MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF AMBLYOMMA SCUTATUM (ACARI: IXODIDAE) ACCIDENTALLY INTRODUCED IN ITALY.

Eight ticks were found in Comacchio (FE), Italy parasitizing a young black iguana (Ctenosaura similis) that had been accidentally transported in a commercial plant container from Costa Rica. Specimens were identified morphologically as Amblyomma scutatum and then confirmed by the barcoding of the mitochondrial cytochrome c oxidase subunit 1 gene. Amblyomma scutatum is a common tick known to infest reptiles in Central America, Mexico, and Venezuela, but not in Europe. In Italy, the possibility for this tick to become endemic is unlikely because of the absence of its principal hosts. Nevertheless, this finding confirms the high risk of introducing exotic species that is linked with global commerce and therefore the need for veterinary control of shipments.

Towards modelling tick-virus interactions using the weakly pathogenic Sindbis virus: Evidence that ticks are competent vectors.

Most tick-borne viruses (TBVs) are highly pathogenic and require high biosecurity, which severely limits their study. We found that Sindbis virus (SINV), predominantly transmitted by mosquitoes, can replicate in ticks and be subsequently transmitted, with the potential to serve as a model for studying tick-virus interactions. We found that both larval and nymphal stages of Rhipicephalus haemaphysaloides can be infected with SINV-wild-type (WT) when feeding on infected mice. SINV replicated in two species of ticks (R. haemaphysaloides and Hyalomma asiaticum) after infecting them by microinjection. Injection of ticks with SINV expressing enhanced Green Fluorescent Protein (eGFP) revealed that SINV-eGFP specifically aggregated in the tick midguts for replication. During blood-feeding, SINV-eGFP migrated from the midguts to the salivary glands and was transmitted to a new host. SINV infection caused changes in expression levels of tick genes related to immune responses, substance transport and metabolism, cell growth and death. SINV mainly induced autophagy during the early stage of infection; with increasing time of infection, the level of autophagy decreased, while the level of apoptosis increased. During the early stages of infection, the transcript levels of immune-related genes were significantly upregulated, and then decreased. In addition, SINV induced changes in the transcription levels of some functional genes that play important roles in the interactions between ticks and tick-borne pathogens. These results confirm that the SINV-based transmission model between ticks, viruses, and mammals can be widely used to unravel the interactions between ticks and viruses.

Tick-borne bacterial agents in Hyalomma asiaticum ticks from Xinjiang Uygur Autonomous Region, Northwest China.

BACKGROUND: Hyalomma ticks are widely distributed in semi-arid zones in Northwest China. They have been reported to harbor a large number of zoonotic pathogens. METHODS: In this study, a total of 334 Hyalomma asiaticum ticks infesting domestic animals were collected from four locations in Xinjiang, Northwest China, and the bacterial agents in them were investigated. RESULTS: A putative novel Borrelia species was identified in ticks from all four locations, with an overall positive rate of 6.59%. Rickettsia sibirica subsp. mongolitimonae, a human pathogen frequently reported in Europe, was detected for the second time in China. Two Ehrlichia species (Ehrlichia minasensis and Ehrlichia sp.) were identified. Furthermore, two Anaplasma species were characterized in this study: Candidatus Anaplasma camelii and Anaplasma sp. closely related to Candidatus Anaplasma boleense. It is the first report of Candidatus Anaplasma camelii in China. CONCLUSIONS: Six bacterial agents were reported in this study, many of which are possible or validated pathogens for humans and animals. The presence of these bacterial agents may suggest a potential risk for One Health in this area.

Evaluation of haematological parameters in haemolytic anaemia caused by tick-borne pathogens in grazing cattle.

BACKGROUND: No tick-borne pathogens (TBPs) causing haemolytic anaemia in cattle have been reported, except Theileria orientalis and complete blood count (CBC) profile is the only haematological parameter to determine the severity of regenerative haemolytic anaemia. OBJECTIVES: To identify the causative agents of TBP-induced haemolytic anaemia and determine haematological parameters that indicate haemolytic anaemia in grazing cattle. METHODS: Eighty-two Korean indigenous cattle (Hanwoo) were divided into two groups: grazing (n = 67) and indoor (n = 15) groups. CBC and serum biochemistry were performed. PCR was conducted using whole blood-extracted DNA to investigate the prevalence of TBPs. RESULTS: TBP-induced haemolytic anaemia was observed in the grazing group. In grazing cattle, co-infection (43.3%, 29/67) was most frequently detected, followed by T. orientalis (37.6%, 25/67) and Anaplasma phagocytophilum infections (1.5%, 1/67). In indoor cattle, only co-infection (20%, 3/15) was identified. Grazing cattle exhibited regenerative haemolytic anaemia with marked monocytosis, mild neutropenia, and thrombocytopenia. According to grazing frequency, the 1st-time grazing group had more severe anaemia than the 2nd-time grazing group. Elevations in indirect bilirubin and L-lactate due to haemolytic anaemia were identified, and correlations with the respective markers were determined in co-infected grazing cattle. CONCLUSIONS: Quantitative evaluation of haematocrit, mean corpuscular volume, and reticulocytes (markers of regenerative haemolytic anaemia in cattle) was performed for the first time. Our results show that, in addition to T. orientalis, A. phagocytophilum is strongly associated with anaemia. The correlation between haemolytic anaemia severity and haematological parameters (indirect bilirubin, reticulocytes, and L-lactate) was confirmed.

Species-level Microbiota of Biting Midges and Ticks from Poyang Lake.

Objective: The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area, namely, Qunlu Practice Base, Peach Blossom Garden, and Huangtong Animal Husbandry, and whether vectors carry any bacterial pathogens that may cause diseases to humans, to provide scientific basis for prospective pathogen discovery and disease prevention and control. Methods: Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit (OPU) analysis, we characterized the species-level microbial community structure of two important vector species, biting midges and ticks, including 33 arthropod samples comprising 3,885 individuals, collected around Poyang Lake. Results: A total of 662 OPUs were classified in biting midges, including 195 known species and 373 potentially new species, and 618 OPUs were classified in ticks, including 217 known species and 326 potentially new species. Surprisingly, OPUs with potentially pathogenicity were detected in both arthropod vectors, with 66 known species of biting midges reported to carry potential pathogens, including Asaia lannensis and Rickettsia bellii, compared to 50 in ticks, such as Acinetobacter lwoffii and Staphylococcus sciuri. We found that Proteobacteria was the most dominant group in both midges and ticks. Furthermore, the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria. Pantoea sp7 was predominant in biting midges, while Coxiella sp1 was enriched in ticks. Meanwhile, Coxiella spp., which may be essential for the survival of Haemaphysalis longicornis Neumann, were detected in all tick samples. The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors. Conclusion: Biting midges and ticks carry large numbers of known and potentially novel bacteria, and carry a wide range of potentially pathogenic bacteria, which may pose a risk of infection to humans and animals. The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.

Ticks - public health risks in urban green spaces.

BACKGROUND: Urban green spaces are important for human health, but they may expose visitors to tick-borne diseases. This not only presents a potential public health challenge but also undermines the expected public health gains from urban green spaces. The aim of this study is to assess the public health risk of tick-borne diseases in an urban green space used for recreation in Stockholm, Sweden. METHODS: We used a mixed method approach identifying both the magnitude of the tick hazard and the extent of the human exposure to tick-borne diseases. At six entry points to an urban green space, we sampled ticks and documented microhabitat conditions from five randomly assigned 2 m × 2 m plots. Surrounding habitat data was analyzed using geographical information system (GIS). Nymphs and adult ticks were tested for Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum using TaqMan qPCR. Positive B. burgdorferi (s.l.) ticks were further analyzed by nested PCR amplification and sequence analysis. Population census data and visitor count data were used to estimate the degree of human exposure to tick-borne diseases. To further understand the degree to which visitors get in contact with infected ticks we also conducted interviews with visitors to green spaces. RESULTS: High tick densities were commonly found in humid broadleaved forest with low field vegetation. High pathogen prevalence was significantly correlated with increasing proportions of artificial areas. Integrating the tick hazard with human exposure we found that the public health risk of tick-borne diseases was moderate to high at most of the studied entry points. Many of the visitors frequently used urban green spaces. Walking was the most common activity, but visitors also engaged in activities with higher risk for tick encounters. Individual protective measures were connected to specific recreational activities such as picking berries or mushrooms. CONCLUSIONS: The number of visitors can be combined with tick inventory data and molecular analyses of pathogen prevalence to make crude estimations of the public health risk of tick-borne diseases in urban green spaces. The risk of encountering infected ticks is omnipresent during recreational activities in urban green spaces, highlighting the need for public health campaigns to reduce the risk of tick-borne diseases.

Identification of a novel orthonairovirus from ticks and serological survey in animals near China-North korea border.

Emerging pathogenic tick-borne viruses (TBVs) have attracted a great deal of attention due to their significant impact on human and animal health. A novel orthonairovirus named Dadong virus (DDV) was isolated from Haemaphysalis concinna ticks in the Changbai Mountain region on the China-North Korea border. DDV can induce cytopathic effects in mammalian and human cell lines. Phylogenetic analysis showed that it belongs to the genus Orthonairovirus, family Nairoviridae, exhibiting 72.4%-81.3% nucleic acid identity to Tofla orthonairovirus, known to cause lethal infection in IFNAR KO mice. The first serological evidence of DDV circulating in cattle and mice was also obtained, with 4.0% (1/25) of cattle and 2.27% (1/44) of mice seropositive for DDV. Further investigations, including serological surveys using human samples, are required to assess the public health risk posed by DDV.

Subolesin knockdown in tick cells provides insights into vaccine protective mechanisms.

Ticks as obligate blood-feeding arthropod vectors of pathogenic viruses, bacteria, protozoa and helminths associated with prevalent tick-borne diseases (TBDs) worldwide. These arthropods constitute the second vector after mosquitoes that transmit pathogens to humans and the first vector in domestic animals. Vaccines constitute the safest and more effective approach to control tick infestations and TBDs, but research is needed to identify new antigens and improve vaccine formulations. The tick protein Subolesin (Sub) is a well-known vaccine protective antigen with a highly conserved sequence at both gene and protein levels in the Ixodidae and among arthropods and vertebrates. In this study, transcriptomics and proteomics analyses were conducted together with graph theory data analysis in wild type and Sub knockdown (KD) tick ISE6 cells in order to identify and characterize the functional implications of Sub in tick cells. The results support a key role for Sub in the regulation of gene expression in ticks and the relevance of this antigen in vaccine development against ticks and TBDs. Proteins with differential representation in response to Sub KD provide insights into vaccine protective mechanisms and candidate tick protective antigens.

Modeling Heartland virus disease in mice and therapeutic intervention with 4'-fluorouridine.

Heartland virus (HRTV) is an emerging tick-borne bandavirus that causes a febrile illness of varying severity in humans, with cases reported in eastern and midwestern regions of the United States. No vaccines or approved therapies are available to prevent or treat HRTV disease. Here, we describe the genetic changes, natural history of disease, and pathogenesis of a mouse-adapted HRTV (MA-HRTV) that is uniformly lethal in 7- to 8-week-old AG129 mice at low challenge doses. We used this model to assess the efficacy of the ribonucleoside analog, 4'-fluorouridine (EIDD-2749), and showed that once-daily oral treatment with 3 mg/kg of drug, initiated after the onset of disease, protects mice against lethal MA-HRTV challenge and reduces viral loads in blood and tissues. Our findings provide insights into HRTV virulence and pathogenesis and support further development of EIDD-2749 as a therapeutic intervention for HRTV disease. IMPORTANCE: More than 60 cases of HRTV disease spanning 14 states have been reported to the United States Centers for Disease Control and Prevention. The expanding range of the Lone Star tick that transmits HRTV, the growing population of at-risk persons living in geographic areas where the tick is abundant, and the lack of antiviral treatments or vaccines raise significant public health concerns. Here, we report the development of a new small-animal model of lethal HRTV disease to gain insight into HRTV pathogenesis and the application of this model for the preclinical development of a promising new antiviral drug candidate, EIDD-2749. Our findings shed light on how the virus causes disease and support the continued development of EIDD-2749 as a therapeutic for severe cases of HRTV infection.

Survey of ectoparasites affecting dog and cat populations living in sympatry in Gamo Zone, Southern Ethiopia.

BACKGROUND: Ectoparasites of dogs and cats are implicated to be responsible for life-threatening anaemia, allergic dermatitis and pruritic and non-pruritic skin disorders. In Ethiopia, few studies have been conducted on the arthropods of dogs and cats. OBJECTIVES: In order to shed light on some of these aspects, a survey was conducted to investigate the presence of ectoparasites in dogs and cats living in sympatry in the urban and rural areas of Gamo Zone, Ethiopia. METHODS: A total of 297 dogs and 110 cats were examined for ectoparasites, and questionnaires were employed to obtain information concerning owner's knowledge about arthropods and vector-borne diseases (VBDs). RESULTS: The overall prevalence of ticks, fleas and lice in dogs was 36.7%, 69.7% and 4.7%, respectively. Similarly, on cats, an overall prevalence of 2.7% ticks and 21.8% fleas was recorded. On dogs, fleas (Ctenocephalides felis 69.4%, Echidnophaga gallinacea 1.3%, Ctenocephalides canis 1.0% and Pulex irritans 0.3%), ticks (Amblyomma variegatum 22.9%, Rhipicephalus sanguineus 14.1%, Haemaphysalis leachi 8.8%, Rhipicephalus praetextatus 4.0% and Rhipicephalus pulchellus 3.4%) and lice (Heterodoxus spiniger 4.0% and Trichodectes canis 0.7%) were identified. Likewise, on cats, fleas (C. felis [15.5%] and E. gallinacea [7.3%]) and ticks (H. leachi [2.7%]) were identified. The abundance of C. felis was significantly higher (p < 0.001) on dogs, whereas in cats, the abundance of E. gallinacea was significantly higher (p = 0.002) than the other ectoparasites. On dogs, a significantly higher prevalence of Rh. sanguineus was recorded in urban areas (<0.001) and on dogs which live in indoor environments (p = 0.003) than on dogs which live in other environments. On the other hand, the prevalence of A. variegatum in rural areas and midland agroecology was significantly higher (p < 0.001). The prevalence of H. leachi was significantly higher in midland (p < 0.001) and on adult dogs (p = 0.001). Overall, fleas were more prevalent in rural (p = 0.029) than in urban areas, and female dogs were with higher infestation than the male (p = 0.047) dogs; C. felis was prevalent in female (p = 0.038) dogs than males. Overall, 88.3% owners in the study area had no knowledge about ectoparasites and VBDs of dogs and cats. Majority of the owners (64.8%) attest that they had never visited veterinary clinics. CONCLUSIONS: In conclusion, the data presented in the present study provide additional knowledge on the importance of ectoparasites of dogs and cats and are believed to contribute in awareness creation and strengthening of veterinary services of dogs and cats of the study area.

New insights into the molecular phylogeny, biogeographical history, and diversification of Amblyomma ticks (Acari: Ixodidae) based on mitogenomes and nuclear sequences.

BACKGROUND: Amblyomma is the third most diversified genus of Ixodidae that is distributed across the Indomalayan, Afrotropical, Australasian (IAA), Nearctic and Neotropical biogeographic ecoregions, reaching in the Neotropic its highest diversity. There have been hints in previously published phylogenetic trees from mitochondrial genome, nuclear rRNA, from combinations of both and morphology that the Australasian Amblyomma or the Australasian Amblyomma plus the Amblyomma species from the southern cone of South America, might be sister-group to the Amblyomma of the rest of the world. However, a stable phylogenetic framework of Amblyomma for a better understanding of the biogeographic patterns underpinning its diversification is lacking. METHODS: We used genomic techniques to sequence complete and nearly complete mitochondrial genomes -ca. 15 kbp- as well as the nuclear ribosomal cluster -ca. 8 kbp- for 17 Amblyomma ticks in order to study the phylogeny and biogeographic pattern of the genus Amblyomma, with particular emphasis on the Neotropical region. The new genomic information generated here together with genomic information available on 43 ticks (22 other Amblyomma species and 21 other hard ticks-as outgroup-) were used to perform probabilistic methods of phylogenetic and biogeographic inferences and time-tree estimation using biogeographic dates. RESULTS: In the present paper, we present the strongest evidence yet that Australasian Amblyomma may indeed be the sister-group to the Amblyomma of the rest of the world (species that occur mainly in the Neotropical and Afrotropical zoogeographic regions). Our results showed that all Amblyomma subgenera (Cernyomma, Anastosiella, Xiphiastor, Adenopleura, Aponomma and Dermiomma) are not monophyletic, except for Walkeriana and Amblyomma. Likewise, our best biogeographic scenario supports the origin of Amblyomma and its posterior diversification in the southern hemisphere at 47.8 and 36.8 Mya, respectively. This diversification could be associated with the end of the connection of Australasia and Neotropical ecoregions by the Antarctic land bridge. Also, the biogeographic analyses let us see the colonization patterns of some neotropical Amblyomma species to the Nearctic. CONCLUSIONS: We found strong evidence that the main theater of diversification of Amblyomma was the southern hemisphere, potentially driven by the Antarctic Bridge's intermittent connection in the late Eocene. In addition, the subgeneric classification of Amblyomma lacks evolutionary support. Future studies using denser taxonomic sampling may lead to new findings on the phylogenetic relationships and biogeographic history of Amblyomma genus.

The first cryptic genus of Ixodida, Cryptocroton n. gen. for Amblyomma papuanum Hirst, 1914: a tick of North Queensland, Australia, and Papua New Guinea.

We describe a new genus Cryptocroton n. gen. for Amblyomma papuanum Hirst, 1914, a tick of North Queensland, Australia, and Papua New Guinea.

Functional characterization of Francisella tularensis subspecies holarctica genotypes during tick cell and macrophage infections using a proteogenomic approach.

Tularemia is a vector-borne disease caused by the Gram-negative bacterium Francisella tularensis. Known hosts and vectors in Europe are hare and ticks. F. tularensis is transmitted from ticks and animals, but also from the hydrotelluric environment and the consumption of contaminated water or food. A changing climate expands the range in which ticks can live and consequently might contribute to increasing case numbers of tularemia. Two subspecies of F. tularensis are human pathogenic. Francisella tularensis tularensis (Ftt) is endemic in North America, while Francisella tularensis holarctica (Fth) is the only subspecies causing tularemia in Europe. Ft is classified as a category A bioterrorism agent due to its low infectious dose, multiple modes of transmission, high infectivity and potential for airborne transmission and has become a global public health concern. In line with the European survey and previous phylogenetic studies, Switzerland shows the co-distribution of B.6 and B.12 strains with different geographical distribution and prevalence within the country. To establish itself in different host environments of ticks and mammals, F. tularensis presumably undergoes substantial changes on the transcriptomics and proteomic level. Here we investigate the transcriptomic and proteomic differences of five strains of Fth upon infection of rabbit macrophages and tick cells.

Density and behavior of capybara (Hydrochoerus hydrochaeris) ticks (Acari: Ixodidae) Amblyomma sculptum and Amblyomma dubitatum with notes on Rickettsia bellii infection: Assessing human exposure risk.

In several urban and peri­urban areas of Brazil, populations of Amblyomma sculptum and Amblyomma dubitatum ticks are maintained by capybaras (Hydrochoerus hydrochaeris). In some of these areas, this host and these tick species are associated with Brazilian spotted fever (BSF), a lethal human disease caused by the bacterium Rickettsia rickettsii. In this work, we evaluated the risk of human exposure to these tick species using four collection techniques to discern host-seeking behavior. The study was carried out in 10 urban sites inhabited by capybaras in Uberlândia, a BSF-free municipality in southeastern Brazil. Ticks were collected in areas of 400 m2 at each site and at three seasons. Within the same municipality, the distance and speed of A. sculptum nymphs moving towards the CO2 traps were evaluated. In a sample of ticks Rickettsia DNA was investigated. During the study period, 52,953 ticks were collected. Among these, 83.4 % were A. sculptum (1,523 adults, 10,545 nymphs and 32,104 larvae) and 16.6 % were A. dubitatum (464 adults, 2,153 nymphs and 6,164 larvae). An average annual questing tick density of 4.4/m² was observed, with the highest density recorded at one site in autumn (31.8/m²) and the lowest in summer at another site (0.03/m²). The visual search yielded the highest proportion of A. sculptum larvae, constituting 47 % of the total and 63.6 % of all A. sculptum larvae. In contrast, CO2 traps collected a greater proportion of nymphs and adults of A. sculptum ticks. In the case of A. dubitatum, the CO2 trap was the most efficient technique with 57.7 % of captures of this species, especially of nymphs (94.5 % of captures) and adults (97.8 % of captures). Ticks' ambush height on vegetation (9 to 77 cm), observed by visual search 30 times, yielded a total of 20,771 ticks. Of these, 28 (93 %) were A. sculptum ticks, with only two (7 %) identified as A. dubitatum ticks. Among A. sculptum ticks, the nymph was the most attracted stage to humans and larva in the case of A. dubitatum. Amblyomma sculptum adults and nymphs were significantly more attracted to humans than those of A. dubitatum, but A. dubitatum larvae were significantly more attracted than the same stage of A. sculptum. The maximum distance and speed of horizontal displacement for A. sculptum nymphs were five meters and 2.0 m/h, respectively. The only species of Rickettsia detected in ticks, exclusively in A. dubitatum, was R. bellii. Importantly, it was observed that the higher the proportion of A. sculptum in the community of ticks, the lower the rate of infection of A. dubitatum by R. bellii. In conclusion, host-seeking behavior differed between the two tick species, as well as between stages of the same species. A greater restriction of A. dubitatum ticks to the soil was observed, while larvae and nymphs of A. sculptum dispersed higher in the vegetation. The behavior presented by A. sculptum provides greater opportunities for contact with the hosts, while A. dubitatum depends more on an active search for a host, the hunter behavior. Taken together, these observations show that a human being crossing an area infested with A. sculptum and A. dubitatum ticks will have almost exclusive contact with A. sculptum larvae and/or nymphs. Humans in a stationary position (sitting, lying or immobile) are exposed to both tick species, but they are more attractive to adults and mainly nymphs of A. sculptum compared to the corresponding stages of the tick A. dubitatum. The negative effect of A. sculptum on A. dubitatum infection by R. bellii deserves further studies.

The structure and behavioral patterns of the human population affected by ixodid tick bites in Irkutsk Region, Eastern Siberia, Russia.

The bites of hard ticks are the major route of transmission of tick-borne infections to humans, causing thousands of cases of diseases worldwide. However, the characteristics of the human population that is exposed to tick bites are still understudied. This work is aimed at characterizing both the structure of the population directly contacting ticks and the human behavioral features associated with tick bites. We studied 25,970 individuals who sought medical help after a tick bite at the Centre for Diagnostics and Prevention of Tick-borne Infections (CDPTBI) in Irkutsk City (Russian Federation). The demographic and behavioral characteristics of the human population were analyzed using z-tests for proportions, the Mann-Whitney U test, and the Spearman rank correlation coefficient. The majority of bitten people were urban residents (70 %), and most of them were either of active ages between 30 and 74 years old (62 %), or children between 0 and 9 years old (approximately 20%). Tick bites occurred mostly in the range of 150 km around the location of the diagnostic facility (83 %). In comparison to the general population, significant differences were revealed in the representation of different age groups among bitten people. The population affected by tick bites included fewer men and women in the ages of 10-29 and over 75 years old than would be predicted based on the demographics of the general population. Vice versa, the proportions of people in the ages of 5-9 and 60-74 increased among bitten people. Among men, such activities (in order of occurrence) as "leisure and recreation", "visiting allotments", "foraging for forest food", and "fulfilling work duties" tend to be more associated with tick bites. Among women, tick bites occurred mainly during "visiting allotments", "leisure and recreation", "visiting cemeteries" and "contact with pets and plants at home". The overall vaccination rate was 12 %; however, significantly more men than women were vaccinated against tick-borne encephalitis (up to 20 % vs. approximately 7 % respectively). The structure of the tick bite - affected population suggests that it is age-specific human behavior that mainly determines the frequency of contact between people and ticks. However, in several age groups, especially among children from 5 to 9 and people aged 30-39 years old, gender-related factors could significantly change the exposure of people to tick bites.

Web search volume as a near-real-time complementary surveillance tool of tick-borne encephalitis (TBE) in Italy.

The Internet is an important gateway for accessing health-related information, and data generated through web queries have been increasingly used as a complementary source for monitoring and forecasting of infectious diseases and they may partially address the issue of underreporting. In this study, we assessed whether tick-borne encephalitis (TBE)-related Internet search volume may be useful as a complementary tool for TBE surveillance in Italy. Monthly Google Trends (GT) data for TBE-related information were extracted for the period between January 2017 and September 2022, corresponding to the available time series of TBE notifications in Italy. Time series modeling was performed by applying seasonal autoregressive integrated moving average (SARIMA) models with or without GT data. The search terms relative to tick bites reflected best the observed temporal distribution of TBE cases, showing a correlation coefficient of 0.81 (95 % CI: 0.71-0.88). Particularly, both the reported number of TBE cases and GT searches occurred mainly during the summer. The peak of disease notifications coincided with that of Google searches in 4 of 6 years. Once calibrated, SARIMA models with or without GT data were applied to a validation set. Retrospective forecast made by the model with GT data was associated with a lower prediction error and accurately predicted the peak timing. By contrast, the traditional SARIMA model underestimated the actual number of TBE notifications by 65 %. Timeliness, easy availability, low cost and transparency make monitoring of the TBE-related Internet search queries a promising addition to the traditional methods of TBE surveillance in Italy.

Prevalence and associated risk factors of ixodid tick species infesting cattle and sheep in Balochistan, Pakistan.

Tick infestation poses a serious threat to animal health, leading to significant losses in terms of vector-borne disease transmission, reduced live weight, lower quality hides, decreased milk production, and impaired reproduction in tropical and subtropical regions worldwide. This study aimed to determine the prevalence, seasonal variation, distribution pattern, and associated risk factors of Ixodid family tick species in the cattle and sheep population of three different districts in Balochistan, Pakistan. This study employed a convenient sampling method, collecting 4080 adult ticks from 816 cattle and sheep of various breeds, ages, and sexes. Specific morphological keys were used to identify the ticks up to the genus and species level. Among cattle, the highest prevalence was recorded for R. (B) annulatus (27.01%), followed by R. (B) microplus (24.02%), and H. anatolicum (20.54%). H. dromedarii (5.29%) was the least prevalent species observed in cattle. In the sheep population, H. anatolicum (30.34%) showed the highest prevalence, followed by H. marginatium (22.99%), and R. (B) annulatus (20.88%). H. dromedarii (6.96%) was the least prevalent species observed in sheep. The prevalence of R. (B) decoloratus, H. anatolicum and H. dromedarii was found to be significantly associated (P < 0.05) with the breed, age, and sex of both cattle and sheep. However, the presence of R. (B) annulatus, R. (B) microplus and H. marginatium tick species showed no significant association (P > 0.05) with these factors. In addition, the prevalence of ticks was higher in younger, female, and crossbred Friesian cattle compared to adults, males, and other breeds. Conversely, the prevalence of ticks was higher in adult, female and Hernai breed of sheep in the studied area. In conclusion, R. (B) annulatus and H. anatolicum are the dominant tick species infesting the cattle and sheep population in Balochistan. Consequently, this study provides valuable insights for developing practical and effective control measures against ticks and tick-borne diseases in the sheep and cattle population of Balochistan, Pakistan.

Ehrlichia effector TRP120 manipulates bacteremia to facilitate tick acquisition.

Ehrlichia species are obligatory intracellular bacteria that cause a potentially fatal disease, human ehrlichiosis. The biomolecular mechanisms of tick acquisition of Ehrlichia and transmission between ticks and mammals are poorly understood. Ehrlichia japonica infection of mice recapitulates the full spectrum of human ehrlichiosis. We compared the pathogenicity and host acquisition of wild-type E. japonica with an isogenic transposon mutant of E. japonica that lacks tandem repeat protein 120 (TRP120) (ΔTRP120). Both wild-type and ΔTRP120 E. japonica proliferated similarly in cultures of mammalian and tick cells. Upon inoculation into mice, both wild-type and ΔTRP120 E. japonica multiplied to high levels in various tissues, with similar clinical chemistry and hematologic changes, proinflammatory cytokine induction, and fatal disease. However, the blood levels of ΔTRP120 E. japonica were almost undetectable within 24 h, whereas the levels of the wild type increased exponentially. Greater than 90% of TRP120 was released from infected cells into the culture medium. Mouse blood monocytes exposed to native TRP120 from culture supernatants showed significantly reduced cell surface expression of the transmigration-related markers Ly6C and CD11b. Larval ticks attached to mice infected with either wild-type or ΔTRP120 E. japonica imbibed similar amounts of blood and subsequently molted to nymphs at similar rates. However, unlike wild-type E. japonica, the ΔTRP120 mutant was minimally acquired by larval ticks and subsequent molted nymphs and, thus, failed to transmit to naïve mice. Thus, TRP120 is required for bacteremia but not disease. These findings suggest a novel mechanism whereby an obligatory intracellular bacterium manipulates infected blood monocytes to sustain the tick-mammal transmission cycle. IMPORTANCE: Effective prevention of tick-borne diseases such as human ehrlichiosis requires an understanding of how disease-causing organisms are acquired. Ehrlichia species are intracellular bacteria that require infection of both mammals and ticks, involving cycles of transmission between them. Mouse models of ehrlichiosis and tick-mouse transmission can advance our fundamental understanding of the pathogenesis and prevention of ehrlichiosis. Herein, a mutant of Ehrlichia japonica was used to investigate the role of a single Ehrlichia factor, named tandem repeat protein 120 (TRP120), in infection of mammalian and tick cells in culture, infection and disease progression in mice, and tick acquisition of E. japonica from infected mice. Our results suggest that TRP120 is necessary only for Ehrlichia proliferation in circulating mouse blood and ongoing bacteremia to permit Ehrlichia acquisition by ticks. This study provides new insights into the importance of bacterial factors in regulating bacteremia, which may facilitate tick acquisition of pathogens.

Leading report of molecular prevalence of tick borne Anaplasma marginale and Theileria ovis in yaks (Bos grunniens) from Pakistan.

Domestic yak (Bos grunniens) is an economically important feature of the mountainous region of Gilgit-Baltistan in Pakistan where agriculture is restricted and yaks play multiple roles which includes being a source of milk, meat, hides, fuel and power. However little is known about the parasitic infections in Pakistani yaks. Aim of this research was to report the prevalence and genetic diversity of protozoa parasite (Theileria ovis, 18 S rDNA gene was targeted) and an obligate bacterium (Anaplasma marginale, msp-1 gene was amplified) in the blood that was sampled from 202 yaks collected from four districts in Gilgit-Baltistan during January 2023 till January 2024. Results revealed that 6/202 (3%) yaks were of Theileria ovis while 8/202 (4%) were Anaplasma marginale infected. Positive PCR products of both parasites were confirmed by DNA sequencing and their similarity with previously available pathogen sequences was determined by BLAST analysis. Phylogenetic tree indicated that isolates of both parasites displayed genetic. Anaplasma marginale infection varied with the sampling districts and Shigar district had the highest rate of bacterial infection. Cows were significantly more prone to Theileria ovis infection than bulls. Calf and hybrid yaks were more prone to Anaplasma marginale infection. In conclusion, this is the first report that yaks residing the Gilgit-Baltistan region in Pakistan are infected with Theileria ovis and Anaplasma marginale. Similar larger scales studies are recommended in various regions of Gilgit-Baltistan to document the infection rates of these parasites to formulate strategies that will lead to the effective control of these pathogens.

Adapting vector surveillance using Bayesian experimental design: An application to an ongoing tick monitoring program in the southeastern United States.

Maps of the distribution of medically-important ticks throughout the US remain lacking in spatial and temporal resolution in many areas, leading to holes in our understanding of where and when people are at risk of tick encounters, an important baseline for informing public health response. In this work, we demonstrate the use of Bayesian Experimental Design (BED) in planning spatiotemporal surveillance of disease vectors. We frame survey planning as an optimization problem with the objective of identifying a calendar of sampling locations that maximizes the expected information regarding some goal. Here we consider the goals of understanding associations between environmental factors and tick presence and minimizing uncertainty in high risk areas. We illustrate our proposed BED workflow using an ongoing tick surveillance study in South Carolina parks. Following a model comparison study based on two years of initial data, several techniques for finding optimal surveys were compared to random sampling. Two optimization algorithms found surveys better than all replications of random sampling, while a space-filling heuristic performed favorably as well. Further, optimal surveys of just 20 visits were more effective than repeating the schedule of 111 visits used in 2021. We conclude that BED shows promise as a flexible and rigorous means of survey design for vector control, and could help alleviate pressure on local agencies by limiting the resources necessary for accurate information on arthropod distributions. We have made the code for our BED workflow publicly available on Zenodo to help promote the application of these methods to future surveillance efforts.