Tick-borne Diseases Research Articles

Rickettsia rickettsii subsp. californica subsp. nov., the etiologic agent of Pacific Coast tick fever.

The etiologic agent of Pacific Coast tick fever (PCTF), a moderately severe tickborne illness that resembles Rocky Mountain spotted fever (RMSF), was first isolated in 1966 from specimens of Dermacentor occidentalis (the Pacific Coast tick) obtained in California. For several decades, this bacterium was identified ambiguously as the unclassified spotted fever group Rickettsia species 364-D, Rickettsia 364, or Rickettsia philipii. However, none of these epithets satisfied criteria of formal bacterial nomenclature. Data developed from mouse serotyping studies performed 45 years ago, and multi-locus sequence typing several decades later, indicated that this bacterium was similar to, but distinct from isolates of Rickettsia rickettsii, the etiological agent of RMSF. We applied an integrative taxonomic approach, combining phenotypic, ecological, and clinical data with whole genome sequencing of 11 contemporary isolates of this pathogen to identify it as a distinct subspecies of R. rickettsii, and propose the name Rickettsia rickettsii subsp. californica subsp. nov.

Crimean Congo hemorrhagic fever virus exposure among febrile patients, cattle herders, and cattle herds in Cameroon

Problem addressedCrimean Congo hemorrhagic fever (CCHF) is a tick-borne disease with high fatality rates and an expansive geographic distribution, yet disease prevalence data in Cameroon is lacking. ObjectiveThis study aimed to determine CCHF virus (CCHFV) seroprevalence and tick distribution among cattle herders and febrile patients in West and Centre Cameroon. Methods and approachTwo cross-sectional serological studies of human and cattle were conducted from October to December 2021 and from June to July 2022, which included the collection of ticks. Enzyme-linked immunosorbent assay (ELISA) were used to detect anti-CCHFV antibodies, while a knowledge, attitudes, and practice (KAP) survey assessed tick and tickborne disease related knowledge and behaviors among herders. Tick identification used morphological keys. ResultsThe KAP survey showed adequate tick knowledge (94.5 %) among herders but poor understanding of disease transmission, with favorable attitudes towards tick control (24.7 %) but inadequate implementation. Rhipicephalus annulatus (64.1 %) predominated among the 1,296 ticks collected during each rainy season. Among cattle, 27.4 % were seropositive, and seropositivity was associated with specific villages, cattle age (>4 years), and female sex. Herders had a 17.8 % seroprevalence, while febrile patients had 8.3 %, with higher rates in those >20 years old for both groups. Self-reported tick removal by herders after contact and grazing may increase CCHFV exposure. ConclusionsThis study confirms CCHFV circulation in rural West Cameroon and unexpected exposure risk in Yaounde, highlighting the need for active entomological surveillance and preventive measures in transhumance and cattle market activities. Establishing an occupation-based surveillance system can help identify CCHFV hotspots to prevent outbreaks.

Associations between Ornithodoros spp. Ticks and Mojave Desert Tortoises (Gopherus agassizii) Obtained from Health Assessment Documents.

Soft ticks in the genus Ornithodoros occur throughout the Mojave Desert in southern Nevada, southeastern California, and parts of southwestern Utah and northwestern Arizona, USA, and are frequently observed parasitizing Mojave desert tortoises (Gopherus agassizii). However, limited research exists examining the relationship between ticks and desert tortoises. Mojave desert tortoises are listed as threatened by the US Fish and Wildlife Service, and as such, their populations are monitored and individual tortoise health is routinely assessed. These health assessments document the presence and abundance of ticks present on tortoises, but detailed examination of the relationship between ticks and tortoise health has been lacking. This study analyzed the relationship between tick presence and desert tortoise health assessments as a function of season, location, age (adult vs. juvenile), foraging behavior, evidence of clinical signs of disease, body condition score, and sex. Our results indicate that more ticks were found on tortoises in the summer than in any other season. Ticks were observed more frequently on captive tortoises versus wild tortoises, and more ticks were likely to be present on adult tortoises than on juveniles. Ticks were also more likely to be observed on tortoises that lacked evidence of foraging and on tortoises with observed clinical signs of disease. These findings provide valuable insights into the biology of ticks in relation to tortoises that may be useful for management of both captive and free-living threatened tortoise populations where ticks are detected. Our study also may improve understanding of potential tick-borne disease dynamics in the Mojave desert tortoise habitat, including Borrelia sp. carried by Ornithodoros ticks, which cause tick-borne relapsing fever in people.

In vitro assessment of assembly and sex pheromones in the control of larval stages of brown dog ticks

The increasing incidence of tick-borne diseases and the growing resistance to conventional acaricides underscore the urgent need for innovative and sustainable tick management strategies. This study investigates the potential of assembly and sex pheromones for the control of larval stages of Rhipicephalus sanguineus, the brown dog tick, which poses significant health risks to dogs. The ticks were collected from various canine hosts in Thrissur, Kerala and subjected to Petri-dish bioassays using vapour patches impregnated with synthetic assembly pheromone (AP) and sex pheromone (SP), both individually and in combination. The efficacy of these semiochemicals was assessed based on the attraction and clustering behaviour of unfed larvae and partially fed adult ticks over a 24-hour period. Results demonstrated a significantly higher attraction to AP-impregnated patches, with notable efficacy observed in causing tick aggregation, particularly beyond 30 min of exposure. While SP also showed potential in attracting ticks, the combination of SP and AP did not result in a synergistic effect. The study highlights the potential of using semiochemicals as an environmentally sustainable alternative to traditional acaricides, highlighting their role in integrated pest management strategies Keywords: Rhipicephalus sanguineus, adenine, guanine, xanthine, 2,6-DCP, Petri-dish bioassay

Efficacy of CP-COV03 (a niclosamide-based inorganic nanohybrid product) against severe fever with thrombocytopenia syndrome virus in an in vitro model.

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease caused by the SFTS virus (SFTSV). CP-COV03 is a novel antiviral candidate that significantly enhanced the bioavailability of niclosamide through inorganic-based drug delivery technology. The active pharmaceutical ingredient of CP-COV03, niclosamide, has been previously shown to possess broad-spectrum antiviral activity against over 30 different viruses in the in vitro tests. The aim of this study is to confirm the antiviral activity of CP-COV03 against the SFTSV in an in vitro model. Vero cells and SFTS viral stock NCCP43270, a 2015 Gangwon Province isolate, were used to obtain the 50% tissue culture infective dose of the virus. Vero cells seeded in 96-well plates were infected with SFTSV for 1 h. SFTSV-infected cells were treated with CP-COV03 at various concentrations of 0.1-100 μM and incubated for 7 days. On the seventh day of the culture, the cytopathic effect (CPE) of SFTSV was checked by microscopy and the cell viability was checked by using Cell Counting Kit-8 assay. The CPE reduced as the CP-COV03 concentration increased. The 50% inhibitory concentration (IC50) range of CP-COV03 was below 0.125 µM, as determined from the viral titers of culture supernatants collected on the third day posttreatment of CP-COV03. The plaque reduction assay showed that the IC50 of CP-COV03 was 1.893 µM, as determined from the percentage reduction of plaque counts for each drug concentration on the second day posttreatment with CP-COV03. This study suggests that CP-COV03 could be used as a potential antiviral agent for SFTS.IMPORTANCEWe demonstrated a concentration-dependent response and identified low a IC50 of CP-COV03. This result is comparable to other antiviral drugs used against viruses like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We believe that our study makes a significant contribution to the literature as our findings suggest that CP-COV03 may serve as a potential treatment for SFTS, highlighting its importance in the field of antiviral research.

Abundance Trends of Immature Stages of Ticks at Different Distances from Hiking Trails from a Natural Park in North-Western Italy.

Hiking trails may act as hotspots at the wildlife-human interface, posing an acarological risk for people and their pets. Ticks that are maintained in the environment by wild animals may quest on people walking along the trails. Assessing the risk of tick bites for people involved in outdoor activities is a further step in mitigating the risk of tick-borne diseases. This work describes the variation of tick abundance along a gradient of distances from hiking trails, where wildlife passage is favored by higher accessibility. Hiking trails with dense vegetation on the sides were sampled for ticks along a 100 m dragging transect, located in a natural park in North-Western Italy. Additional transects were replicated at 1, 2 and 4 m away from the trail on both sides. After morphological identification, descriptive statistics and modeling were applied to determine the abundance patterns across distances. Larvae were most abundant near the trail, peaking at 1 m and dropping sharply at further distances. Nymphs showed a more gradual and consistent decrease at progressing distance from the trail. Few adults were collected, preventing the identification of a clear trend. With higher tick abundance, the immediate vicinity of hiking trails may represent a source of acarological risk for humans and pets.

A Case of Tick-borne Disease with Yezo Virus and Borrelia miyamotoi Coinfection.

Yezo virus is a novel virus transmitted by tick bites that causes fever with thrombocytopenia. To date, two reports have been published on patients with Yezo virus infection. However, the clinical characteristics of Yezo virus infection remain unclear. A patient who presented with fever, fatigue, headaches, and muscle pain and was admitted to our hospital. The patient had thrombocytopenia, leukopenia, and elevated liver enzyme and serum ferritin levels. The patient was diagnosed with Yezo virus and Borrelia miyamotoi coinfection based on the detection of Yezo virus in a blood sample by PCR and the detection of elevated serum antibody titers to Yezo virus and Borrelia miyamotoi.

Multifaceted Interventions to Enable Elimination of Clinician-ordered Blood Smear Reviews: A Rural Academic Medical Center Experience

Abstract Introduction/Objective Blood smears (BS) evaluate a variety of clinical disorders. At Geisinger, clinician ordered pathologist review of blood smears (CBS) have increased despite usage of highly sophisticated hematology analyzers and automatic blood smear (ABS) review criteria. We hypothesized that CBS impact pathologists’ and technologists’ workloads and increase costs and turn-around times, with rare improvement in value-based patient care. This study aimed to analyze CBS ordering practices and improve the utilization of BS review. Methods/Case Report In October 2020, a prospective CBS utilization study was completed by 8 clinical pathologists for 172 CBS. Subsequently, a clinical question was required for CBS orders from January 1, 2022, to January 1, 2023, to investigate clinician ordering practices based on campus, department, and indications. Findings were used to support new interventions including: clinician education; cancellation of repeat BS ordered within 24 hours, creation of alternative tests (schistocyte technologist smear review, clinician order for independent slide review), standardization of morphology reporting, ABS audits, and elimination of orderable CBS replaced by an electronic BS review request, that is reviewed by a clinical pathologist prior to determine if a BS is indicated. Results (if a Case Study enter NA) Part of the Conclusions section for Lab Practice abstract. Conclusion Prospective utilization audit of 172 CBS orders showed 17% changed clinical management. Audit of 3,693 CBS orders demonstrated common reasons for review included tick-borne illness, hemolysis, erythrocytosis, thrombocytosis, and iron deficiency anemia. Systematic implementation of multiple interventions enabled the elimination of CBS, with no known adverse effect on patient management to date. The streamlined BS review guidelines allowed for better-allocation of resources, appropriate patient turn-around times, empowerment of laboratory technologists and reduced hospital costs. We propose maximizing the incorporation of technologist skills to improve the utilization and efficiency of BS reviews and establishing standardized, evidence-based, and institutional- specific guidelines to determine BS reviews.

Unveiling Misconceptions among Small-Scale Farmers Regarding Ticks and Tick-Borne Diseases in Balochistan, Pakistan

Ticks and tick-borne diseases (TBDs) pose potential health threats to small-scale farmers of grazing animals in the upper highlands of Balochistan, Pakistan. This study was conducted based on a questionnaire survey involving 153 farmers of grazing animals in seven districts to access their knowledge, attitudes, and practices regarding ticks and TBDs. Odds ratios and 95% confidence intervals, based on Fisher’s test, were used to assess risk factors for determining preventive measures. The findings revealed a low level of knowledge among the participants. For instance, there was a lack of awareness of the effects of climate change and the economic impact of ticks on animal health. The essential precautions, such as the non-indiscriminate use of acaricides, wearing dark-colored clothing, and limiting children’s interaction with grazing animals, were often overlooked. However, the farmers had a positive attitude towards tick control, but they mostly relied on the knowledge of local communities. The neglect of such measures places these farmers and their children at risk of contracting TBDs. This study also indicates minimal involvement from the government in educating farmers and controlling ticks. The role of stakeholders, including the government, non-governmental organizations, veterinary doctors, and local farmer communities, is crucial to address these issues and to implement effective training programs that address misconceptions about ticks and TBDs. Overall, this study highlights the importance of implementing awareness and education programs to address the misconceptions about ticks and TBDs among farmers.

Highly Sensitive Molecular Diagnostic Platform for Scrub Typhus Diagnosis Using O. tsutsugamushi Enrichment and Nucleic Acid Extraction.

Scrub typhus is caused by the Gram-negative obligate intracellular bacterium Orientia tsutsugamushi, and this tick-borne disease is difficult to distinguish from other acute febrile illnesses as it typically presents with symptoms such as rash, crusting at the bite site, headache, myalgia, lymphadenopathy, and elevated liver transaminases. It can often be diagnosed clinically, but not all patients present with characteristic symptoms, so serological diagnosis and molecular techniques may be required. However, existing diagnostic tests often have low sensitivity and specificity, making early detection difficult. This study presents a nucleic acid extraction method using large volumes of plasma and buffy coat to increase sensitivity, as well as an improved detection method using two target genes. Using the I-PULL device, nucleic acids can be extracted from up to 4 mL of sample in 30 min, avoiding contamination. The extracted DNA detects two genes of O. tsutsugamushi, increasing sensitivity compared to single-gene detection. Clinical validation in 38 patient samples showed 100% specificity and 95.24% sensitivity for the single target gene, with specificity and sensitivity rising to 100% when both genes are analyzed. This molecular diagnostic platform can be useful for distinguishing scrub typhus from similar diseases.

Rocky Mountain Spotted Fever Encephalitis and "Starry Sky" Pattern on MRI: A Case Report.

Rocky Mountain Spotted Fever (RMSF) is a tick-borne disease caused by Rickettsia rickettsii (R. rickettsii). RMSF presents after a tick bite with fever, rash, and headache but can also cause more serious neurological manifestations. We report a case of RMSF encephalitis presenting with altered sensorium and rapid progression to coma, fever, and petechial rash, and an magnetic resonance imaging (MRI) brain notable for a "starry sky" pattern. A 61-year-old woman presented with confusion and fever and was diagnosed with a urinary tract infection. Two days later, she became comatose. MRI brain revealed lacunar infarcts in the right centrum semiovale and splenium of the corpus callosum. Lumbar puncture was notable for neutrophilic pleocytosis and elevated protein with negative bacterial and viral cultures. Empiric meningitis therapy was initiated, and she was transferred to our institution. On transfer, she was febrile, comatose, and had a diffuse petechial rash. Repeat MRI brain demonstrated diffuse, innumerable punctate foci of diffusion restriction with susceptibility-weighted signal attenuation throughout cerebral hemispheres in a "starry sky" pattern. Skin biopsy revealed perivascular lymphocytic infiltrates. Serologic RSMF antibody titers were obtained, and doxycycline was initiated for presumed RMSF encephalitis. The family opted to pursue palliative measures, given no clinical improvement. RSMF titers and postmortem PCR from brain tissue were positive for R. rickettsii. This case report highlights the clinical presentation of RMSF encephalitis. RMSF encephalitis should be suspected in a patient presenting with encephalopathy, fever, petechial rash, and MRI brain findings of diffuse punctate foci of diffusion restriction and susceptibility-weighted signal attenuation in a "starry-sky" pattern.

A systematic review and meta-analysis of the prevalence of tick-borne SFGR in China from 2000 to 2022.

Ticks carry and transmit a wide range of pathogens (bacteria, viruses, and protozoa) that pose significant threats to human and animal health worldwide. Only few meta-analyses have been conducted on the distribution of ticks and tick-borne spotted fever group rickettsia (SFGR). Therefore, this study aims to examine the tick species and SFGR positivity in China in order to provide support for further research and improvements in the prevention and control of tick-borne diseases. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant Chinese and English studies were retrieved from PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), VIP database, Chinese Biomedical literature database (CBM) and Wanfang database from inception to January 9, 2023. Pooled SFGR positive rate was meta-analyzed using a random effects model and heterogeneity was assessed by the I2 index. Publication bias was also evaluated by funnel plot and Egger's test. The meta-analysis was performed on R studio 4.0.4. Meta-analysis of 57 studies published between 2000 and 2022 involving 39,380 ticks revealed a pooled SFGR positive rate of 21.4% (Q = 6423.74, I2 = 99%, Q-p<0.001, 95% CI: 15.0-29.6). Most studies of tick-borne SFGR infection rate were conducted in forest areas and developed animal husbandry areas in the northern region. There were slightly more tick species in the southern region, but the differences in tick species (Feeding tick 31.5%, 95%CI: 15.7-53.2, Questing tick 11.5%, 95%CI: 4.4-26.7, Q = 3.29, Q-p = 0.19) between areas (Northern area 20.4%, 95%CI: 14.1-28.7, Southern area 25.5%, 95%CI: 15.0-29.6, Q = 0.21, Q-p = 0.64) were not statistically significant. The most common tick species were Dermacentor silvarum (13%), Ixodes persulcatus (11%) and Haemaphysalis Iongicornis (10%), and the most prevalent SFGR species were Rickettsia raoultii (20%), Rickettsia heilongjiangiensis (11%), and some uncultured species (18%). This study examined the distribution of tick-borne SFGR in China. Our findings revealed that the main tick species were D. silvarum, I. persulcatus and H. iongicornis, and the common SFGR species were R. raoultii, R. heilongjiangiensis, and some uncultured species. Further studies are warranted to identify the potential vectors of SFGR and to better understand the epidemiology and pathogenesis of tick-borne diseases in China.

Microbial community characteristics and pathogens detection in Rhipicephalus sanguineus and Haemaphysalis hystricis from Hainan Island, China.

Microbial communities significantly influence the vector capacity of ticks, which, along with tick-borne diseases, pose an increasing global threat. Due to the substantial individual variability caused by various factors, it is essential to assess tick microbial communities and vectorial capacities under different environmental conditions. However, there is a relative scarcity of research on the microbial communities and pathogen transmission of ticks in different physiological states and environmental conditions, especially in Hainan Island, southern China. From 2021 to 2022, we collected 4,167 tick samples, grouping them by blood meal status, developmental stage, sex, time, geographical location, and tick species. We selected 128 samples for full-length 16S rRNA sequencing to describe microbial community characteristics and identify potential biomarkers. Seven hundred seventy-two samples were tested for seven tick-borne pathogens (Rickettsia, Borrelia burgdorferi, Ehrlichia, Anaplasma, Theileria, Babesia, and Hepatozoon), and sera from 208 residents of Hainan Island were tested for IgG antibodies against Rickettsia and B. burgdorferi. Blood meal status, developmental stage, sex, time, geographical location, and tick species significantly influenced the microbial communities of ticks. We observed distinct microbial community characteristics across different states. We noted the non-random replacement of stable and transient species, with functional differences between parasitic and engorged ticks mainly driven by transient species. Functionally, we observed three distinct response patterns: driven by stable species, transient species, and both together in response to the six factors. We identified 273 potential biomarkers (200 robust core species and 73 robust differential species). Six genera and eight species of pathogens were detected in ticks, with an overall positivity rate of 12.44% (96/772). Among humans, 18.27% (38/208) of serum samples were positive for at least one tick-borne pathogen IgG. Our findings indicate that these six factors significantly influence both tick microbial communities and vectorial capacity, with varying effects on vector competence for different pathogens and inconsistent impacts on microbial communities under different conditions. This study supplemented the understanding of tick microbial communities on Hainan Island, assessed the relatively high risk of tick-borne pathogens in the region, and evaluated the impact of these factors on both microbial communities and vectorial capacity.

Estimated incidence of symptomatic Lyme borreliosis cases in five southern coastal counties in Norway, 2022.

Lyme borreliosis (LB), the most common tick-borne disease in Europe, is endemic to southern coastal Norway. LB commonly presents as erythema migrans, which can disseminate, resulting in more severe disease such as Lyme neuroborreliosis or arthritis. In Norway, public health LB surveillance is conducted via mandatory reporting of laboratory-confirmed disseminated cases. From 2012 to 2022, Norway's surveillance-reported incidence of laboratory-confirmed disseminated LB increased by 78%. Although surveillance provides estimates of the incidence of disseminated LB, this study sought to estimate the incidence of symptomatic LB to better understand Norway's LB disease burden. Two studies were identified that, when combined, estimated an LB seroprevalence of 6.8% in the general adult population in southern Norway. Utilizing data from these seroprevalence studies, public health surveillance, and results from literature searches indicating that 37% of seroconverted LB cases are symptomatic and that the duration of LB antibody detection ranges from 10 to 20 years, we estimated that there were 315-630 symptomatic LB cases per 100,000 adult population in five southern coastal counties in Norway in 2022 and 24-48 cases of symptomatic LB for every public health surveillance-reported LB case in adults in these five counties in Norway.

Clinical Findings, Laboratory Results, Electrocardiography and Echocardiography Findings in Dairy Buffaloes with Theileriosis.

Tropical theileriosis is a tick-borne haemoprotozoan disease, and cardiac function assessment in buffaloes with theileriosis was poorly documented. The Present study was carried out from April 2022 to December 2022. Theileriosis was confirmed by microscopic examination of stained blood smears and lymphnode smearsfurther confirmed by PCR assay. Electrocardiography was performed byusing the base apex lead system, and echocardiography was performed byusing the right parasternal view. The incidence of theileriosis was 16.25% by examination of stained blood smears, and 30.42% by PCR examination in 240 buffaloes. Repeatedly noted clinical signs were the absence of rumination, anorexia, loss of milk yield, depressed demeanour, emaciation, hyperthermia, lymphadenopathy, tick infestation, tachycardia, cardiac arrhythmia, and increased intensity of heartbeat. Haematological findings disclosed decreased haemoglobin, packed cell volume, total erythrocyte count, and neutrophils; increased eosinophils and monocytes. Serum biochemical findings revealed decreased albumin, albumin/globulin ratio, glucose, calcium, phosphorous, sodium, potassium, and chloride; increased globulin, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatinine, cholesterol, lactate dehydrogenase, gamma-glutamyl transferase, and creatine kinase myocardial band isoenzymes. Electrocardiography explorations were sinus tachycardia, broad T wave, and sinus arrhythmia. Echocardiography examination showed ventricular wall thickening, cardiac chamber dilatation, valvular defects/valvular regurgitation, and pericarditis/cardiac tamponade. The present research proposes the changes in the electrocardiography and echocardiography findings in buffaloes with theileriosis, which are essential in clinics to identify the secondary complications during theileriosis and formulate therapeutics.

7045 A Rare Case of Lyme-Associated Thyroiditis in an Otherwise Healthy Patient

Abstract Disclosure: M. Windham: None. S.K. Majumdar: None. Introduction: Lyme disease, a common tick-borne illness, causes multiorgan inflammation and dysfunction. It commonly affects the musculoskeletal, neurologic, cardiovascular, and integumentary systems. The endocrine system is rarely involved. We report a case of Lyme-associated thyroiditis in an otherwise healthy 41-year-old man. Case: A 41-year-old man with a history of hypertension, gastroesophageal reflux and a known BRCA2 mutation presented to the emergency department due to one week of frequent palpitations, fatigue, dyspnea on exertion, and dry cough. Laboratory testing revealed thyrotoxicosis with an undetectable TSH (n 0.270—4.200 µIU/mL), FT4 of 7.04 ng/dL (n 0.80—1.70 ng/dL), and TT3 of 253 ng/dL (n 92.0—224 ng/dL). He denied any recent illnesses or pain in his thyroid. Further work up revealed negative TSI and TPO but did show an elevated high sensitivity CRP of 4.3 mg/L (n &amp;lt;1.0 mg/L) and a sedimentation rate of 33 mm/hr (n 0—20 mm/hr). A thyroid uptake and scan showed markedly decreased uptake suggestive of thyroiditis. The patient was started on a prednisone taper with improvement in his TFTs. At his follow up visit approximately one month later, he reported increasing stiffness in his bilateral jaw and continuing palpitations with movement despite near normalization in his FT4 and TT3, suggestive of possible underlying cardiac conduction defects. He did not recall a tick bite but lived in an area with endemic Lyme disease. Lyme antibodies were sent and returned with a positive Lyme IgG and an indeterminate Lyme IgM, which would be consistent with an active Lyme disease infection at the time of his initial presentation. Treatment for Lyme disease was prescribed. Conclusion: Between 1991 and 2021, the incidence of Lyme disease in the United States doubled due to the combined effects of climate change, increasing host species populations, and human encroachment on animal habitats. People who live in areas with endemic Lyme disease, such as the Northeast and upper Midwest regions of the United States, are at risk even if they do not recall a specific exposure. Although Lyme thyroiditis is extremely rare, its incidence is expected to increase as the overall incidence of Lyme disease increases. Therefore, it is important to consider Lyme disease in the differential when a patient from an endemic area presents with unexplained thyroiditis. Presentation: 6/2/2024

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.

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.

Severe fever with thrombocytopenia syndrome (SFTS) in Thailand: using a one health approach to respond to novel zoonosis and its implications in clinical practice

Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne disease caused by Dabie bandavirus (SFTSV) is an emerging infectious disease of substantial concern in East Asia. In 2019, Ongkittikul S et al. reported the first case of SFTS in Thailand. Our report describes a One Health investigation of SFTS zoonosis examining the index case and suspected animal reservoirs using real-time RT-PCR and immunoassays. We add to the report on the first confirmed case of SFTSV infection in a human in Thailand by conducting a limited but informative One Health surveillance study. Dogs and cats tested positive for SFTSV antibody using IgG ELISA. We conclude that domestic dogs and cats might serve as potential reservoirs for SFTSV spread due to their closer proximity to the index case than other non-domestic animals. Notably, we did not detect SFTSV in synanthropic cats or dogs—nor did we detect SFTSV in Rhipicephalus sanguineus ticks—using RT-PCR. We propose that One Health investigations coupling genomic and serologic assays in response to new SFTS cases could play a pivotal role in preventing and managing SFTS among humans and animals in East Asia. As such, we are establishing a collaborative response to SFTS in Thailand through human outbreak investigations that align with principles of One Health, through environmental surveys and animal RT-PCR and immunoassays. Our investigation highlights the importance of coupling RT-PCR with seroprevalence assays as principal elements of One Health surveillance for SFTS in order to shed light on potential animal reservoirs and track emerging zoonosis.

Molecular investigation of Coxiella burnetii, Brucella spp., Ehrlichia spp., and Borrelia spp. among patients suspected of having Crimean-Congo Hemorrhagic Fever in Iran

ObjectivesCrimean-Congo Hemorrhagic Fever (CCHF) is a tick-borne zoonotic viral disease that could be a public health concern. The overlapping of clinical symptoms of some acute bacterial febrile diseases with CCHF is of importance for clinical diagnosis. This study aimed to molecularly examination of Brucella, Coxiella burnetii, Borrelia, and Ehrlichia infections among individuals suspected of CCHF in Iran. MethodsIn this study, 260 serum samples of suspected cases of CCHF with definitively negative laboratory test results for CCHF virus infection, were examined for Brucella spp., Coxiella burnetii, Borrelia spp., and Ehrlichia spp. by Real-time PCR. ResultsAccording to the results, 3.46% and 3.07% of the patients were positive for brucellosis and Q fever, respectively. Notably, no cases of borreliosis or ehrlichiosis were detected. Among the positive cases for brucellosis (N= 9), three cases were identified as Brucella abortus infection. Individuals under the age of 43 displayed a significantly higher positivity rate for Q fever (p < 0.01). Furthermore, patients presenting with chills had a 5.81-fold increased likelihood of being infected with Q fever (95% CI: 1.39–24.26) compared to those without chills. Notably, no other variables demonstrated a statistically significant association with Q fever infection. Discussion and ConclusionsThe results of this study showed that bacterial infections such as Q fever and brucellosis should be considered as differential diagnoses of CCHF. It is recommended that other bacterial infections that can cause early clinical symptoms similar to CCHF should also be taken into consideration in future studies and serological and molecular investigations of these infections should be tested on a wide scale.