group. This study is registered with PROSPERO, number CRD42021245002.

Results

Six studies (3,766 individuals) were included. The pooled rate of unfavorable events in persons receiving treatment and the control group were 0.4% (95%CI: 0.1–1.1%) and 2.2% (95%CI: 1.6–3.0%), respectively. The pooled RR was 0.38 (95%CI: 0.22–0.66). Subgroup analysis revealed that the pooled RR was 0.29 (95%CI: 0.14–0.60) in the single-use 200-mg doxycycline group; 0.28 (95%CI: 0.05–1.67) in a 10-day course group (Amoxicillin, Penicillin or tetracycline); and 0.73 (95%CI: 0.25–2.08) in a topical antibiotic treatment group (Azithromycin).

Conclusions

The available evidence supports the use of antibiotics for the prevention of Lyme disease, and reveals advantages of using single-dose; however, further confirmation is needed.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Management of Tick-Borne Illness in the United States

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the prevention and management of tick-borne illness (TBI). Recommendations are graded based on quality of supporting evidence according to criteria put forth by the American College of Chest Physicians. The guidelines include a brief review of the clinical presentation, epidemiology, prevention, and management of TBI in the United States, with a primary focus on interventions that are appropriate for resource-limited settings. Strong recommendations are provided for the use of DEET, picaridin, and permethrin; tick checks; washing and drying clothing at high temperatures; mechanical tick removal within 36 h of attachment; single-dose doxycycline for high-risk Lyme disease exposures versus "watchful waiting;" evacuation from backcountry settings for symptomatic tick exposures; and TBI education programs. Weak recommendations are provided for the use of light-colored clothing; insect repellents other than DEET, picaridin, and permethrin; and showering after exposure to tick habitat. Weak recommendations are also provided against passive methods of tick removal, including the use of systemic and local treatments. There was insufficient evidence to support the use of long-sleeved clothing and the avoidance of tick habitat such as long grasses and leaf litter. Although there was sound evidence supporting Lyme disease vaccination, a grade was not offered as the vaccine is not currently available for use in the United States.

A brief history of OspA vaccines including their impact on diagnostic testing for Lyme disease

The only United States Food and Drug Administration approved vaccine preparation to prevent Lyme disease consisted of a single recombinant outer surface protein A (OspA), which was marketed for use from late 1998 until early 2002, with no vaccine currently available for humans for nearly 20 years. OspA vaccines generate an antibody-mediated, transmission blocking immunity, that prevents Borrelia burgdorferi from being transmitted during a tick bite. Although this OspA vaccine was safe and effective, it likely would have required booster doses to maintain immunity, and vaccination regularly caused false positive results on first-tier serologic testing for Lyme disease, when a whole cell-based enzyme immunoassay was used. Clinical trials are in progress to test a new multivalent OspA vaccine designed to prevent Lyme disease in both the United States and Europe.

A Traumatic Tick Bite: A Case Report

Introduction

Human granulocytic anaplasmosis is a tick-borne disease with an increasing incidence associated with morbidity and mortality. Uncertainty remains whether a prophylactic dose of doxycycline is effective in prevention.

Case Report

We present a case of an 80-year-old female with syncope, resultant facial trauma, and fever two weeks after a tick bite for which she received prophylaxis. Workup revealed anaplasmosis, and treatment led to symptomatic improvement.

Conclusion

We review the presenting symptoms, laboratory findings, and treatment of anaplasmosis, as well as give caution about the limitations in prescribing a prophylactic dose of doxycycline following a tick bite.

Emergency Department Visits for Tick Bites - United States, January 2017-December 2019

The incidence of tickborne diseases in the United States is increasing; reported cases more than doubled from >22,000 in 2004 to >48,000 in 2016 (1). Ticks are responsible for approximately 95% of all locally acquired vectorborne diseases reported by states and the District of Columbia, with Lyme disease accounting for >80% of those cases (2). After a tick bite, persons might seek care at an emergency department (ED) for tick removal and to receive postexposure prophylaxis, which has been shown to effectively prevent Lyme disease when taken within 72 hours of a high-risk bite (3). Using data from CDC's National Syndromic Surveillance Program (NSSP), investigators examined ED tick bite visits during January 2017-December 2019 by sex, age group, U.S. region, and seasonality. During this 36-month period, 149,364 ED tick bite visits were identified. Mean cumulative incidence was 49 ED tick bite visits per 100,000 ED visits overall; incidence was highest in the Northeast (110 per 100,000 ED visits). The seasonal distribution of ED tick bite visits was bimodal: the larger peak occurred during the spring and early summer, and the smaller peak occurred in the fall. This pattern aligns with the seasonality of a known and abundant human-biter, the blacklegged tick, Ixodes scapularis (4). Compared with other age groups, pediatric patients aged 0-9 years accounted for the highest number and incidence of ED tick bite visits; incidence was higher among male patients than among females. Tick bites are not monitored by current surveillance systems because a tick bite is an event that in and of itself is not a reportable condition to health departments. Syndromic surveillance of ED tick bite visits can provide timely information that might predict temporal and geographic risk for exposure to tickborne diseases and guide actionable public health messaging such as avoiding tick habitats, wearing repellent consistently when outdoors, and performing regular tick checks during times of increased tick bite risk.

Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA), American Academy of Neurology (AAN), and American College of Rheumatology (ACR): 2020 Guidelines for the Prevention, Diagnosis and Treatment of Lyme Disease

This evidence-based clinical practice guideline for the prevention, diagnosis, and treatment of Lyme disease was developed by a multidisciplinary panel representing the Infectious Diseases Society of America (IDSA), the American Academy of Neurology (AAN), and the American College of Rheumatology (ACR). The scope of this guideline includes prevention of Lyme disease, and the diagnosis and treatment of Lyme disease presenting as erythema migrans, Lyme disease complicated by neurologic, cardiac, and rheumatologic manifestations, Eurasian manifestations of Lyme disease, and Lyme disease complicated by coinfection with other tick-borne pathogens. This guideline does not include comprehensive recommendations for babesiosis and tick-borne rickettsial infections, which are published in separate guidelines. The target audience for this guideline includes primary care physicians and specialists caring for this condition such as infectious diseases specialists, emergency physicians, internists, pediatricians, family physicians, neurologists, rheumatologists, cardiologists and dermatologists in North America.

Single Dose of Doxycycline for the Prevention of Tick-borne Relapsing Fever

The current postexposure prophylaxis regimen for tick-borne relapsing fever (TBRF) consists of 5 days' doxycycline. In this observational study of 77 spelunkers at high risk for TBRF, a single dose of 100 mg doxycycline taken up to 72 hours after exposure to ticks was 100% effective in preventing the disease.

Doxycycline for Prevention of Spirochetal Infections: Status Report

Important human infections caused by spirochetal microorganisms include Lyme disease, syphilis, leptospirosis, and tick-borne relapsing fever. Doxycycline prophylactic regimens have been shown to significantly reduce the risk for developing all of these infections in potentially exposed individuals, which is highly clinically relevant as no vaccines to prevent these infections in humans are currently available. Additional data, however, are needed to define more precisely the level of efficacy of the doxycycline prophylactic regimens, especially for Lyme disease and syphilis, infections that can be potentially prevented by a single 200-mg dose of doxycycline given within 72 hours postexposure.

First Data on Human Lyme Borreliosis in Kosovo: Prospective Evaluation of the Disease from a Tick Bite Perspective

Purpose: Lyme borreliosis (LB) occurs throughout Europe. No clinical and seroprevalence studies for LB in Kosovo have been publicly available thus far. Therefore, this study aimed to investigate LB from a tick bite perspective in the Pristina region, Kosovo. Methods: This single-center prospective observational study enrolled consecutive adult participants (≥18 years of age) with tick bite (embedded tick in the skin), who were examined at the Clinic of Infectious Diseases, Pristina, between January 2015 and August 2018. At the first visit related to the index tick bite, ticks (the complete ticks or parts of the ticks) were removed from the skin, blood samples were taken for serological tests, and antibiotic treatment was started when deemed necessary. The complete, undamaged ticks removed were proceeded for entomological identification. Participants were followed up at 2 months (serological tests were repeated) and 6 months after the index event for the development of clinical manifestations of LB and/or seroconversion against Borrelia burgdorferi. Results: A total of 380 subjects were included in the study. Most cases were seen in May and June in all study years. All 117 preserved ticks were identified as Ixodes ricinus. Immunoglobulin G seroprevalence among subjects during the first visit in the study was 28/380 (7.4%). Erythema migrans (EM) was clinically diagnosed in 74/380 patients (19.5%, 95% confidence interval 15.6-23.8). Only 15 clinically diagnosed EM (in seronegative patients) were serologically confirmed with seroconversion (2 months later), 3.9% of all subjects included in the study. There were three cases with clinical manifestation between the second and third visit: EM recidivans, multiple erythema, or several nonspecific systemic symptoms. Doxycycline and amoxicillin were mainly used for the treatment of borrelial skin lesions. Conclusion: This assessment can help indicate the need for disease awareness and reinforce the importance of primary prevention measures, early diagnosis, and appropriate treatment.

Lyme disease: "End of the debate?"

Lyme borreliosis is a tick-borne disease that is widespread throughout the northern hemisphere. Ixodes ricinus is present throughout metropolitan France, except for the Mediterranean region. The debate revolves around whether or not a chronic form of Lyme disease exists. This controversy is not limited to France but has been reported worldwide. In France, in 2019, 24 scientific societies representing the medical disciplines most involved in Lyme disease, including the Société Française de Rhumatologie (French Rheumatology Society [SFR]) and the Société de Pathologie Infectieuse de la Langue Française (French Infectious Disease Society-SPILF), published recommendations on the management of Lyme borreliosis following a submission to the Director General of Health. These recommendations conflict with those of the Haute Autorité de Santé (HAS), a multi-specialties independent group of physician, on a key point: whether to add a new nosological entity labeled as "persistent polymorphous signs and symptoms (or syndrome) possibly due to tick bite." The creation of this new syndrome risks should increase anchoring bias, leading to the attribution of all symptoms to a possible tick bite, without considering differential diagnoses. Lyme disease has been extensively studied. Erythema migrans is the primary clinical manifestation. In the presence of nonmetabolic, nonseptic monoarthritis involving the knee or radiculitis of a lower limb during the summer, Lyme disease should be suspected. Serologic testing for Lyme disease is reliable in the case of late forms such as chronic arthritis, while the detection of Borrelia DNA in synovial fluid by PCR is inconsistent. Sometimes, the serology can be misleading in early forms such as radiculitis. Treatment is based on doxycycline for 14 days in early forms (radiculitis), or 28 days in late forms (arthritis). Arthritis can persist or recur after antibiotic therapy. The prevalence of a diffuse polyalgia syndrome (fibromyalgia) following Lyme disease does not seem to differ much from that in the general population. It is not improved by prolonged antibiotic therapy, which is therefore not recommended.

A phase II study of the safety of olanzapine for oxaliplatin based chemotherapy in coloraectal patients

Olanzapine has exhibited efficacy as an antiemetic agent when used with 5-HT₃ receptor antagonists, dexamethasone, and NK₁ receptor antagonists for patients receiving highly emetogenic chemotherapy. In addition, several studies have reported the efficacy or safety of olanzapine in patients receiving moderately emetogenic chemotherapy, including carboplatin, irinotecan, and oxaliplatin. However, no reports of olanzapine use have focused on patients receiving oxaliplatin-based chemotherapy. Therefore, we analyzed the safety of antiemetic therapy using olanzapine, palonosetron, aprepitant, and dexamethasone in colorectal cancer patients undergoing oxaliplatin-based chemotherapy. This study was a prospective phase II single-institution study of 40 patients (median age 60 years, 23 patients were male). The primary endpoint was the incidence of adverse events, and the exploratory endpoints were the rate of chemotherapy-induced nausea and vomiting. Almost all patients (90%) had a performance status of 0. All patients received the scheduled antiemetic therapy. The most common adverse event was somnolence (n = 7 patients, 17.5%). All adverse events were grade 1. Thirty-six patients were included in the exploratory analysis of efficacy. No patients experienced vomiting during the first 120 h after chemotherapy, and complete response and complete control were both 86.1%. The rate of total control was 55.6% during the same time period. Olanzapine use with 5-HT₃ receptor antagonists, dexamethasone, and NK₁ receptor antagonists was safe for colorectal cancer patients receiving oxaliplatin-based chemotherapy.

Tick bites in Japan

Ticks are blood-sucking ectoparasites belonging to the order Acarina, class Arachnida. In Japan, eight genera and 46 species are known. Tick bite patients frequently present to dermatology clinics. The main causative species of human tick bites are Ixodes persulcatus and Ixodes ovatus in northern to central Japan, and Amblyomma testudinarium and Haemaphysalis longicornis in western Japan. Tick bites often occur from April to September, particularly in May through July, consistent with the active period for ticks. Although erythema usually does not develop at the tick bite site, a small area of erythema may be seen in some cases. Occasionally, an erythema larger than 50 mm in diameter are formed at the bite site, known as tick-associated rash illness. It is thought that the erythema is a delayed-type allergic reaction to the substances in tick saliva. Repeated tick bites induce immunoglobulin E production against galactose-1,3-α-galactose, one of the substances in tick saliva, which may trigger an immediate allergic reaction. The most reliable method to remove a tick sucking blood is en bloc resection of the tick and surrounding skin under local anesthesia. Insect repellent spray containing icaridin or DEET are effective to prevent ticks from attaching and tick-borne infections. It is important to educate not only dermatologists but also the general public regarding tick bites.

Laboratory Diagnosis of Lyme Borreliosis

Lyme borreliosis is caused by a growing list of related, yet distinct, spirochetes with complex biology and sophisticated immune evasion mechanisms. It may result in a range of clinical manifestations involving different organ systems, and can lead to persistent sequelae in a subset of cases. The pathogenesis of Lyme borreliosis is incompletely understood, and laboratory diagnosis, the focus of this review, requires considerable understanding to interpret the results correctly. Direct detection of the infectious agent is usually not possible or practical, necessitating a continued reliance on serologic testing. Still, some important advances have been made in the area of diagnostics, and there are many promising ideas for future assay development. This review summarizes the state of the art in laboratory diagnostics for Lyme borreliosis, provides guidance in test selection and interpretation, and highlights future directions.

Lyme disease: diagnosis and treatment

PURPOSE OF REVIEW

Lyme disease is an important, vector-borne infection found throughout the temperate Northern hemisphere. The disease causes rash, acute systemic illness, and in some untreated patients, inflammatory arthritis. This review examines the emergence, clinical features and management of early Lyme disease and Lyme arthritis.

RECENT FINDINGS

There has been continuing progress in characterizing the clinical manifestations, diagnostic testing and treatment of Lyme disease. Almost all patients with early Lyme disease can be cured with antibiotic treatment. In most cases, Lyme arthritis also responds to antibiotics, but some patients require additional treatment approaches.

SUMMARY

The diagnosis of Lyme disease is based on clinical manifestations and adjunctive laboratory testing. For the rheumatologist, Lyme arthritis should be recognized by a pattern of attacks of asymmetric, oligo-arthritis, recognizable by clinical manifestations in the same way that other rheumatic diseases, such as gout or rheumatoid arthritis, are diagnosed.

Aggregation of data from 4 clinical studies demonstrating efficacy of single-dose doxycycline postexposure for prevention of the spirochetal infections: Lyme disease, syphilis, and tick-borne relapsing fever

Single-dose doxycycline, given within 72 hours of exposure, has been evaluated in 4 clinical studies for postexposure prophylaxis of 3 spirochetal infections: Lyme disease, syphilis, and tick-borne relapsing fever. In this study, data from the 4 studies were aggregated using a meta-analytic random-effects approach, with the DerSimonian-Laird method for variance estimation, analyzing a total of 2468 subjects. The findings of this analysis demonstrated an overall efficacy rate for prevention of the 3 spirochetal infections of 78% (95% confidence interval: 50%-91%).

Repurposing Disulfiram (Tetraethylthiuram Disulfide) as a Potential Drug Candidate against Borrelia burgdorferi In Vitro and In Vivo

Lyme disease caused by the Borrelia burgdorferi (Bb or B. burgdorferi) is the most common vector-borne, multi-systemic disease in the USA. Although most Lyme disease patients can be cured with a course of the first line of antibiotic treatment, some patients are intolerant to currently available antibiotics, necessitating the development of more effective therapeutics. We previously found several drugs, including disulfiram, that exhibited effective activity against B. burgdorferi. In the current study, we evaluated the potential of repurposing the FDA-approved drug, disulfiram for its borreliacidal activity. Our results indicate disulfiram has excellent borreliacidal activity against both the log and stationary phase B. burgdorferi sensu stricto B31 MI. Treatment of mice with disulfiram eliminated the B. burgdorferi sensu stricto B31 MI completely from the hearts and urinary bladder by day 28 post infection. Moreover, disulfiram-treated mice showed reduced expressions of inflammatory markers, and thus they were protected from histopathology and cardiac organ damage. Furthermore, disulfiram-treated mice showed significantly lower amounts of total antibody titers (IgM and IgG) at day 21 and total IgG2b at day 28 post infection. FACS analysis of lymph nodes revealed a decrease in the percentage of CD19+ B cells and an increase in total percentage of CD3+ T cells, CD3+ CD4+ T helpers, and naive and effector memory cells in disulfiram-treated mice. Together, our findings suggest that disulfiram has the potential to be repurposed as an effective antibiotic for treating Lyme disease.

Lyme borreliosis: diagnosis and management

Lyme borreliosis is the most common vectorborne disease in the northern hemisphere. It usually begins with erythema migrans; early disseminated infection particularly causes multiple erythema migrans or neurologic disease, and late manifestations predominantly include arthritis in North America, and acrodermatitis chronica atrophicans (ACA) in Europe. Diagnosis of Lyme borreliosis is based on characteristic clinical signs and symptoms, complemented by serological confirmation of infection once an antibody response has been mounted. Manifestations usually respond to appropriate antibiotic regimens, but the disease can be followed by sequelae, such as immune arthritis or residual damage to affected tissues. A subset of individuals reports persistent symptoms, including fatigue, pain, arthralgia, and neurocognitive symptoms, which in some people are severe enough to fulfil the criteria for post-treatment Lyme disease syndrome. The reported prevalence of such persistent symptoms following antimicrobial treatment varies considerably, and its pathophysiology is unclear. Persistent active infection in humans has not been identified as a cause of this syndrome, and randomized treatment trials have invariably failed to show any benefit of prolonged antibiotic treatment. For prevention of Lyme borreliosis, post-exposure prophylaxis may be indicated in specific cases, and novel vaccine strategies are under development.