Lyme Disease Research Articles

Gradient boosting: A computationally efficient alternative to Markov chain Monte Carlo sampling for fitting large Bayesian spatio-temporal binomial regression models

Disease forecasting and surveillance often involve fitting models to a tremendous volume of historical testing data collected over space and time. Bayesian spatio-temporal regression models fit with Markov chain Monte Carlo (MCMC) methods are commonly used for such data. When the spatio-temporal support of the model is large, implementing an MCMC algorithm becomes a significant computational burden. This research proposes a computationally efficient gradient boosting algorithm for fitting a Bayesian spatio-temporal mixed effects binomial regression model. We demonstrate our method on a disease forecasting model and compare it to a computationally optimized MCMC approach. Both methods are used to produce monthly forecasts for Lyme disease, anaplasmosis, ehrlichiosis, and heartworm disease in domestic dogs for the contiguous United States. The data have a spatial support of 3108 counties and a temporal support of 108–138 months with 71–135 million test results. The proposed estimation approach is several orders of magnitude faster than the optimized MCMC algorithm, with a similar mean absolute prediction error.

Contrasting Perceptions, Knowledge, and Actions around Lyme Disease in an Urban Area of Emerging Lyme Disease and an Area of Endemic Lyme Disease in the Northeastern United States.

Lyme disease transmission dynamics in the northeastern United States vary by context. Periurban regions, including Block Island, RI, have experienced decades of endemic transmission. In urban areas, including Staten Island, a borough in New York City, NY, Lyme disease is an emerging issue. Knowledge, attitudes, and practices around Lyme disease evolve as an area progresses from emergent to endemic. We conducted focus group discussions and household surveys within Staten Island, NY and Block Island, RI to compare knowledge, attitudes, and practices surrounding Lyme disease and other tick-borne diseases. Qualitative data were coded into themes, and survey data were used to provide more general context of the focus group discussions. Using item response theory, we developed an index of knowledge from relevant factors within the household survey. We identified a significant difference in knowledge scores between the two study areas. Additionally, we identified key differences across multiple domains. Participants from Block Island were more likely to report prior tick exposure and Lyme disease in themselves or household members and were more likely to express concerns about the environmental impact of mitigation strategies. Individuals on Staten Island were more likely to assign responsibility of prevention and control to local, state, and federal government than to take personal prevention measures. Prevention of Lyme disease and other tick-borne diseases must be tailored to the community context and monitored over time as perceptions and priorities may evolve as transmission dynamics transition from emergent to endemic.

A-299 Assessment of a new miniaturized line blot system for fully automated serodiagnosis of Borrelia infections

Abstract Background Serodiagnosis of Lyme disease caused by Borrelia burgdorferi commonly affords the combination of a sensitive antibody screening test followed by confirmatory immunoblot analysis. We developed and evaluated a new immunoblot system enabling the multiparametric analysis of anti-Borrelia antibodies by means of miniaturized line blots in a fully automated microplate format. Methods The EUROMicroblots Anti-Borrelia (IgG and IgM, EUROIMMUN) are based on diagnostically relevant Borrelia-specific antigens. Diagnostic sensitivity was determined by analyzing 203 pre-characterized samples from patients with Lyme disease stratified by clinical picture and antibiotic treatment. Specificity was assessed using 168 sera from patients clinically diagnosed with rheumatic diseases. The reference range was analyzed using a control panel of 211 (IgG) and 210 (IgM) samples from healthy individuals, comprising 151 (IgG) and 150 (IgM) blood donors as well as 60 pregnant women (IgG, IgM). The Microwell Imager and EUROLineScan software (EUROIMMUN) were used for image acquisition and evaluation. Results Depending on the clinical category, the diagnostic sensitivity of the EUROMicroblots ranged from 68.0% in the early phase of infection to 100% (IgG/IgM combined) at a specificity of 86.9% (IgG) and 94.0% (IgM). The analysis of the panel of healthy control subjects revealed a prevalence of 10.9% (IgG) and 2.8% (IgM). Conclusions The new EUROMicroblot system enables high-throughput serodiagnosis of Borrelia infections due to the microplate format and automated processing and evaluation. Depending on clinical symptoms and treatment, the assays provide excellent diagnostic sensitivity and specificity for the detection of anti-Borrelia IgG and IgM.

Climate Change and Vector-Borne Diseases: A Scoping Review on the Ecological and Public Health Impacts

Climate change is increasingly recognized as a significant driver of ecological and public health changes, particularly concerning vectorborne diseases. This scoping review aims to systematically map the current research on the impact of climate change on vector ecology and the subsequent effects on disease transmission dynamics. We conducted a comprehensive literature review across multiple databases to identify critical vectors, such as mosquitoes, ticks, and fleas. We examined how climate variables like temperature, precipitation, and humidity affect their populations, behaviors, and life cycles. Additionally, we explored the shifting geographic distributions of these vectors, investigating how climate change influences their spread and the emergence of diseases such as malaria, dengue, and Lyme disease in new regions. The review highlights the complex and multifaceted interactions between climate change and vector-borne diseases, emphasizing the necessity of understanding these relationships to inform effective public health strategies. Our findings indicate considerable variability in the impacts of climate change across different regions and vector species, underscoring the need for localized studies and tailored interventions. Moreover, significant research gaps were identified, particularly in predictive modeling, long-term surveillance, and the socio-economic impacts of vector-borne diseases exacerbated by climate change. We suggest directions for future research, including the development of integrated climate-health models and enhanced disease surveillance systems, to better anticipate and mitigate the effects of climate change on vector-borne disease transmission. This review underscores the urgency of addressing climate change as a critical component of global health initiatives and the importance of interdisciplinary approaches in tackling this complex issue. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 915-933

B-206 Tick-borne disease molecular testing positivity and coinfection incidence in the northeastern united states: 2021-2023

Abstract Background The CDC estimates that Lyme disease affects hundreds of thousands of people each year in the United States. Tick-borne diseases caused by pathogens such as Anaplasma phagocytophilum, Babesia microti, Ehrlichia chaffeensis, and species of Borrelia follow a seasonal pattern due to the life cycle of disease-carrying ticks. In endemic areas, like the northeastern United States, the risk of coinfection by multiple tick-borne disease pathogens is higher and can complicate patient treatment. For example, while Anaplasma and Borrelia can be treated with doxycycline a Babesia coinfection would not be resolved with this medication. In this study, we performed a retrospective analysis of tick-borne disease molecular testing results to monitor positivity rates and incidence of coinfection. Methods This retrospective analysis included whole blood specimens submitted to a regional clinical laboratory in the northeastern United States for tick-borne disease molecular testing. Test results from 2021-2023 were analyzed for positivity rate trends and coinfection incidence. DNA was isolated from patient specimens and tested using laboratory developed real-time Taq polymerase PCR assays. Results Positivity rates for all tick-borne disease pathogens studied followed typical seasonal patterns (Table). Beginning in the early spring, as nymphs ended their dormancy and began to feed, infection rates of tick-borne disease climbed. Infections peaked in mid-summer and remained elevated through late autumn. For Anaplasma, a biphasic pattern was observed, with a smaller peak in late autumn when adult ticks are most active. Coinfections with Anaplasma and Babesia were observed in 136 specimens, while coinfections with Borrelia and Babesia were observed in 145 specimens. Conclusions Positivity rates for tick-borne disease pathogens followed expected seasonal patterns in the northeastern US. The incidence of coinfections involving Babesia microti highlights the importance of properly identifying tick-borne infections given the different treatment regimens indicated.

Age- and Sex-Specific Differences in Lyme Disease Health-Related Behaviors, Ontario, Canada, 2015-2022.

We investigated differences in risk factors and preventive behaviors by age and sex among persons with reported Lyme disease in Ontario, Canada, during 2015-2022. Incidence rates peaked among children 5-9 and adults 50-79 years of age. Median age was higher for female than male case-patients (54 vs. 51 years). Male case-patients reported more activity in wooded and tall grass areas than did female case-patients; fewer male case-patients reported sharing living space with outdoor-exposed companion animals. As age increased, more case-patients reported activity in blacklegged tick habitats, exposure to ticks, and wearing adequate clothing, but fewer reported sharing living space with outdoor-exposed companion animals. Adoption of preventive behaviors was relatively low and did not differ by sex. Male case-patients, children 5-9 years of age and their parents or caregivers, and adults >59 years of age represent populations that would benefit from tailored public health messaging on Lyme disease prevention.

Vector-Borne Diseases Potpourri.

The Intergovernmental Panel on Climate Change has reported that the prevalence of vector-borne diseases has increased in recent decades and that the prevalence of malaria, Lyme disease, dengue, and, in particular, West Nile virus infection are expected to increase further if control measures are not strengthened. (1)(2) This review article summarizes the epidemiology, various clinical manifestations, and management strategies of these vector-borne diseases with increasing prevalence both in the United States and worldwide.

Detection of Borrelia burgdorferi sensu lato by proteomics: a complementary diagnosis tool on erythema migrans biopsies

ObjectivesWe have developed targeted proteomics in the context of Lyme borreliosis (LM) as a new direct diagnostic tool for detecting Borrelia proteins in the skin of patients with erythema migrans. If satisfactory, this proteomic technique could be used in addition to culture and/or PCR for disseminated infections where Borrelia detection is essential to demonstrate active infection. In these infections, the diagnosis is indirect and relies mainly on serology. MethodsWe recruited 46 patients with LM and 11 controls and collected two skin biopsies from each patient. One biopsy was used for Borrelia burgdorferi sensu lato PCR and culture and the other one was for targeted mass-spectrometry-based proteomics. Six markers of infection were selected for proteomics: OspC, flagellin, enolase, lipoprotein gi|365823350, decorin binding protein A, and glyceraldehyde-3-phosphate dehydrogenase. ResultsCulturing Borrelia from the biopsies increased the sensitivity of the methods. Among the patients included for analysis, 61% (28 patients), 61% (28), and 46% (21) were detected as positive by proteomics, PCR, and culture, respectively. PCR and proteomics were complementary. OspC and flagellin were the most frequently detected protein markers of infection by proteomics, which in some patients, detected up to nine peptides for the flagellin. DiscussionIt is possible to identify bacterial makers from the skin by proteomics. Our approach can be used to diagnose tick-borne diseases such as LM. Trial registrationclinicaltrials.gov identifier: NCT02414789.

Surveillance data from 2011-2020 indicate alower risk of Lyme disease in the USA in even-numbered years.

From 2011-2020 the number of reported cases of Lyme disease in the USA was lower in each even-numbered year compared with the preceding odd-numbered year. This observation suggests that fewer nymphal stage Ixodes scapularis ticks infected with Borrelia burgdorferi were present during even-numbered years in locations where people spend time.

A modified matrix model captures the population dynamics for the primary vector of Lyme disease in North America

AbstractLyme disease, the most prevalent tick‐borne disease in North America, is caused by the bacterium Borrelia burgdorferi, and in the eastern and central United States, it is spread to humans by the black‐legged tick (Ixodes scapularis). Due to the complex, multiyear and multihost life cycle of this species, a matrix modeling approach is needed to effectively estimate subseasonal, multistage survival and transition dynamics in order to better understand and predict when population growth is high. Of the three questing tick life stages (larvae, nymphs, and adults), nymphs are most often associated with transmitting the bacteria to humans, and previous work suggests a mix of abiotic and biotic drivers are associated with nymph abundance. However, understanding tick population growth requires understanding mortality and transition probabilities for each stage and each stage may be individually and uniquely impacted by climate and host availability. A larval tick, for example, may experience warming temperatures differently than nymph or adults, because they are present on the landscape at different times. Here, we describe and validate a model that accounts for field sampling design and evaluates abiotic (temperature, relative humidity, precipitation) and biotic (host abundance) drivers of variation in tick population growth. To account for the drivers of subseasonal and interannual variability in demography, phenology, and population density, we built stage‐structured population models that account for variability in meteorology and host population abundance throughout the full tick lifecycle. Our model is fit and validated with 11 years of tick and host data from the northeastern United States. In this context, we found that a four‐stage model that includes unique transitions to and from a dormant, overwintering nymph state outperforms a model that only includes the three questing stages, and that incorporating the abundance of the predominant host species, Peromyscus leucopus, and weather variables improved predictions and model fit. Additionally, the model accurately predicted all three questing stages at sites different than where they were calibrated, showing that this model structure is generally transferable. Overall, this model lays a foundation for the real‐time iterative forecasting of tick populations needed to effectively protect public health.

UNFORESEEN BARRIER IN GOUT TREATMENT: A CASE OF COEXISTING LYME DISEASE

Refractory gout and Lyme disease are distinct conditions that, when coexisting, pose significant diagnostic and therapeutic challenges, particularly in regions endemic for Lyme disease. This case report presents a 49-year-old male with a three-year history of gout, presenting with acute arthritis of the first metatarsophalangeal joint, unresponsive to standard urate-lowering therapy. Despite treatment with colchicine and prednisone, the patient’s symptoms persisted, and inflammatory markers remained elevated. Imaging revealed findings consistent with gouty arthritis, but due to the atypical treatment response, further testing was conducted. Serological analysis confirmed infection with Borrelia burgdorferi, establishing the diagnosis of concurrent Lyme disease. The addition of doxycycline to the treatment regimen resulted in significant clinical improvement within days. This case highlights the importance of considering Lyme disease in patients with refractory gout in areas endemic for Lyme disease. While rare cases of Lyme disease mimicking gout have been reported, this is among the first documented instances of their coexistence. Early recognition and appropriate antibiotic treatment are critical in preventing complications and ensuring optimal management of both conditions.

Maximizing and sustaining the efficacy of tick tubes for management of Ixodes scapularis through optimized deployment strategies.

The number of tick-borne disease cases continues to rise in the United States, with Lyme disease the most frequently reported vector-borne disease nationally. Practical and effective tick control tools and strategies are needed to reduce tick encounters and tick-borne disease risk. Tick management tubes have shown varying efficacy when used as part of a tick management plan. To evaluate factors contributing to the efficacy of tick management tubes, this study assessed changes in tick tube deployment on tick burden on wild-caught Peromyscus mice, a primary reservoir for the bacterium causing Lyme disease, in Pennsylvania from 2021 to 2023. Over 2 years, tick tubes were deployed starting at different times of the year, with cotton removal from the tubes assessed every 2 weeks from April to November and tick burden on wild-caught mice assessed every 2 months from April to October of each year. The effect of distance between tick management tubes was assessed in year 3 of this study, with mouse tick burden assessed pre- and post-treatment with tick tubes at varying intervals in a field setting. There was a significant reduction in mouse tick burden between treated and control transects, and pre- and post-treatment transects. Tick tube distance did not affect cotton removal or tick burden on mice. Still, cotton removal was highest in September-October, and amount removed increased the longer tick tubes were deployed in the field, highlighting the long-term benefits of using tick tubes as part of an integrated tick management plan. Future investigations to evaluate the impact of tick management tubes on tick nymph density and infection would be valuable for assessing the effectiveness of tick management tubes in reducing tick bite risk.

First reported cases of Borrelia and dengue co-infection: A case series.

Dengue fever is one of the most common diagnoses in patients presenting with acute febrile illness in tropical countries. Borrelia, on the other hand, is the cause of vector-borne infections of relapsing fever and Lyme disease. While co-infections of dengue with chikungunya, Zika, malaria, influenza and typhoid have been reported, clinical cases of Borrelia infections have never been reported in Malaysia. Based on available evidence, this is the first case series to report dengue fever and Borrelia spp. co-infection. All three patients in this report were admitted to medical wards on day 3 to day 8 of illness for dengue fever as evidenced by a positive dengue NS1 antigen test. The clinical manifestations were typical of dengue fever, with all patients having high grade fever, myalgia, and arthralgia. All patients also had thrombocytopenia. Features of severe dengue, such as shock, hemorrhage and impaired consciousness were absent. Borrelia DNA were detected in the blood samples of the patients. However, all the patients denied having skin lesions and a history of insect bites. All the patients were given intravenous fluid therapy and were discharged after 3 to 5 days of hospitalization.

Vector-borne diseases in Cyprus: A detailed review of the literature.

Vector-borne diseases have been a growing health concern in recent decades due to the global warming, globalization, and increased international travel. With the typical Mediterranean climate and geographical features, Cyprus provides favorable conditions for the growth and survival of arthropod species. For the purpose of this review article, the terms "Cyprus", "vectors" and "vectorborne diseases" were searched in the National Library of Medicine ('PubMed') and the Google Scholar databases. Published articles in the literature have documented mosquito (including Anopheles, Aedes, Culex, and Culiseta), sandfly (Phlebotomus, Sergentomyia), flea (including Ctenocephalides, Xenopsylla, Leptopsylla), and tick (including Rhipicephalus, Ixodes, Hyalomma, Haemaphysalis) species in the island. The presence of these arthropods poses a risk to public health as they can transmit a variety of diseases to both humans and animals. Research studies in Cyprus have identified infectious agents such as West Nile virus, Leishmania spp., sandfly viruses, Rickettsia spp., Coxiella burnetii, and Bartonella spp. in the local arthropods. More importantly, West Nile virus infection and imported malaria cases (mosquitoborne diseases); leishmaniasis and sandfly fever (sandfly-borne diseases); rickettsiosis, tularemia, Q fever, anaplasmosis, tick-borne relapsing fever, and Lyme disease (tick-borne diseases); and flea-borne rickettsiosis were reported in Cyprus. Taken together with the presence of arthropod vectors, published evidence in the literature suggests that Cyprus is an important region for VBDs. In addition to its climatic and geographical conditions, international travels particularly from endemic countries pose a risk for the circulation of VBDs on the island. Therefore, vector control programs should be continuously implemented, and public awareness must be raised in the region. This review, which to the best of our knowledge is the first comprehensive report on VBDs from Cyprus, will provide insight into future islandwide studies and also will be an important contribution to the elimination of VBDs in the region.

Lyme Disease Prophylaxis by Single-Dose Doxycycline in the United States, 2010-2020.

Single-dose doxycycline after high-risk tick bites can prevent Lyme disease, which disproportionately affects children. We described single-dose doxycycline dispensings in an outpatient cohort in the United States. During 2010-2020, a total of 427 105 patients received ≥1 dispensing(s); most were aged ≥65 years. Lyme disease postexposure prophylaxis may be underprescribed for some groups, including children.

Pregnancy Among Reported Lyme Disease Cases-United States, 1992-2019.

Lyme disease (LD), the most common vector-borne disease in the United States, typically presents with a localised erythema migrans rash (EM). Left untreated, infection can disseminate to cause severe heart, joint or nervous system manifestations. Summaries of LD surveillance data have been published previously but did not include the frequency, demographic or clinical characteristics of LD cases during pregnancy. We summarised confirmed and probable LD cases by pregnancy status as reported to the U.S. Centers for Disease Control and Prevention during 1992-2019. We defined an LD case during pregnancy as one with (1) female sex, (2) age 14-49 years and (3) positive pregnancy indication. We evaluated the frequency, seasonality, age distribution, race and ethnicity, geographic distribution and clinical manifestations of LD cases during pregnancy and cases among non-pregnant females. We compared proportions using chi-squared tests. Among 698,876 reported LD cases, 112,002 (16%) were confirmed or probable cases among females aged 14-49 years; 32,301 (29%) were specifically reported as non-pregnant and 643 (0.6%) (568 confirmed and 75 probable cases) reported as pregnant. Illness onset peaked in June among LD cases during pregnancy, but in July for cases among non-pregnant females. A higher proportion of confirmed LD cases during pregnancy had only EM rash than did cases among non-pregnant females (66% vs. 60%, p = 0.019). LD cases during pregnancy are rare. Compared to non-pregnant females, cases among pregnant females more commonly involve early clinical manifestations. These patterns could suggest earlier detection or more complete reporting of LD cases during pregnancy than their non-pregnant counterparts. Earlier detection could be due to frequent contact with healthcare or increased self-advocacy during pregnancy. Prompt antimicrobial treatment is critical for preventing severe disease and reducing risk of adverse pregnancy or birth outcomes.

Complement therapeutic Factor H-IgG proteins as pre-exposure prophylaxes against Lyme borreliae infections.

Lyme disease (LD) is the most common vector-borne disease in the northern hemisphere and is caused by the bacteria Borrelia burgdorferi sensu lato (also known as Lyme borreliae) with no effective prevention available. Lyme borreliae evade complement killing, a critical arm of host immune defense, by producing outer surface proteins that bind to a host complement inhibitor, factor H (FH). These outer surface proteins include CspA and CspZ, which bind to the 6th and 7th short consensus repeats of FH (SCR(6-7)), and the OspE family of proteins (OspE), which bind to the 19th and 20th SCR (SCR19-20). In this study, we produced two chimeric proteins, FH-Fc, containing the Fc region of immunoglobulin G (Fc) with SCR(6-7) or SCR(19-20). We found that both FH-Fc constructs killed B. burgdorferi in the presence of complement and reduced bacterial colonization and LD-associated joint inflammation in vivo. While SCR(6-7)-Fc displayed Lyme borreliae species-specific bacterial killing, SCR(19-20)-Fc versatilely eradicated all tested bacterial species/strains. This correlated with SCR(6-7)-Fc binding to select variants of CspA and CspZ, but SCR(19-20)-Fc binding to all tested OspE variants. Overall, we demonstrated the concept of using FH-Fc constructs to kill Lyme borreliae and defined underlying mechanisms, highlighting the potential of FH-Fc as a pre-exposure prophylaxis against LD infection.

Borrelia burgdorferi infections in children and adolescents in Switzerland - a seroprevalence study 2023/2024 (BOBUINCA).

Lyme borreliosis is one of the most prevalent tick-borne diseases in Europe. Studies on seroprevalence of Borrelia burgdorferi IgG antibodies in children are rare. The aim of this study was to determine the seroprevalence of B. burgdorferi IgG antibodies in children and adolescents residing in North-Western Switzerland and neighbouring countries. Prospective cross-sectional observational single-centre study using left-over plasma of asymptomatic paediatric patients. Included were children aged 1-17 years living in North-Western Switzerland and bordering areas of France and Germany. Excluded were children with symptoms of Lyme borreliosis or a chronic disease possibly affecting plasma antibodies (immunodeficiency syndrome, systemic lupus erythematosus) or with such medication (e.g., intravenous immunoglobuline treatment, allogenic stem cell transplantation, immunosuppressive treatment) as well as refugees seeking asylum. IgG antibodies against B. burgdorferi were measured by ELISA and positive or borderline results by line blot. Positivity was defined as scenario 1: ELISA positive/line blot positive or borderline OR ELISA borderline/line blot positive. Scenario 2: ELISA positive or borderline/line blot positive. A multivariable logistic regression model for seropositivity was applied. 962 children were included (mean age 9.63 years, standard deviation 5.01, 54.5% males). Seroprevalence for scenario 1 was 13.3% (95% CI: 11.2-15.6) and for scenario 2 11.2% (95% CI: 9.3-13.4). Seroprevalence (scenario 1) was comparable for age groups, sex and rural versus urban residence. This study shows an increased seroprevalence for B. burgdorferi in the paediatric age compared to previous childhood studies. We also found an increased risk for B. burgdorferi infection at young age.

Barriers to the Uptake of Tickborne Disease Prevention Measures: Connecticut, Maryland 2016-2017.

Public health programs promote numerous tickborne disease (TBD) prevention measures. However, measures are not frequently or consistently performed. Describe barriers to consistent use of 4 commonly promoted TBD prevention measures. We conducted an online survey (n=1883) evaluating behaviors regarding TBD prevention measures including conducting tick checks, applying insect repellents, showering/bathing, and applying chemical or natural pesticides to residential yards. Respondents could select reasons for never, rarely, or sometimes performing these measures. Descriptive analysis and logistic regression modeling evaluated associations between the 3 most cited barriers for each measure and select demographic variables. The survey was administered to residents in high Lyme disease incidence counties of Connecticut and Maryland, 2016-2017. For tick checks (n=800), the most cited barriers were forgetting (63%), not spending time in tick habitat (28%), and too much trouble (11%). For applying insect repellents (n=1303), the most cited barriers were forgetting (38%), personal safety concerns (24%), and too much trouble (19%). For showering/bathing 2 hours after outdoor activity in tick habitat (n=1080), the most cited barriers were being unaware of the prevention measure (51%), too much trouble (18%), and forgetting (18%). For applying chemical pesticides to yards (n=1320), the most cited barriers were having environmental (45%), pet safety (31%), and personal safety concerns (28%). Lastly, for applying natural pesticides to yards (n=1357), the most cited barriers were being unaware of natural pesticides (31%), having cost concerns (23%), and not being concerned about ticks on property (16%). Forgetting, too much trouble, unawareness, and safety concerns were primary barriers to using several TBD prevention measures. Education regarding effectiveness, safety, and timing may increase uptake of certain measures. These challenges can be difficult to address, highlighting the need for passive TBD prevention measures, such as a Lyme disease vaccine.

Hemophagocytic Lymphohistiocytosis Secondary to Anaplasmosis With Lyme Coinfection

Abstract Human granulocytic anaplasmosis and Lyme disease are tick-borne infections transmitted by the same vector, Ixodes scapularis, commonly isolated in areas within the Midwest region of the United States. Although typically associated with mild symptoms, both can progress to severe disease. Treatment of choice for a majority of tick-borne illness is doxycycline; however, options are limited in the setting of tetracycline allergy. Here, we present a complex case of human granulocytic anaplasmosis–induced hemophagocytic lymphohistiocytosis complicated by coinfection with Lyme encephalitis in a patient with a documented tetracycline allergy.