Prevalence Of Lyme Disease Research Articles

Climate‐associated variation in the within‐season dynamics of juvenile ticks in California

AbstractChanging climate has driven shifts in species phenology, influencing a range of ecological interactions from plant–pollinator to consumer–resource. Phenological changes in host–parasite systems have implications for pathogen transmission dynamics. The seasonal timing, or phenology, of peak larval and nymphal tick abundance is an important driver of tick‐borne pathogen prevalence through its effect on cohort‐to‐cohort transmission. Tick phenology is tightly linked to climatic factors such as temperature and humidity. Thus, variation in climate within and across regions could lead to differences in phenological patterns. These differences may explain regional variation in tick‐borne pathogen prevalence of the Lyme disease‐causing Borrelia bacteria in vector populations in the United States. For example, one factor thought to contribute to high Lyme disease prevalence in ticks in the eastern United States is the asynchronous phenology of ticks there, where potentially infected nymphal ticks emerge earlier in the season than uninfected larval ticks. This allows the infected nymphal ticks to transmit the pathogen to hosts that are subsequently fed upon by the next generation of larval ticks. In contrast, in the western United States where Lyme disease prevalence is generally much lower, tick phenology is thought to be more synchronous with uninfected larvae emerging slightly before, or at the same time as, potentially infected nymphs, reducing horizontal transmission potential. Sampling larval and nymphal ticks, and their host‐feeding phenology, both across large spatial gradients and through time, is challenging, which hampers attempts to conduct detailed studies of phenology to link it with pathogen prevalence. In this study, we demonstrate through intensive within‐season sampling that the relative abundance and seasonality of larval and nymphal ticks are highly variable along a latitudinal gradient and likely reflect the variable climate in the far western United States with potential consequences for pathogen transmission. We find that feeding patterns were variable and synchronous feeding of juvenile ticks on key blood meal hosts was associated with mean temperature. By characterizing within‐season phenological patterns of the Lyme disease vector throughout a climatically heterogeneous region, we can begin to identify areas with high potential for tick‐borne disease risk and underlying mechanisms at a finer scale.

Novel recombinant vaccinia virus-vectored vaccine affords complete protection against homologous Borrelia burgdorferi infection in mice

ABSTRACT The rising prevalence of Lyme disease (LD) in North America and Europe has emerged as a pressing public health concern. Despite the availability of veterinary LD vaccines, no vaccine is currently available for human use. Outer surface protein C (OspC) found on the outer membrane of the causative agent, Borrelia burgdorferi, has been identified as a promising target for LD vaccine development due to its sustained expression during mammalian infection. However, the efficacy and immunological mechanisms of LD vaccines solely targeting OspC are not well characterized. In this study, we developed an attenuated Vaccinia virus (VV) vectored vaccine encoding type A OspC (VV-OspC-A). Two doses of the VV-OspC-A vaccine conferred complete protection against homologous B. burgdorferi challenge in mice. Furthermore, the candidate vaccine also prevented the development of carditis and lymph node hyperplasia associated with LD. When investigating the humoral immune response to vaccination, VV-OspC-A was found to induce a robust antibody response predominated by the IgG2a subtype, indicating a Th1-bias. Using a novel quantitative flow cytometry assay, we also determined that elicited antibodies were capable of inducing antibody-dependent cellular phagocytosis in vitro. Finally, we demonstrated that VV-OspC-A vaccination generated a strong antigen-specific CD4+ T-cell response characterized by the secretion of numerous cytokines upon stimulation of splenocytes with OspC peptides. This study suggests a promising avenue for LD vaccine development utilizing viral vectors targeting OspC and provides insights into the immunological mechanisms that confer protection against B. burgdorferi infection.

Analysis of Lyme infections among children hospitalised in the Provincial Specialist Children’s Hospital in Olsztyn in 2013–2018

Introduction and objective: Lyme disease is the most common chronic, infectious, multisystem, multiform disease. The region of Warmia and Mazury, as well as Podlasie, and the region of Lower Silesia are endemic areas for Lyme disease in our country. The aim of the study was to analyse the prevalence of Lyme disease among children from the Warmian-Masurian Voivodeship hospitalised in the Provincial Specialist Children’s Hospital in Olsztyn. Materials and methods: The study group consisted of 109 patients admitted to a hospital with Lyme disease diagnosis. The study used a retrospective method based on the analysis of the medical history of patients admitted to the hospital in the period from January 2013 to December 2018. Results: More than half of the cases (56.88%) were elective hospital admissions, while 43.12% were emergency admissions. The largest number of patients complained of headaches (68.81%). In about half of the patients (54.13%), the first symptoms of the disease appeared in less than 3 months. Conclusions: Among hospitalised patients diagnosed with Lyme disease, urban school age girls were significantly more likely to be affected. Most patients hospitalised due to Lyme disease denied a tick bite. The majority of patients hospitalised during the study period presented with non-specific symptoms of Lyme disease. The time between symptom onset and the diagnosis of Lyme disease was significantly shorter in children under 7 years of age. The time of hospitalisation of children under the age of 7 years was significantly shorter than in other age groups.

What Makes It Tick: Exploring the Mechanisms of Post-treatment Lyme Disease Syndrome.

Post-treatment Lyme disease syndrome (PTLDS), which may also be referred to incorrectly as "chronic Lyme disease," is defined by the Infectious Diseases Society of America (IDSA) as the presence of fatigue, pain, and/or cognitive complaints with the functional impact that persists for more than six months after completing treatment for Lyme disease (LD). These symptoms occur in 10%-20% of patients previously diagnosed with LD caused by the bacteria Borrelia burgdorferi and appropriately treated with a course of antibiotics. The symptoms of PTLDS can be easily overlooked or misdiagnosed as a psychiatric manifestation in geographic locations that rarely see LD. In contrast, geographic locations with a higher prevalence of LD may be more aware of PTLDS symptoms and have higher clinical suspicion leading to this diagnosis. The pathophysiology behind the persistent symptoms some people experience from a primary infection is still largely unknown. Some mechanisms that have been proposed include permanent tissue damage and inflammation, immune system dysfunction, autoimmune response, co-infection, and even persistent infection refractory to treatment. We propose that ongoing PTLDS symptoms seem to be related to an autoimmune response to the tissue damage and inflammation caused by the viable or nonviable spirochete pathogen. At this point, PTLDS is diagnosed clinically as no quantifiable methods are available from laboratory or tissue diagnostics as of 2024. Similar pathophysiological features of PTLDS are seen in diseases such as COVID-19 or chronic fatigue syndrome (CFS). More effective diagnostic approaches might include further studies looking at a possible connection in the genomes of individuals developing PTLDS, quantifiable biomarkers, common inflammatory markers/pathways, and careful histopathological studies of human tissues.

Prevalence of Lyme Disease and Relapsing Fever Borrelia spp. in Vectors, Animals, and Humans within a One Health Approach in Mediterranean Countries.

The genus Borrelia has been divided into Borreliella spp., which can cause Lyme Disease (LD), and Borrelia spp., which can cause Relapsing Fever (RF). The distribution of genus Borrelia has broadened due to factors such as climate change, alterations in land use, and enhanced human and animal mobility. Consequently, there is an increasing necessity for a One Health strategy to identify the key components in the Borrelia transmission cycle by monitoring the human-animal-environment interactions. The aim of this study is to summarize all accessible data to increase our understanding and provide a comprehensive overview of Borrelia distribution in the Mediterranean region. Databases including PubMed, Google Scholar, and Google were searched to determine the presence of Borreliella and Borrelia spp. in vectors, animals, and humans in countries around the Mediterranean Sea. A total of 3026 were identified and screened and after exclusion of papers that did not fulfill the including criteria, 429 were used. After examination of the available literature, it was revealed that various species associated with LD and RF are prevalent in vectors, animals, and humans in Mediterranean countries and should be monitored in order to effectively manage and prevent potential infections.

Racial and ethnic disparities in Lyme disease in the United States.

Lyme disease (LD), caused by the spirochete Borrelia burgdorferi, is the most common vector-borne disease in the United States. Although most surveillance-reported cases are in people who are White, data suggest worse outcomes among people from racial and ethnic minority groups. We conducted a systematic literature review to describe racial disparities in LD. We described the epidemiology of LD by race and ethnicity, including clinical presentation at diagnosis, and summarised the literature on knowledge, attitudes and practices related to LD and ticks by race and ethnicity. Overall, the incidence and prevalence of LD were 1.2-3.5 times higher in White persons than in persons who identified as Asian or Pacific Islander and 4.5-6.3 times higher in White persons than in persons who identified as Black. Across multiple studies, people from racial and ethnic minority groups were more likely than White people to have disseminated manifestations of LD, including neurological manifestations and arthritis, and less likely to have erythema migrans. People from racial and ethnic minority groups were also more likely to report disease onset in the fall and less likely to report disease onset in the summer. Possible reasons for these disparities include lack of recognition of the disease in people with darker skin tones, lack of knowledge of disease risk for some groups and differences in exposure risk. Taken together, these results reinforce that all people residing in high-incidence areas are at risk of LD, regardless of race or ethnicity. Future prevention measures should be broadly targeted to reach all at-risk populations.

ADVANCING LYME DISEASE PREVENTION THROUGH COMPUTER VISION: A ROBUST APPROACH FOR TICK IDENTIFICATION

Lyme is a disease that is caused by Borrelia burgdorferi, a bacterium that is spread by ticks. The prevalence of Lyme disease has made it a major public health problem. Immediate identification of the bacteria-carrying parasites is important in preventing the epidemic. This research suggests an alternative approach which uses computer vision to identify Lyme diseases related to ticks. A dataset containing images of ticks was used to create and train a Convolutional Neural Network (CNN) model. Preprocessing and augmentation were done on the dataset with split data into training and testing sets prior to boosting model generalization. The architecture of the CNN consists of convolutional, batch normalization and pooling layers followed by fully connected layers for classification. The Adam optimizer trains the model with a piecewise learning rate schedule. Test set evaluation shows promising results with high accuracy in categorizing tick pictures. Furthermore, this study calculates precision, recall and F1 score metrics which indicates strong performance from this model. A confusion matrix as well as visualization is also used to prove that model can distinguish between different tick classes. This computer vision approach provides a powerful tool for automatic tick recognition thus aiding in early detection as well as prevention of Lyme disease KEYWORDS; Image analysis, deep learning, tick identification, epidemiological surveillance, disease management, public health interventions, artificial intelligence, zoonotic diseases, tick-borne pathogens, predictive modeling.

Dilution Effect of the Refractory Lizard Host on the Transmission of the Lyme Disease Pathogen by Its Tick Vector in Northern California

A current model for Ixodes scapularis was revised and extended to represent the temperature dependent life cycle and host structure for Ixodes pacificus, the vector of the Lyme disease pathogen Borrelia burgdorferi in the Western United States. Parameters were adjusted to reflect data collected in Mendocino, CA. The hosts for I. pacificus include the Western Fence Lizard, which is not only an incompetent host for B. burgdorferi, but some studies claim that it eliminates it in ticks that feed on this lizard. The lizard host has been proposed as a reason for lower prevalence of Lyme disease in the West. This hypothesis was tested quantitatively by varying the number of lizard hosts. Model results suggest that the presence of refractory hosts produces a dilution effect for B. burgdorferi infection and is likely to be the reason for observed lower prevalence of Lyme disease in the Western United States.

TROPSA and TRE31 Gene Knockouts to Prevent the Transmission of Lyme Disease from Tick to Host: A Research Protocol

Introduction: Ixodes scapularis, the blacklegged tick, is responsible for the transmission of Lyme disease. Rising temperatures and shorter winter seasons, due to climate change, is resulting in the Northward expansion of tick range. This is correlated with the increasing prevalence of Lyme disease in Canada. This research protocol aims to address this issue by genetically mutating the blacklegged tick which is primarily responsible for the transmission of Borrelia burgdorferi, the bacterium that causes Lyme disease, in North America. The proposed mutation involves two gene knockouts: TROSPA and TRE31. The blacklegged tick mutant is predicted to be unable to transmit Lyme disease to the white-footed mouse, Peromyscus leucopus. Methods: Mutated ticks will feed on the blood of Lyme positive mice and later naïve mice. The rate of Lyme disease transmission from mutated ticks will be compared to transmission rates in positive and negative wild type control groups. The statistical significance of the difference between these groups’ transmission rates will be evaluated by Student’s t-test with Fisher’s protected least significant difference test. Results: Based on the results from literature testing each mutation independently, we predict our I. scapularis mutant, having both TROSPA and TRE31 gene knockouts, will be unable to transmit Lyme disease to the white-footed mouse. Discussion: Unsuccessful transmission of Lyme disease from mutated ticks indicates that the TROSPA and TRE31 knockouts are effective in preventing B. burgdorferi from completing its lifecycle within the tick. Based on the expected results, the combined gene-knockout model presents a novel method to hinder the transmission of Lyme disease more effectively than previously investigated single gene knockouts. Conclusion: This research protocol suggests a strategy to decrease the rate of Lyme disease amongst ticks, and thus humans. Future research could explore efficacies of knocking out other genes in combination with TROSPA or TRE31.

Influence of ecological and climatic conditions on the spread of Borrelia burgdorferi in domestic dogs in Ukraine

Lyme-borreliosis is a zoonotic, infectious disease that has a complex chain of transmission of the pathogen Borrelia burgdorferi sensu lato and includes the relationship between ixodid ticks, vertebrate hosts, humans and companion animals in the environment. The article shows general trends in the prevalence of canine Lyme-borreliosis in Ukraine depending on environmental, climatic and physiographic factors. The results of a comparative cartographic analysis of the prevalence of Lyme borreliosis among domestic dogs in Ukraine are presented by systematizing, mathematical and statistical processing of the data obtained by surveying veterinarians engaged in clinical veterinary practice. The paper includes generalized data on the clinical manifestations, methods of diagnosis and treatment of Lyme borreliosis in dogs. We determined the dependence of the prevalence of Lyme borreliosis in dogs on the types of physical and geographical territories – natural zones of Ukraine. Each of the natural zones differs in types of relief, climatic conditions, soil types, composition of fauna and flora, which affect the epizootic chain of Lyme disease. There is a clear correlation between the incidence of Lyme borreliosis in dogs and the types of natural areas. The highest incidence of Lyme borreliosis in dogs was observed in the forest-steppe zone and the zone of broad-leaved forests. A sharp decrease in the incidence of dogs was recorded in areas of mixed forests, the Ukrainian Carpathians and in the South of Ukraine in the steppe zone. The study also confirmed that the prevalence of Lyme disease among domestic dogs was influenced by the climatic factors, in particular: gross moisture of territories, average annual air temperature and soil temperature. In Ukraine, veterinarians in the vast majority of cases use serological diagnostic methods: immunochromatographic analysis, immunoenzymatic assay, and western blot, which are insufficient, since the presence of antibodies to the Lyme borreliosis pathogen is only a confirmation of the animal's contact with the antigen and may not indicate the presence of the disease in the clinical form. The generalized data on the use of antimicrobial drugs in the treatment of Lyme borreliosis in dogs indicate the predominant use of tetracycline antibiotics and cephalosporins. The majority of veterinarians reported symptoms of Lyme arthritis, somewhat fewer reported Lyme nephritis, neuroborreliosis, Lyme carditis and in rare cases, veterinarians observed erythema at the site of tick bite. About half of the veterinarians in Ukraine observed an increase in the incidence of Lyme disease in dogs, indicating a probable deterioration of the epizootic and epidemiological situation regarding Lyme borreliosis, especially in areas with favourable conditions for the circulation of Lyme borreliosis pathogens in natural and urban ecotopes. The results substantiate the need for the further study of the circulation of Borrelia burgdorferi sensu lato and their ability to cause disease in humans and animals, as well as the need to implement the principles of the One Health concept for the control and management of Lyme borreliosis.

Cat Ownership and Rural Residence Are Associated with Lyme Disease Prevalence in the Northeastern United States.

Lyme disease (LD) is the most common vector-borne disease in the USA. Beyond its tick-borne nature, however, risk factors for LD are poorly understood. We used an online questionnaire to compare LD patients and non-LD counterparts and elucidate factors associated with LD. We investigated demographic, lifestyle, and household characteristics and use of prevention measures. Associations with LD were modeled using logistic regression, and average marginal effects were estimated. In total, 185 active or past LD patients and 139 non-patients participated. The majority of respondents were white (95%) and female (65%). Controlling for age, sex, and type of residential area, pet ownership was associated with an 11.1% (p = 0.038) increase in the probability of LD. This effect was limited to cat owners (OR: 2.143, p = 0.007; dog owners, OR: 1.398, p = 0.221). Living in rural areas was associated with a 36% (p = 0.001) increase in the probability of LD compared to living in an urban area. Participants who reported knowing someone with Lyme Disease were more likely to wear insect repellant and perform tick checks. This study suggests opportunities for improved LD prevention, including advising cat owners of their increased risk. Although patterns in adoption of LD prevention methods remain poorly understood, concern about LD risk does motivate their use.

Spatial epidemiological analysis of Lyme disease in southern Ontario utilizing Google Trends searches

Lyme disease is of growing concern in Ontario with endemic areas increasing in size. Differential diagnosis of Lyme disease patients should include their exposure status assuming knowledge of high-risk areas. The goal of this study was a spatial analysis of Lyme disease in southern Ontario for the years 2015–2019 with a focus on the association between Lyme disease prevalence and Internet search frequencies recorded by Google Trends. A choropleth map visualized the raw prevalence of Lyme disease across the 28 public health units of southern Ontario. A disease cluster comprising five public health units was identified in eastern Ontario using the flexible scan statistic (standard morbidity ratio = 4.9, p = 0.01). Poisson regression modeling revealed an association between Lyme disease prevalence and the search term “Lyme disease” in Google Trends (p = 0.032). Lyme disease prevalence was correlated with Google Trend searches, with an increase in relative risk by a factor of 1.19 (CI95%: 1.03, 1.39) for every 1% increase in search activity. Knowledge of the existence and location of high-risk or exposure areas for Lyme disease is important to properly diagnose patients. Exploiting the association between Lyme disease and Internet search activity by the population at risk can also further disease surveillance.

Surveillance and Molecular Identification ofBorreliaSpecies in Ticks Collected at U.S. Army Garrison Humphreys, Republic of Korea, 2018–2019

Tick-borne pathogens are contributing factors for the increased incidence of vector-borne diseases throughout the world, including Lyme borreliosis, one of the most prevalent spirochetes belonging to the Borrelia burgdorferi sensu lato group. The present study focused on the detection of Borrelia species from hard ticks collected at U.S. Army Garrison Humphreys, Republic of Korea (ROK), using molecular and genotypic analyses. Tick-borne disease surveillance was conducted from January to December, 2018-2019. A total of 24,281 ticks (2 genera and 5 species) were collected from road-killed Korean Water deer (KWD) and by tick drag. Haemaphysalis longicornis (92.0%) was the most commonly collected species, followed by Haemaphysalis flava (4.9%), Ixodes nipponensis (3.1%), Haemaphysalis phasiana (0.07%), and Haemaphysalis japonica (<0.01%). The ospA gene sequences of Borrelia afzelii were detected in 12/529 pools of I. nipponensis. Three and one pools were positive for B. afzelii and Borrelia miyamotoi, respectively, using the 16s rRNA gene. None of the pools of Haemaphysalis ticks collected from KWD or by tick drag were positive for Borrelia species. I. nipponensis was collected throughout the year from KWD and from February to November by tick drag, suggesting that they were active throughout the year, and expanding the risk period for acquiring Lyme borreliosis and Borrelia relapsing fever in the ROK. This study assessed disease risk factors associated with the prevalence of Lyme disease in ticks collected from KWD and by tick drag using molecular analysis. These results provide an understanding and awareness into the prevalence and molecular characteristics of Borrelia species in the ROK.

A seroepidemiological investigation of Lyme disease in Qiongzhong County, Hainan Province in 2019-2020.

The incidence and prevalence of Lyme disease are expanding and rising, respectively, which constitutes a worldwide public health problem. The present study aimed to investigate the prevalence of Lyme disease (LD) in Qiongzhong County, Hainan, and to determine the LD infection level in the local population, so as to provide evidence for further local LD surveillance as well as effective prevention and treatment measures. A total of 252 serum samples were collected from cases with suspected LD in Qiongzhong County, including 159 and 93 cases with joint and neurological symptoms, respectively. The serum samples were preliminarily screened for LD antibodies by indirect immunofluorescent assay (IFA). Western Blot (WB) was used to confirm the diagnosis of IFA positive serum samples. Of the 252 serum samples, 39 tested positive by indirect immunofluorescence, translating to a positive rate of 15.48%. Of these 39 positive serum samples, western blot testing confirmed 28 to be positive for LD antibodies, representing a positive rate of 11.11%. LD spirochete infection was found in individuals of different ages, with the positive rate being highest among those aged ≤20 and ≥81 years old (22.22% in both groups). The positive rate of LD antibody detection in men was 16.89%, which was higher than the rate of 13.46% seen in women; however, the difference was not statistically significant. The positive rate of LD antibody detection using the 2-step testing method was 10.06% in patients with joint symptoms, which was slightly lower than the positive rate among individuals with neurological symptoms. Our results confirm the presence of LD among the population of Qiongzhong County, Hainan. LD surveillance should be carried out to actively prevent and treat LD in the locality. Local doctors should also consider the possibility of LD when diagnosing and treating patients with arthritis and neurological diseases.

Prevalence and prediction of Lyme disease in Hainan province.

Lyme disease (LD) is one of the most important vector-borne diseases worldwide. However, there is limited information on the prevalence and risk analysis using correlated factors in the tropical areas. A total of 1583 serum samples, collected from five hospitals of Hainan Province, were tested by immunofluorescence assay (IFA) and western blot (WB) analyses using anti-Borrelia burgdorferi antibodies. Then, we mapped the distribution of positive rate (by IFA) and the spread of confirmed Lyme patients (by WB). Using ArcGIS, we compiled host-vector-human interactions and correlated data as risk factor layers to predict LD risk in Hainan Province. There are three LD hotspots, designated hotspot I, which is located in central Hainan, hotspot II, which contains Sanya district, and hotspot III, which lies in the Haikou-Qiongshan area. The positive rate (16.67% by IFA) of LD in Qiongzhong, located in hotspot I, was higher than that in four other areas. Of confirmed cases of LD, 80.77% of patients (42/52) whose results had been confirmed by WB were in hotspots I and III. Hotspot II, with unknowed prevalence of LD, need to be paid more attention considering human-vector interaction. Wuzhi and Limu mountains might be the most important areas for the prevalence of LD, as the severe host-vector and human-vector interactions lead to a potential origin site for LD. Qiongzhong is the riskiest area and is located to the east of Wuzhi Mountain. In the Sanya and Haikou-Qiongshan area, intervening in the human-vector interaction would help control the prevalence of LD.

Modeling the Sensitivity of Blacklegged Ticks (Ixodes scapularis) to Temperature and Land Cover in the Northeastern United States.

The prevalence of Lyme disease and other tick-borne diseases is dramatically increasing across the United States. While the rapid rise in Lyme disease is clear, the causes of it are not. Modeling Ixodes scapularis Say (Acari: Ixodidae), the primary Lyme disease vector in the eastern United States, presents an opportunity to disentangle the drivers of increasing Lyme disease, including climate, land cover, and host populations. We improved upon a recently developed compartment model of ordinary differential equations that simulates I. scapularis growth, abundance, and infection with Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) by adding land cover effects on host populations, refining the representation of growth stages, and evaluating output against observed data. We then applied this model to analyze the sensitivity of simulated I. scapularis dynamics across temperature and land cover in the northeastern United States. Specifically, we ran an ensemble of 232 simulations with temperature from Hanover, New Hampshire and Storrs, Connecticut, and land cover from Hanover and Cardigan in New Hampshire, and Windsor and Danielson in Connecticut. Consistent with observations, simulations of I. scapularis abundance are sensitive to temperature, with the warmer Storrs climate significantly increasing the number of questing I. scapularis at all growth stages. While there is some variation in modeled populations of I. scapularis infected with B. burgdorferi among land cover distributions, our analysis of I. scapularis response to land cover is limited by a lack of observations describing host populations, the proportion of hosts competent to serve as B. burgdorferi reservoirs, and I. scapularis abundance.

A comparative evaluation of northern and southern Ixodes scapularis questing height and hiding behaviour in the USA.

Ticks display a distinct type of host-seeking behaviour called questing. It has been proposed that the questing behaviour of Ixodes scapularis explains the geographic variation in Lyme disease (LD) risk in the eastern USA because the northern population has been shown to quest more often than the southern population. The height at which questing occurs is variable and this study aimed to characterize questing height for I. scapularis. Ticks were collected from a northern and southern state (i.e. Maryland and Texas) and bioassays were conducted. We report that nymphs from Texas quested at lower heights compared to nymphs from Maryland. In addition, only Texas nymphs exhibited a behaviour we call 'hiding behaviour'. These results may reflect the different composition of hosts between these two areas as the south has a higher abundance of lizards. In contrast, there was no significant difference in questing height between Maryland adults and Texas adults which was to be expected since adults are feeding on white-tailed deer in both locations. If all southern I. scapularis nymphs are questing at lower heights, this might make them less likely to come into contact with humans and this may be contributing to the geographical difference in LD prevalence.

Lyme Disease Prevalence by ICD-10-CM Codes

Lyme Disease Prevalence by ICD-10-CM Codes

Seroprevalence of Lyme disease in southwest Asturias

IntroductionTo correctly interpret the serological markers of Lyme disease, it is very important to determine the region's infection rate. The aim of this study was to ascertain the prevalence of specific antibodies against Borrelia burgdorferi in a rural district in northern Spain. MethodsThe presence of IgG antibodies against B. burgdorferi was determined by qualitative enzyme immunoassay in the serum of 1432 people divided into 3 groups: 316 blood donors, 432 individuals who attended the hospital without infection and 684 for whom Lyme serology testing was specifically requested as part of a differential diagnosis. In the latter group, the presence or absence of an occupational risk factor was recorded. ResultsAntibodies against B. burgdorferi were detected in 189 individuals (13.2%), 16 (5.1%) in the blood donors group, 62 (14.4%) in subjects who attended hospital without infection and 111 (16.2%) in subjects in whom a differential diagnosis of Lyme disease was requested (p<0.0001). In subjects with an occupational risk factor, the prevalence was 23.5%, peaking at 45.8% in men over 65 years. ConclusionOur study showed a high prevalence of antibodies against B. burgdorferi and higher than that seen in other areas with similar characteristics in Spain. However, our results are similar to those published from other European regions. The prevalence in the blood donors group was lower than that observed in the other groups. Older age, the male gender and occupational risks were associated with a higher prevalence of Lyme disease.

Estimates for Lyme borreliosis infections based on models using sentinel canine and human seroprevalence data.

Two models were developed to estimate Lyme borreliosis (LB) cases. One was based on the seroprevalence of Borrelia infections in human samples. This model used corrections for false negative and false positive results from published test sensitivity and specificity measures. A second model based on Borrelia infections in sentinel dogs was used to quantify the prevalence of Lyme disease Borrelia infections in humans; the reference baseline for this model was human and canine infections in Germany. A comparison of the two models is shown and differences discussed. The relationships between incidence, prevalence and total infection burden for LB were derived from published data and these were used in both models to calculate annual incidence, prevalence and total LB infections. The modelling was conservative and based on medical insurance records coded for erythema migrans. Linear model growth rates were used in place of the commonly adopted exponential growth. The mean of the two models was used to create estimates for various countries and continents. Examples from the analyses for LB estimated for 2018 include: incidence – USA 473,000/year, Germany 471,000/year, France 434,000/year and UK 132,000/year; prevalence – USA 2.4 million, Germany 2.4 million, France 2.2 million and UK 667,000; total infections – USA 10.1 million, Germany 10.0 million, France 9.3 million and UK 2.8 million. Estimates for the world for 2018 are: incidence 12.3 million/year; prevalence 62.1 million; and total infection burden 262.0 million. These figures are far higher than officially published data and reflect not only the underestimation of diagnosed cases, which is acknowledged by health agencies, but also undiagnosed and misdiagnosed cases.