Multiple factors affecting Ixodes ricinus ticks and associated pathogens in European temperate ecosystems (northeastern France).

In Europe, the main vector of tick-borne zoonoses is Ixodes ricinus, which has three life stages. During their development cycle, ticks take three separate blood meals from a wide variety of vertebrate hosts, during which they can acquire and transmit human pathogens such as Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis. In this study conducted in Northeastern France, we studied the importance of soil type, land use, forest stand type, and temporal dynamics on the abundance of ticks and their associated pathogens. Negative binomial regression modeling of the results indicated that limestone-based soils were more favorable to ticks than sandstone-based soils. The highest tick abundance was observed in forests, particularly among coniferous and mixed stands. We identified an effect of habitat time dynamics in forests and in wetlands: recent forests and current wetlands supported more ticks than stable forests and former wetlands, respectively. We observed a close association between tick abundance and the abundance of Cervidae, Leporidae, and birds. The tick-borne pathogens responsible for Lyme borreliosis, anaplasmosis, and hard tick relapsing fever showed specific habitat preferences and associations with specific animal families. Machine learning algorithms identified soil related variables as the best predictors of tick and pathogen abundance.

Epidemiology of ticks submitted from human hosts in Alberta, Canada (2000-2019).

ABSTRACTThe geographic range and occurrence of tick species is dynamic. This has important public health implications due to important tick species that can transmit pathogens. This study presents a retrospective review of tick genera recovered from humans and submitted for identification in Alberta, Canada, over a 19-year period. The total number of ticks and proportion of genera were analyzed over time. Molecular testing for a number of pathogens associated with Ixodes scapularis and I. pacificus was conducted. A total of 2,358 ticks were submitted between 2000 and 2019, with 98.6% being acquired in Alberta. The number of ticks submitted increased significantly over time (p < 0.0001). Dermacentor ticks were the most abundant genus, followed by Ixodes and Amblyomma. There was a significant decrease in the proportion of Dermacentor ticks between 2013 and 2019 (p = 0.02), with a corresponding increase in the proportion of Ixodes ticks over the same time (p = 0.04). No statistically significant change in seasonality was identified. Borrelia burgdorferi was detected in 8/76 (10.5%; 95% CI 5.4-19.4%) of all I. scapularis and I. pacificus ticks submitted. This translated to a B. burgdorferi positivity of 0.35% (95% CI 0.15-0.68%) among all ticks received. Dermacentor species (especially D. andersoni) remains the most common tick feeding on humans in Alberta. Small numbers of vector species (including I. scapularis/pacificus) are encountered annually over widely separated geographic areas in the province. The risk of exposure to tick-borne pathogens (e.g. Lyme disease) in Alberta remains low.

Early Erythema Migrans: Do Not Count on Plasma Cells.

ABSTRACT: Three hundred thousand new cases of Lyme disease are diagnosed annually in the United States. The earliest manifestation of the disease, erythema migrans, occurs earlier than serologic conversion, and skin biopsies can be very helpful in suggesting the diagnosis. Histopathologic findings vary depending on where in the lesion the specimen is taken, but typically consist of a superficial and deep perivascular and interstitial lymphocytic infiltrate with eosinophils centrally and with histiocytes and plasma cells at the periphery. Rare cases with interstitial histiocytes and rare-to-sparse plasma cells exist. We present a 67-year-old man whose skin biopsy, taken on day 2 of his eruption, demonstrated a subtle perivascular and interstitial infiltrate of histiocytes without plasma cells. Dermatopathologists need to be aware of this pattern and consider the diagnosis of erythema migrans, despite negative initial serologic testing.

Borrelia burgdorferi and Borrelia miyamotoi in Atlantic Canadian wildlife.

Borrelia burgdorferi and Borrelia miyamotoi are tick-vectored zoonotic pathogens maintained in wildlife species. Tick populations are establishing in new areas globally in response to climate change and other factors. New Brunswick is a Canadian maritime province at the advancing front of tick population establishment and has seen increasing numbers of ticks carrying B. burgdorferi, and more recently B. miyamotoi. Further, it is part of a region of Atlantic Canada with wildlife species composition differing from much of continental North America and little information exists as to the presence and frequency of infection of Borrelia spp. in wildlife in this region. We used a citizen science approach to collect a wide range of animals including migratory birds, medium-sized mammals, and small mammals. In total we tested 339 animals representing 20 species for the presence of B. burgdorferi and B. miyamotoi. We have developed new nested PCR primers and a protocol with excellent specificity for detecting both of these Borrelia species, both single and double infections, in tissues and organs of various wildlife species. The positive animals were primarily small non-migratory mammals, approximately twice as many were infected with B. burgdorferi than B. miyamotoi and one animal was found infected with both. In addition to established reservoir species, the jumping mouse (Napaeozapus insignis) was found frequently infected; this species had the highest infection prevalence for both B. burgdorferi and B. miyamotoi and has not previously been identified as an important carrier for either Borrelia species. Comprehensive testing of tissues found that all instances of B. burgdorferi infection were limited to one tissue within the host, whereas two of the five B. miyamotoi infections were diffuse and found in multiple systems. In the one coinfected specimen, two fetuses were also recovered and found infected with B. miyamotoi. This presumptive transplacental transmission suggests that vertical transmission in mammals is possible. This finding implies that B. miyamotoi could rapidly spread into wildlife populations, as well as having potential human health implications.

Borrelia burgdorferi Co-Localizing with Amyloid Markers in Alzheimer's Disease Brain Tissues.

BACKGROUND: Infections by bacterial or viral agents have been hypothesized to influence the etiology of neurodegenerative diseases. OBJECTIVE: This study examined the potential presence of Borrelia burgdorferi spirochete, the causative agent of Lyme disease, in brain autopsy tissue of patients diagnosed with either Alzheimer's (AD) or Parkinson's diseases. METHODS: Brain tissue sections from patients with age-matched controls were evaluated for antigen and DNA presence of B. burgdorferi using various methods. Positive Borrelia structures were evaluated for co-localization with biofilm and AD markers such as amyloid and phospho-tau (p-Tau) using immunohistochemical methods. RESULTS: The results showed the presence of B. burgdorferi antigen and DNA in patients with AD pathology and among those, one of them was previously diagnosed with Lyme disease. Interestingly, a significant number of Borrelia-positive aggregates with a known biofilm marker, alginate, were found along with the spirochetal structures. Our immunohistochemical data also showed that Borrelia-positive aggregates co-localized with amyloid and phospho-tau markers. To further prove the potential relationship of B. burgdorferi and amyloids, we infected two mammalian cell lines with B. burgdorferi which resulted in a significant increase in the expression of amyloid-ß and p-Tau proteins in both cells lines post-infection. CONCLUSION: These results indicate that B. burgdorferi can be found in AD brain tissues, not just in spirochete but a known antibiotics resistant biofilm form, and its co-localized amyloid markers. In summary, this study provides evidence for a likely association between B. burgdorferi infections and biofilm formation, AD pathology, and chronic neurodegenerative diseases.

Seroprevalence of antibodies against Borrelia burgdorferi sensu lato in healthy blood donors in Romania: an update.

BACKGROUND: The Borrelia burgdorferi sensu lato (s.l.) genogroup is the causative agent responsible for Lyme borreliosis, a common tick-borne infectious disease in some temperate regions of the Northern Hemisphere. In humans, the clinical manifestations of Lyme borreliosis vary from dermatological infection to severe systemic manifestations. In Romania, data on the seroprevalence of Lyme borreliosis and associated risk factors are scarce and outdated, as the only seroprevalence study with a large dataset was published more than 20 years ago. Therefore, the aim of the present study was to evaluate the seroprevalence for Borrelia burgdorferi s.l. in healthy blood donors from six Romanian counties and identify the associated risk factors. METHODS: The study was conducted among 1200 healthy blood donors aged between 18 and 65 years during November 2019 and September 2020 from six counties in the northwestern and central parts of Romania. A two-tiered testing strategy was applied. Positive and equivocal immunoenzymatic test results for IgG and IgM antibodies were further confirmed by Western blot. RESULTS: Serum samples from 20% of the blood donors had positive or equivocal IgG and IgM ELISA index values. In total, 2.3% of the serum samples for IgG and 1.8% for IgM were positive by Western blot. The seroprevalence for both antibodies varied between 1.5% (Satu-Mare) and 6.5% (Bistrița-Nasaud) in the six counties investigated. The highest seroprevalence was observed in men (4.7%), in blood donors performing their professional activities outdoors (4.2%), and in those aged ≥ 56 years (8%). CONCLUSIONS: These findings confirm the presence of specific IgG and IgM antibodies to B. burgdorferi s.l. among healthy blood donors from Romania. Furthermore, potential risk factors, such as gender, age, and behavior, associated with the presence of positive B. burgdorferi s.l. antibodies among healthy blood donors were identified.

A Novel Approach to the Treatment and Prevention of Alzheimer's Disease Based on the Pathology and Microbiology.

Utilizing the pathology and microbiology found in tissue from patients with documented Alzheimer's disease (AD), the pathogenesis of this fateful disorder has been made clear. Borrelia burgdorferi and Treponema denticola spirochetes enter the brain, mostly via neuronal pathways and the entorhinal circulation. These organisms easily pass through the blood-brain barrier and have an affinity for neural tissue. Once in the brain, the spirochetes make intra- and extracellular biofilms, and it is the biofilms that create the pathology. Specifically, it is the intracellular biofilms that are ultimately responsible for neurofibrillary tangles and dendritic disintegration. The extracellular biofilms are responsible for the inflammation that initially is generated by the first responder, Toll-like receptor 2. The hypothesis that arises from this work is two-pronged: one is related to prevention; the other to treatment. Regarding prevention, it is very likely possible that AD could be prevented by periodic administration of penicillin (PCN), which would kill the spirochetes before they made biofilms; this would prevent the disease and would not allow any of the above deleterious changes generated by the biofilms to occur. As regards treatment, it may be possible to slow or prevent further decline in early AD by administration of PCN together with a biofilm disperser. The disperser would disrupt the biofilm coating and enable the PCN to kill the spirochetes. This protocol could be administered in a trial with the control arm utilizing the current treatment. The progress of the treatment could be evaluated by one of the current blood tests that is semi-quantitative. The specific protocols are listed.

First report of Borrelia burgdorferi sensu stricto detection in a commune genospecies in Apodemus agrarius in Gwangju, South Korea.

Lyme disease is a tick-borne infectious disease caused by the Borrelia burgdorferi sensu lato complex. However, the distribution of Borrelia genospecies and the tissue detection rate of Borrelia in wild rodents have rarely been investigated. Here, we studied 27 wild rodents (Apodemus agrarius) captured in October and November 2016 in Gwangju, South Korea, and performed nested polymerase chain reaction targeting pyrG and ospA to confirm Borrelia infection. Eight rodents (29.6%) tested positive for Borrelia infection. The heart showed the highest infection rate (7/27; 25.9%), followed by the spleen (4/27; 14.8%), kidney (2/27; 7.4%), and lungs (1/27; 3.7%). The B. afzelii infection rate was 25.9%, with the highest rate observed in the heart (7/27; 25.9%), followed by that in the kidney and spleen (both 2/27; 7.4%). B. garinii and B. burgdorferi sensu stricto were detected only in the spleen (1/27; 3.7%). This is the first report of B. burgdorferi sensu stricto infection in wild rodents in South Korea. The rodent hearts showed a high B. afzelii infection rate, whereas the rodent spleens showed high B. garinii and B. burgdorferi sensu stricto infection rates. Besides B. garinii and B. afzelii, B. burgdorferi sensu stricto may cause Lyme disease in South Korea.

Probing an Ixodes ricinus salivary gland yeast surface display with tick-exposed human sera to identify novel candidates for an anti-tick vaccine.

In Europe, Ixodes ricinus is the most important vector of human infectious diseases, most notably Lyme borreliosis and tick-borne encephalitis virus. Multiple non-natural hosts of I. ricinus have shown to develop immunity after repeated tick bites. Tick immunity has also been shown to impair B. burgdorferi transmission. Most interestingly, multiple tick bites reduced the likelihood of contracting Lyme borreliosis in humans. A vaccine that mimics tick immunity could therefore potentially prevent Lyme borreliosis in humans. A yeast surface display library (YSD) of nymphal I. ricinus salivary gland genes expressed at 24, 48 and 72 h into tick feeding was constructed and probed with antibodies from humans repeatedly bitten by ticks, identifying twelve immunoreactive tick salivary gland proteins (TSGPs). From these, three proteins were selected for vaccination studies. An exploratory vaccination study in cattle showed an anti-tick effect when all three antigens were combined. However, immunization of rabbits did not provide equivalent levels of protection. Our results show that YSD is a powerful tool to identify immunodominant antigens in humans exposed to tick bites, yet vaccination with the three selected TSGPs did not provide protection in the present form. Future efforts will focus on exploring the biological functions of these proteins, consider alternative systems for recombinant protein generation and vaccination platforms and assess the potential of the other identified immunogenic TSGPs.

The problem of Lyme borreliosis infections in urban and rural residents in Poland, based on National Health Fund data.

INTRODUCTION AND OBJECTIVE: Some fragmentary studies show that the incidence of Lyme borreliosis in Poland is increasing. It has been generally accepted that the most affected are forestry workers and farmers. The aim of the study is to compare the incidence of borreliosis in urban and rural residents in 2008-2016. MATERIAL AND METHODS: Databases on Lyme borreliosis from the National Health Fund and Central Statistical Office in Poland were analyzed. For each patient, ambulatory or discharged from every hospital, the diagnosis was compulsorily reported as encoded following the International Classification of Diseases. RESULTS: A steadily increasing number of patients with borreliosis in Poland was found, which doubled in 2008 - 2016. The incidence was similar in urban and rural residents. In all the provinces in Poland, an increase in incidence of borreliosis was observed, although there were big differences between them. The highest frequency of borreliosis was in Podlasie and Warmia-Masuria provinces. The lowest incidence of borreliosis was noticed in Wielkopolska province. In the most provinces the increase in the incidence of borreliosis was steady, except Warmia-Masuria, where it was very low in 2008, and soaring since 2011. The number of cases per year between 2008 - 2016 increased in both in males and females. CONCLUSIONS: The results suggest the need for higher awareness of the risk of Lyme borreliosis in urban residents, because the incidence of Lyme borreliosis is growing independently of the place of residence. Prompt measures to prevent tick bites and appropriate education are urgently needed.

Are other tick-borne infections overlooked in patients investigated for Lyme neuroborreliosis? A large retrospective study from South-eastern Sweden.

In Europe, the hard tick Ixodes ricinus is considered the most important vector of human zoonotic diseases. Human pathogenic agents spread by I. ricinus in Sweden include Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, Rickettsia helvetica, the recently described Neoehrlichia mikurensis, Borrelia miyamotoi, tick-borne encephalitis virus (TBEV), and Babesia spp. (Babesia microti, Babesia venatorum and Babesia divergens). Since these pathogens share the same vector, co-infections with more than one tick-borne pathogen may occur and thus complicate the diagnosis and clinical management of the patient due to possibly altered symptomatology. Borrelia burgdorferi s.l., TBEV and B. miyamotoi are well-known to cause infections of the central nervous system (CNS), whereas the abilities of other tick-borne pathogens to invade the CNS are largely unknown. The aim of this study was to investigate the presence and clinical impact of tick-borne pathogens other than B. burgdorferi s.l. in the cerebrospinal fluid (CSF) and serum samples of patients who were under investigation for Lyme neuroborreliosis (LNB) in a tick-endemic region of South-eastern Sweden. CSF and serum samples from 600 patients, recruited from the Regions of Östergötland County, Jönköping County and Kalmar County in South-eastern Sweden and investigated for LNB during the period of 2009-2013, were retrospectively collected for analysis. The samples were analysed by real-time PCR for the presence of nucleic acid from B. burgdorferi s.l., B. miyamotoi, A. phagocytophilum, Rickettsia spp., N. mikurensis, TBEV and Babesia spp. Serological analyses were conducted in CSF and serum samples for all patients regarding B. burgdorferi s.l., and for the patients with CSF mononuclear pleocytosis, analyses of antibodies to B. miyamotoi, A. phagocytophilum, spotted fever group (SFG) rickettsiae, TBEV and B. microti in serum were performed. The medical charts of all the patients with CSF mononuclear pleocytosis and patients with positive PCR findings were reviewed. Of the 600 patients, 55 (9%) presented with CSF mononuclear pleocytosis, 13 (2%) of whom had Borrelia-specific antibodies in the CSF. One patient was PCR-positive for N. mikurensis, and another one was PCR-positive for Borrelia spp. in serum. No pathogens were detected by PCR in the CSF samples. Four patients had serum antibodies to B. miyamotoi, four patients to A. phagocytophilum, five patients to SFG rickettsiae, and six patients to TBEV. One patient, with antibodies to SFG rickettsiae, had both clinical and laboratory signs suggestive of a current infection. Nine patients had serum antibodies to more than one pathogen, although none of these was assessed as a current co-infection. We can conclude from this study that tick-borne co-infections are uncommon in patients who are being investigated for suspected LNB in South-eastern Sweden, an area endemic for borreliosis and TBE.

Documentation of a false positive Lyme disease serologic test in a patient with untreated Babesia microti infection carries implications for accurately determining the frequency of Lyme disease coinfections.

Although many infections may potentially cause a false positive Borrelia burgdorferi antibody test, particularly for IgM antibody, babesiosis is not regarded as an infection that does this. A patient with untreated babesiosis is described here who developed transient IgM seropositivity for antibodies to B. burgdorferi. Thus, the diagnosis of Lyme disease coinfection in patients with active babesiosis, as in patients with human granulocytic anaplasmosis, is more convincingly accomplished if an objective clinical manifestation of Lyme disease is present, such as an erythema migrans skin lesion.

Monitoring the patterns of submission and presence of tick-borne pathogens in Ixodes scapularis collected from humans and companion animals in Ontario, Canada (2011-2017).

BACKGROUND: The universal nature of the human-companion animal relationship and their shared ticks and tick-borne pathogens offers an opportunity for improving public and veterinary health surveillance. With this in mind, we describe the spatiotemporal trends for blacklegged tick (Ixodes scapularis) submissions from humans and companion animals in Ontario, along with pathogen prevalence. METHODS: We tested tick samples submitted through passive surveillance (2011-2017) from humans and companion animals for Borrelia burgdorferi, Borrelia miyamotoi, Anaplasma phagocytophilum and Babesia microti. We describe pathogen prevalence in ticks from humans and from companion animals and constructed univariable Poisson and negative binomial regression models to explore the spatiotemporal relationship between the rates of tick submissions by host type. RESULTS: During the study, there were 17,230 blacklegged tick samples submitted from humans and 4375 from companion animals. Tick submission rates from companion animals were higher than expected in several public health units (PHUs) lacking established tick populations, potentially indicating newly emerging populations. Pathogen prevalence in ticks was higher in PHUs where established blacklegged tick populations exist. Borrelia burgdorferi prevalence was higher in ticks collected from humans (maximum likelihood estimate, MLE = 17.5%; 95% confidence interval, CI 16.97-18.09%) than from companion animals (9.9%, 95% CI 9.15-10.78%). There was no difference in pathogen prevalence in ticks by host type for the remaining pathogens, which were found in less than 1% of tested ticks. The most common co-infection B. burgdorferi + B. miyamotoi occurred in 0.11% of blacklegged ticks from humans and animals combined. Borrelia burgdorferi prevalence was higher in unengorged (21.9%, 95% CI 21.12-22.65%) than engorged ticks (10.0%, 95% CI 9.45-10.56%). There were no consistent and significant spatiotemporal relationships detected via regression models between the annual rates of submission of each host type. CONCLUSIONS: While B. burgdorferi has been present in blacklegged ticks in Ontario for several decades, other tick-borne pathogens are also present at low prevalence. Blacklegged tick and pathogen surveillance data can be used to monitor risk in human and companion animal populations, and efforts are under consideration to unite surveillance efforts for the different target populations.

Evaluation of 2 ELISAs to determine Borrelia burgdorferi seropositivity in horses over a 12-month period.

The blacklegged tick (Ixodes scapularis), which transmits Borrelia burgdorferi, the causative agent of Lyme disease, has undergone rapid range expansion in Ontario. In horses, Lyme disease remains an enigmatic disease, with limited understanding of the pathogenesis and many issues pertaining to selection and interpretation of laboratory tests. We evaluated B. burgdorferi seropositivity in naturally exposed horses over a 12-mo period and compared paired samples with 2 common serologic tests. Serum samples were collected in 2017, ~1 y after initial testing, from a cohort of 22 horses that were seropositive in a 2016 seroprevalence study. Samples were tested using a C6 ELISA and a multiplex ELISA targeting outer surface proteins A, C, and F. 1 y after initial testing, 14 of 22 (64%) horses remained seropositive; 7 (32%) were positive on the multiplex ELISA, 2 (9%) on C6 ELISA, and 5 (23%) on both tests. Repeatability was 100% for the C6 ELISA, and 95% for the multiplex ELISA, with no significant difference between paired sample multiplex titer values. Our results indicate strong intra-test reliability, although further investigation is required to determine the clinical significance of serologic testing.

Interactions between sympatric invasive European fire ants (Myrmica rubra) and blacklegged ticks (Ixodes scapularis).

The blacklegged tick (Ixodes scapularis) and the invasive European fire ant (Myrmica rubra) are both expanding throughout their sympatric range in coastal New England. Ixodes scapularis is the primary vector of the bacterium Borrelia burgdorferi, which is the causative agent of Lyme disease, and Mount Desert Island, Maine, home to Acadia National Park, currently is affected by a high Lyme disease burden. Ticks have many natural predators, including ants, although no previous studies have investigated interactions between these two species. To test the hypothesis that the presence of M. rubra alters I. scapularis abundance, we collected ticks by drag-sampling at eight ant-infested sites and eight uninfested control sites in Acadia National Park. We found that nymph density was significantly higher at ant-infested sites, while larval density was significantly higher at control sites. In addition, we conducted a laboratory bioassay to measure M. rubra aggression against I. scapularis larvae, nymphs, and adults and Dermacentor variabilis adults, and found that ant aggression was significantly higher against D. variabilis adults than I. scapularis adults. Our findings support the hypothesis that M. rubra has divergent effects across I. scapularis life stages, and we discuss possible ecological mechanisms, including optimal microclimate and predation, that could promote density of nymphs while inhibiting density of larvae.

One man, three tick-borne illnesses.

A 70-year-old man presented to the emergency department with fevers, ankle edema and nausea following a presumed insect bite on his ankle 1 month prior. On examination, he was febrile and had left leg pain with passive range of motion. Laboratory studies revealed anemia, thrombocytopenia, acute kidney injury and elevated aminotransaminases. Due to his recent travel to the Northeastern United States, he was suspected of having a possible tick-borne illness. Serologies were positive for Borrelia burgdorferi, Anaplasma phagocytophilum and Babesia microti, and the patient was diagnosed with Lyme disease, babesiosis and anaplasmosis. He was treated with doxycyline, atovaquone and azithromycin, leading to resolution of symptoms. While co-infection with Lyme disease is common, infection with three tickborne illnesses at one time is relatively rare.

Coinfection of Ixodes scapularis (Acari: Ixodidae) Nymphs With Babesia spp. (Piroplasmida: Babesiidae) and Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) in Wisconsin.

Borrelia burgdorferi, the spirochete that causes Lyme disease, is endemic and widespread in Wisconsin. Research in the northeastern United States has revealed a positive association between Babesia microti, the main pathogen that causes babesiosis in humans, and Bo. burgdorferi in humans and in ticks. This study was conducted to examine associations between the disease agents in the Upper midwestern United States. Ixodes scapularis Say nymphs (N = 2,858) collected between 2015 and 2017 from nine locations in Wisconsin were tested for Babesia spp. and Borrelia spp. using real-time PCR. Two species of Babesia were detected; Ba. microti and Babesia odocoilei (a parasite of members of the family Cervidae). Prevalence of infection at the nine locations ranged from 0 to 13% for Ba. microti, 11 to 31% for Bo. burgdorferi sensu stricto, and 5.7 to 26% for Ba. odocoilei. Coinfection of nymphs with Bo. burgdorferi and Ba. odocoilei was detected in eight of the nine locations and significant positive associations were observed in two of the eight locations. The prevalence of nymphal coinfection with both and Bo. burgdorferi and Ba. microti ranged from 0.81 to 6.5%. These two pathogens were significantly positively associated in one of the five locations where both pathogens were detected. In the other four locations, the observed prevalence of coinfection was higher than expected in all but one site-year. Clinics and healthcare providers should be aware of the association between Ba. microti and Bo. burgdorferi pathogens when treating patients who report tick bites.

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.

Molecular surveillance of tick-borne diseases affecting horses in Poland-Own observations.

The purpose of the study was to carry out the molecular surveillance of piroplasmosis, granulocytic anaplasmosis and lyme borreliosis in horses which originated from Poland and exhibited symptoms raising the suspicion of the aforementioned disease units. The presence of Theileria equi genetic material was detected in 37 out of 512 examined horses (7.2%), and Anaplasma phagocytophilum in 9 (1.8%). The DNA of Borrelia burgdorferi was found in 11 out of 204 examined horses (5.4%). The above-cited results indicate that the problem of tick-borne diseases affecting horses in Poland is not as significant as in other parts of Europe, however they have to be considered in differential diagnosis of the diseases with lethargy, fever, anaemia and thrombocytopenia.