Distribution Of Ticks Research Articles

County-level surveillance for the lone star tick, Amblyomma americanum, and its associated pathogen, Ehrlichia chaffeensis, in Kentucky

Kentucky experiences some of the highest incidence rates for ehrlichiosis nationwide. Ehrlichiosis is a bacterial infection caused primarily by the pathogen Ehrlichia chaffeensis and can be transmitted to humans through the bite of an infected tick, notably Amblyomma americanum. Amblyomma americanum, the lone star tick, is common to Kentucky and much of the southeast, but has expanded farther north in recent years. As an abundant and aggressive nondiscriminatory biter, this species is of major public health concern for transmission of pathogens to humans. As this vector's range expands, surveillance remains a necessary tool providing data that allows researchers to track this expansion over time. The historical information on tick distribution in Kentucky is variable with very little data on a statewide scale. From January 2019 to December 2020, we conducted surveillance for A. americanum in Kentucky through field collections and the establishment of a statewide tick submission program with the help of the Kentucky Department for Public Health and screened for E. chaffeensis on a county-level throughout the state. We collected 5,726 A. americanum ticks in 77 counties and detected E. chaffeensis in 32 counties. The minimum infection rate was 1.8%. With the expansion of A. americanum and increasing cases of tick-borne diseases, future surveillance is needed to monitor this important tick vector over time.

Minimal Rickettsial Infection Rates and Distribution of Ticks in Uganda: An Assessment of the Seasonal Effects and Relevance to Tick-Borne Disease Risk in East Africa.

Tick-borne diseases (TBDs) pose a significant risk to humans and represent one of the major factors influencing readiness within the United States' military worldwide. Additionally, ticks and TBDs constitute major animal health problems leading to economic losses at multiple levels affecting low- and middle-income countries the hardest. Tick control is frequently hampered by issues ranging from acaricide resistance to lack of data on tick distribution and infection rates. We conducted a cross-sectional study to assess tick species distribution, host use, and rickettsial pathogen infection rate of ticks in different areas of the Uganda Cattle Corridor. We identified 4,425 hard ticks (Ixodida: Ixodidae) comprised of seven species by morphological characters with 3,315 ticks collected from four locations during the dry season and 1,110 ticks from one location during the wet season. Rickettsial pathogen prevalence was assessed in ticks collected from two districts to determine the minimum infection rate compared across seasons, village location, and tick species. We found statistically significant differences in the abundance and distribution of tick species among districts in the dry season, host animal species, and the proportion of rickettsial positive pools between villages. Seasonality, village location, and tick species do not affect the minimum infection rate of rickettsial pathogens of ticks in Uganda, but village location affects the proportion of positive tick pools. These results indicate geographical and seasonal differences among pathogen-harboring ticks contributing to our understanding of the current distribution of ticks and TBDs in Uganda.

Mapping and monitoring tick (Acari, Ixodida) distribution, seasonality, and host associations in the United Kingdom between 2017 and 2020.

Tick-borne disease risk is intrinsically linked to the distribution of tick vector species. To assess risk and anticipate disease emergence, an understanding of tick distribution, host associations, and seasonality is needed. This can be achieved, to some extent, using passive surveillance supported by engagement with the public, animal health, and public health experts. The Tick Surveillance Scheme (TSS) collects data and maps tick distribution across the United Kingdom (UK). Between 2017 and 2020, 3720 tick records were received and 39 tick species were detected. Most records were acquired in the UK, with a subset associated with recent overseas travel. The dominant UK acquired species was Ixodes ricinus (Ixodida: Ixodidae, Linnaeus), the main vector of Lyme borreliosis. Records peaked during May and June, highlighting a key risk period for tick bites. Other key UK species were detected, including Dermacentor reticulatus (Ixodida: Ixodidae, Fabricius) and Haemaphysalis punctata (Ixodida: Ixodidae, Canestrini & Fanzago) as well as several rarer species that may present novel tick-borne disease risk to humans and other animals. Updated tick distribution maps highlight areas in the UK where tick exposure has occurred. There is evidence of increasing human tick exposure over time, including during the COVID-19 pandemic, but seasonal patterns remain unchanged.

The wild life of ticks: Using passive surveillance to determine the distribution and wildlife host range of ticks and the exotic Haemaphysalis longicornis, 2010–2021

BackgroundWe conducted a large-scale, passive regional survey of ticks associated with wildlife of the eastern United States. Our primary goals were to better assess the current geographical distribution of exotic Haemaphysalis longicornis and to identify potential wild mammalian and avian host species. However, this large-scale survey also provided valuable information regarding the distribution and host associations for many other important tick species that utilize wildlife as hosts.MethodsTicks were opportunistically collected by cooperating state and federal wildlife agencies. All ticks were placed in the supplied vials and host information was recorded, including host species, age, sex, examination date, location (at least county and state), and estimated tick burden. All ticks were identified to species using morphology, and suspect H. longicornis were confirmed through molecular techniques.ResultsIn total, 1940 hosts were examined from across 369 counties from 23 states in the eastern USA. From these submissions, 20,626 ticks were collected and identified belonging to 11 different species. Our passive surveillance efforts detected exotic H. longicornis from nine host species from eight states. Notably, some of the earliest detections of H. longicornis in the USA were collected from wildlife through this passive surveillance network. In addition, numerous new county reports were generated for Amblyomma americanum, Amblyomma maculatum, Dermacentor albipictus, Dermacentor variabilis, and Ixodes scapularis.ConclusionsThis study provided data on ticks collected from animals from 23 different states in the eastern USA between 2010 and 2021, with the primary goal of better characterizing the distribution and host associations of the exotic tick H. longicornis; however, new distribution data on tick species of veterinary or medical importance were also obtained. Collectively, our passive surveillance has detected numerous new county reports for H. longicornis as well as I. scapularis. Our study utilizing passive wildlife surveillance for ticks across the eastern USA is an effective method for surveying a diversity of wildlife host species, allowing us to better collect data on current tick distributions relevant to human and animal health.

Using next generation sequencing for molecular detection and differentiation of Anaplasma phagocytophilum variants from host seeking Ixodes scapularis ticks in the United States

Anaplasmosis is increasingly common in the United States, with cases being reported over an expanding geographic area. To monitor for changes in risk of human infection, the U.S. Centers for Disease Control and Prevention monitors the distribution and abundance of host-seeking vector ticks (Ixodes scapularis and Ixodes pacificus) and their infection with Anaplasma phagocytophilum. While several variants of A. phagocytophilum circulate in I. scapularis, only the human-active variant (Ap-ha) appears to be pathogenic in humans. Failure to differentiate between human and non-human variants may artificially inflate estimates of the risk of human infection. Efforts to differentiate the Ap-ha variant from the deer variant (Ap-V1) in ticks typically rely on traditional PCR assays coupled with sequencing of PCR products. However, laboratories are increasingly turning to Next Generation Sequencing (NGS) to increase testing efficiency, retain high sensitivity, and increase specificity compared with traditional PCR assays. We describe a new NGS assay with novel targets that accurately segregate the Ap-ha variant from other non-human variants and further identify unique clades within the human and non-human variants. Recognizing that not all investigators have access to NGS technology, we also developed a PCR assay based on one of the novel targets so that variants can be visualized using agarose gel electrophoresis without the need for subsequent sequencing. Such an assay may be used to improve estimates of human risk of developing anaplasmosis in North America.

Prevalence and Distribution of Hard Ticks and Their Associated Risk Factors in Sheep and Goats from Four Agro-Climatic Zones of Khyber Pakhtunkhwa (KPK), Pakistan.

: BackgroundHard ticks are blood-sucking ectoparasites infesting all types of domestic ruminants throughout the world and serve as vectors in the dissemination of a wide variety of pathogens. Sheep and goat farming is a vital economic source for resource-poor farming communities in the Khyber Pakhtunkhwa (KPK) province of Pakistan. Aim: The aim of present study is to study the epidemiological profile of ticks in various agro-climatic zones of KPK. Materials and Methods: A total of 1500 (882 sheep and 618 goats) of all age groups and sexes were examined for the presence of ticks belonging to six districts in four agro-climatic zones of KPK province, Pakistan. Non-probability sampling was undertaken based on animal hosts’ selection, collection of hard ticks, and epidemiological parameters. Ticks collected from sheep and goats were identified phenotypically using standard keys. Results: The results revealed that Rhipicephalus microplus (36.2%) was the predominant tick species followed by Hyalomma anatolicum (25.2%), Hyalomma trancatum (18.1%), Hyalomma aegyptium (11.3%), Hyalomma asiaticum (6.9%), and Haemephysalis bispinosa (2.4%). Different epidemiological parameters showed that weather, humidity, and host age negatively affect (p < 0.05) tick load while temperatures (Minimum and Maximum), sunshine (hrs), and precipitation positively affected (p < 0.05) tick load. Host sex only showed a positive association with tick load (p > 0.05). The highest value of tick diversity index (H) 0.36748 was noted for Hyalomma anatolicum as this tick species was commonly distributed in three agro-climatic zones except in the Suleiman Piedmont zone, while Haemaphysalis bispinosa has the lowest diversity index (0.0334) as it was only found in the Central Valley Plains zone of KPK. The Shannon diversity index of tick diversity was highest at Barikot while the lowest index value was at Kabal (2.407). Similarly, a higher Simpson’s diversity index was at Barikot (0.9554) and the lowest hard index was noted at Takht bai (2.874). The dominance index showed that the tick species were more dominant at Takht bai (0.1251), while the lowest dominance was at Barikot (0.04465). Conclusions: It has been concluded that tick diversity and distribution, abundance, reproduction, development, and survival depend on prevailing climatic conditions. The present study would not only help to identify the tick species but also facilitate in devising effective control measures to minimize the transmission pathogens in sheep and goats being reared in the various agro-climatic zones of KPK province, Pakistan.

Regional Scale Distribution of Tick is Associated with Wildlife Distribution on the Boso Peninsula, Central Japan

千葉県房総半島におけるマダニ類と野生動物の分布の関連性．マダニ類は， 野生動物を介して様々な人獣共通感染症の病原体を媒介する公衆衛生上重要な生物であり，その分布は宿主 である野生動物の個体数増加や分布拡大によって変化している可能性がある。しかし，マダニと宿主動物の 分布変化および感染被害の拡大との関係を広域スケールで追跡した研究事例は日本ではほとんどない。本研 究では，マダニ媒介性感染症「日本紅斑熱」の流行地域である千葉県房総半島において，紅斑熱群リケッチ アを媒介するマダニ類の分布を 2013 年から 2020 年に調査し，1988–1993 年時の調査結果と比較するととも に，日本紅斑熱の感染拡大状況との対応を調べた。その結果，ニホンジカ（Cervus nippon）やイノシシ（Sus scrofa）の拡大方向と同じように西側の富津市へ分布を拡大したツノチマダニ（Haemaphysalis cornigera）， ヒゲナガチマダニ（H. kitaokai），オオトゲチマダニ（H. megaspinosa）が確認された。一方，1988–1993 年時 とほとんど分布域が変わらなかったキチマダニ（H. flava）やフタトゲチマダニ（H. longicornis）も確認され た。どのマダニ種の分布域も，単独では，どの時点においても日本紅斑熱患者発生地域と完全に一致しなかっ た。房総半島では病原体リケッチアは複数のマダニ類によって媒介されている可能性がある。

Predicting the current and future risk of ticks on livestock farms in Britain using random forest models

The most abundant tick species in northern Europe, Ixodes ricinus, transmits a range of pathogens that cause disease in livestock. As I. ricinus distribution is influenced by climate, tick-borne disease risk is expected to change in the future. The aims of this work were to build a spatial model to predict current and future risk of ticks on livestock farms across Britain. Variables relating both to tick hazard and livestock exposure were included, to capture a niche which may be missed by broader scale models. A random forest machine learning model was used due to its ability to cope with correlated variables and interactions. Data on tick presence and absence on sheep and cattle farms was obtained from a retrospective questionnaire survey of 926 farmers. The ROC of the final model was 0.80. The model outputs matched observed patterns of tick distribution, with areas of highest tick risk in southwest and northwest England, Wales, and west Scotland. Overall, the probability of tick presence on livestock farms was predicted to increase by 5–7 % across Britain under future climate scenarios. The predicted increase is greater at higher altitudes and latitudes, further increasing the risk of tick-borne disease on farms in these areas.

VIRAL DETECTION IN TICKS AND THE LEVEL OF TICKS’ INFESTATIONS AMONGST SMALL RUMINANTS IN MAIDUGURI, BORNO STATE

Ticks were the first arthropods to be established as vectors of pathogens and are currently recognized, along with mosquitoes, as the main arthropod vectors of disease agents to humans and domestic animals globally due to increased incidences of tick-borne diseases (TBDs) the world over. They are responsible for the transmission of many viral diseases to humans and domestic animals. Therefore, ticks infection and infestation results in great economic losses to resource-poor farming communities, especially in tropical and subtropical regions, including Nigeria, where approximately 80% of the world’s cattle population is raised. The current study is aimed to study the distribution, composition and abundance of ticks in Maiduguri, Borno State. Adult ticks were collected from 350 freshly butchered small ruminants (sheep and goats) from three locations within Maiduguri metropolis namely:Kasuwa shanu, Bulumkutu, and Maiduguri Central Abattoir. These were identified using taxonomy identification keys in to three species, Rhipicephalus, Amblyomma and Hyalomma, using stereomicroscope for each of the locations. They were crushed using bullet blender after the addition of glass beads and centrifuged. The supernatant from the crushed samples was used for viral detection by inoculating it on to two cell lines, Baby Hamster Kidney (BHK) and African Monkey Kidney (Vero E6), and were observed for cytopathic effects daily for a period of ten (10) days. The results showed a high level of ticks’ infestation amongst small ruminants in the study locations. Kasuwan Shanu has the highest distribution of ticks amongst sheep, followed by Maiduguri Central Abattoir while Bulumkutu has the least. More also, Kasuwan Shanu has the highest distribution of ticks amongst goats, followed by Bulumkutu while Maiduguri Central Abbatoir has the least. The three species of ticks investigated were found to comprise of either male or female or both in the different locations, and either of the two sexes is involved in the infestation. The results also showed the presence of virus in some of the tick samples isolated from the small ruminants andinoculated on to the cell lines due to the observed cytopathic effects. It is concluded that there is high level of ticks’ infestation among small ruminants in Maiduguri metropolis and a threat of viral disease transmission to humans and other animals.

Surveillance of Rocky Mountain wood ticks (Dermacentor andersoni) and American dog ticks (Dermacentor variabilis) in Colorado

Ticks pose an emerging threat of infectious pathogen transmission in the United States in part due to expanding suitable habitat ranges in the wake of climate change. Active and passive tick surveillance can inform maps of tick distributions to warn the public of their risk of exposure to ticks. In Colorado, widespread active surveillance programs have difficulty due to the state's diverse terrain. However, combining multiple citizen science techniques can create a more accurate representation of tick distribution than any passive surveillance dataset alone. Our study uses county-level tick distribution data from Northern Arizona University, the Colorado Department of Public Health and the Environment, and veterinary surveillance in addition to literature data to assess the distribution of the Rocky Mountain wood tick, Dermacentor andersoni, and the American dog tick, Dermacentor variabilis. We found that D. andersoni for the most part inhabits counties at higher elevations than D. variabilis in Colorado.

Survival in the understorey: Testing direct and indirect effects of microclimatological changes on Ixodes ricinus

The distribution of ticks in the Ixodes ricinus species complex is partly driven by climate, with temperature and relative humidity affecting survival. These variables are driven by macroclimate, but vary locally due to microclimate buffering. This buffering has been suggested to be one of the driving forces behind variation in tick survival and density in time and space. In order to understand the role of the herb layer with respect to this variation, we deployed I. ricinus within an existing experimental setup studying the response of forest understorey to micrometeorological changes. This allowed for the analysis of both direct effects of warming on tick survival in controlled field conditions, as well as indirect effects through changes in herb layer biomass. Herb layer biomass estimates were observed to be higher in plots that had been experimentally warmed, with a trend towards higher survival in these warmed plots. This marginal increase in survival rate may be due to increased microclimate buffering. Comparing our results to literature implies that canopy and shrub layer vegetation have a larger effect on climate buffering, and therefore also on tick survival. Since the herb layer biomass is expected to increase due to global warming and increased frequency of disturbance-induced canopy gaps, survival in forested habitats may increase in the future. This would increase the difference in survival compared to that in open habitats.

Synopsis of the ticks of Algeria with new hosts and localities records

BackgroundTicks are obligate hematophagous arthropods with a world-wide distribution that are extremely important not only in terms of human and animal health but also economically. In Algeria, information on tick species is scarce.MethodsA systematic literature review was performed using online databases. The information extracted from the databases was was supplemented by information from an original study. Ticks were collected from various hosts and by flagging from January 2018 to December 2019.ResultsTo date, in Algeria a total of 36 valid tick species belonging to two families have been recorded: (1) family Argasidae, with three Argas species and nine Ornithodoros species recorded; and (ii) family Ixodidae, with one Dermacentor species, three Haemaphysalis species, 10 Hyalomma species, four Ixodes species and six Rhipicephalus species recorded. The geographical distribution for each species was determined and listed. Eight new tick-host associations were recorded: four for Ixodes inopinatus sensu Estrada-Peña et al. 2014, one for Rhipicephalus bursa, one for R. turanicus, one for Hyalomma marginatum and one for Hy. lusitanicum. To our best knowledge, this study is the first to report the presence of I. inopinatus sensu Estrada-Peña et al. 2014 in Algeria. We also report here for the first time all tick species (Argasidae and Ixodidae) known to be present in Algeria.ConclusionThis article represents a tool for students and scientists who work in the field of ticks and provides important new data on the distribution of ticks in Algeria.Graphical

Ehrlichia canis rapid spread and possible enzooty in northern South Australia and distribution of its vector Rhipicephalus linnaei.

Recent concerns have arisen in Australia regarding detections of the exotic bacterium Ehrlichia canis which has resulted in ehrlichiosis outbreaks. In Australia, it is spread by the tropical brown dog tick Rhipicephalus linnaei, formerly Rhipicephalus sanguineus sensu lato tropical lineage. Previously, the tick has been recorded in South Australia in the Coober Pedy and the Oodnadatta areas. This study, which includes historical specimens data held in historical Australian arthropod collections, along with 10 sampled remote communities, confirms the wide distribution range of this species within the State. E. canis was detected by PCR in the ticks. The percentage of dogs hosting PCR-positive ticks increased from 2.8% (95% confidence interval [CI]: 0.3 to 9.7) in November-December 2020 to 62.9% (95% CI: 44.9 to 78.5) end of February 2021, initially in two then in seven Anangu Pitjantjatjara Yankunytjatjara lands communities in the far northern regions of South Australia. Our results suggest a rapid spread of the pathogen. No evidence of E. canis was found in nine regional communities. The extended tropical brown dog tick distribution indicates a greater area where E. canis may occur and may require management to minimise the impacts of ehrlichiosis outbreaks. Without the implementation of effective detection and control programs, this extended distribution of R. linnaei is likely to result in the spread of the bacterium to other regions.

Epidemiology of Ticks and Tick-Borne Pathogens in Domestic Ruminants across Southern African Development Community (SADC) Region from 1980 until 2021: A Systematic Review and Meta-Analysis.

Ticks are hematophagous ectoparasites that are capable of infesting a wide range of mammals, including domestic animals, ruminants, wildlife, and humans across the world, and they transmit disease-causing pathogens. Numerous individual epidemiological studies have been conducted on the distribution and prevalence of ticks and tick-borne diseases (TBDs) in the Southern African Developing Community (SADC) region, but no effort has been undertaken to synchronize findings, which would be helpful in the implementation of consolidated tick control measures. With the aim of generating consolidated pooled prevalence estimates of ticks and TBDs in the SADC region, we performed a systematic review and meta-analysis of published articles using the PRISMA 2020 guidelines. A deep search was performed on five electronic databases, namely, PubMed, ScienceDirect, Google Scholar, AJOL, and Springer Link. Of the 347 articles identified, only 61 of the articles were eligible for inclusion. In total, 18,355 tick specimens were collected, belonging to the genera Amblyomma, Haemaphysalis, Hyalomma, and Rhipicephalus (including Boophilus) across several countries, including South Africa (n = 8), Tanzania (n = 3), Zambia (n = 2), Zimbabwe (n = 2), Madagascar (n = 2), Angola (n = 2), Mozambique (n = 1), and Comoros (n = 1). The overall pooled prevalence estimate (PPE) of TBPs in livestock was 52.2%, with the highest PPE in cattle [51.2%], followed by sheep [45.4%], and goats [29.9%]. For bacteria-like and rickettsial TBPs, Anaplasma marginale had the highest PPE of 45.9%, followed by A. centrale [14.7%], A. phagocytophilum [2.52%], and A. bovis [0.88%], whilst Ehrlichia ruminantium had a PPE of 4.2%. For piroplasmids, Babesia bigemina and B. bovis had PPEs of 20.8% and 20.3%, respectively. Theileria velifera had the highest PPE of 43.0%, followed by T. mutans [29.1%], T. parva [25.0%], and other Theileria spp. [14.06%]. Findings from this study suggest the need for a consolidated scientific approach in the investigation of ticks, TBPs, and TBDs in the whole SADC region, as most of the TBDs are transboundary and require a regional control strategy.

Risk of tick-borne pathogen spillover into urban yards in New York City

BackgroundThe incidence of tick-borne disease has increased dramatically in recent decades, with urban areas increasingly recognized as high-risk environments for exposure to infected ticks. Green spaces may play a key role in facilitating the invasion of ticks, hosts and pathogens into residential areas, particularly where they connect residential yards with larger natural areas (e.g. parks). However, the factors mediating tick distribution across heterogeneous urban landscapes remain poorly characterized.MethodsUsing generalized linear models in a multimodel inference framework, we determined the residential yard- and local landscape-level features associated with the presence of three tick species of current and growing public health importance in residential yards across Staten Island, a borough of New York City, in the state of New York, USA.ResultsThe amount and configuration of canopy cover immediately surrounding residential yards was found to strongly predict the presence of Ixodes scapularis and Amblyomma americanum, but not that of Haemaphysalis longicornis. Within yards, we found a protective effect of fencing against I. scapularis and A. americanum, but not against H. longicornis. For all species, the presence of log and brush piles strongly increased the odds of finding ticks in yards.ConclusionsThe results highlight a considerable risk of tick exposure in residential yards in Staten Island and identify both yard- and landscape-level features associated with their distribution. In particular, the significance of log and brush piles for all three species supports recommendations for yard management as a means of reducing contact with ticks.Graphical

Ticks (Acari: Ixodidae) and Associated Pathoge Collected From Domestic Animals and Vegetation in Stann Creek District, Southeastern Belize, Central America.

Data on the prevalence and distribution of ticks and tick-borne diseases in Belize are lacking. Ticks (n = 564) collected from dogs, horses, and vegetation in two villages in Stann Creek District in southeastern Belize in 2018, were molecularly identified and screened for tick-borne nonviral human pathogens. The identity of 417 ticks was molecularly confirmed by DNA barcoding as Rhipicephalus sanguineus (Latreille) (66.43%), Amblyomma ovale Koch (15.59%), Dermacentor nitens Neumann (11.51%), Amblyomma sp. ADB0528 (3.6%), and the remainder being small records (2.87%) of Amblyomma coelebs Neumann, Amblyomma imitator Kohls, Amblyomma tapirellum Dunn, Amblyomma auricularium Conil, and Amblyomma maculatum Koch. Individual tick extracts were screened for the presence of Rickettsia spp., Babesia spp., Babesia microti, Borrelia spp., Ehrlichia spp., and Anaplasma spp. using available conventional polymerase chain reaction (PCR) assays. Rickettsia parkeri strain Atlantic Rainforest was identified in five specimens of A. ovale, and one other unidentified tick, all collected from dogs. Another unidentified tick—also collected from a dog—tested positive for an undefined but previously detected Ehrlichia sp. With the exception of D. nitens, all eight other tick species identified in this study were collected on dogs, suggesting that dogs could be usefully employed as sentinel animals for tick surveillance in Belize.

Distribution Prediction of Hyalomma asiaticum (Acari: Ixodidae) in a Localized Region in Northwestern China

Hyalomma tick species are considered the competent vector tick species that carry and transmit Crimean-Congo hemorrhagic fever virus (CCHFV) to humans and animals. Hyalomma asiaticum is one of the major tick species widespread in the Xinjiang Uygur Autonomous Region (XUAR) of China. To determine the potential prevalence of H. asiaticum in XUAR, species distribution modeling was performed using MaxEnt algorithm assembled with bioclimatic variables and curated tick presence records. The results indicate that potential habitats of H. asiaticum mainly cover the northern and western XUAR. The suitable habitats included the west rim of the Taklimakan Desert, Turpan Basin, and Junggar Basin. The models show a mean area under the curve of 0.865 ± 0.068 for H. asiaticum based on 10-fold cross-validation. Despite limited tick presence records used in the study, this work describes the potential distribution and the association of important bioclimatic variables that are crucial for the survival of H. asiaticum in many arid areas in XUAR. The model could be helpful in tick distribution study and surveillance of CCHFV in the region.

Recreation reduces tick density through fine-scale risk effects on deer space-use

Altered interactions between pathogens, their hosts and vectors have potential consequences for human disease risk. Notably, tick-borne pathogens, many of which are associated with growing deer abundance, show global increasing prevalence and pose increasing challenges for disease prevention. Human activities can largely affect the patterns of deer space-use and can therefore be potential management tools to alleviate human-wildlife conflicts. Here, we tested how deer space-use patterns are influenced by human recreational activities, and how this in turn affects the spatial distribution of the sheep tick (Ixodes ricinus), a relevant disease vector of zoonoses such as Lyme borrelioses. We compared deer dropping and questing tick density on transects near (20 m) and further away from (100 m) forest trails that were either frequently used (open for recreation) or infrequently used (closed for recreation, but used by park managers). In contrast to infrequently used trails, deer dropping density was 31% lower near (20 m) than further away from (100 m) frequently used trails. Similarly, ticks were 62% less abundant near (20 m) frequently used trails compared to further away from (100 m) these trails, while this decline in tick numbers was only 14% near infrequently used trails. The avoidance by deer of areas close to human-used trails was thus associated with a similar reduction in questing tick density near these trails. As tick abundance generally correlates to pathogen prevalence, the use of trails for recreation may reduce tick-borne disease risk for humans on and near these trails. Our study reveals an unexplored effect of human activities on ecosystems and how this knowledge could be potentially used to mitigate zoonotic disease risk.

Identification and Distribution of Human-Biting Ticks in Northwestern Spain.

Simple SummaryWe conducted a tick surveillance study in northwestern Spain. Nymphs of Ixodes ricinus were the most frequently collected. Rhipicephalus bursa, Rhipicephalus sanguineus sensu lato (s.l.), Hyalomma marginatum, Hy. lusitanicum, Dermacentor marginatus, D. reticulatus and Haemaphysalis punctata were also found, with adults as the main stage. The number of collected Hyalomma spp. and R. bursa has been progressively increasing over time. Although bites occurred throughout the year, the highest number of incidents was reported from April to July. The distribution patterns of the tick species were different between the north and the south of the region, which was related to cases detected in humans of the pathogens they carried. Adult men were more likely to be bitten by ticks than women. Ticks were most frequently removed from adults from the lower limbs, while for children, they were mainly attached to the head. Epidemiological surveillance is essential given the increase in tick populations in recent years.Ticks transmit a wide diversity of pathogens to a great variety of hosts, including humans. We conducted a tick surveillance study in northwestern Spain between 2014 and 2019. Ticks were removed from people and identified. Tick numbers, species, development stages, the timeline, seasonal and geographical distribution and epidemiological characteristics of people bitten by ticks were studied. We collected ticks from 8143 people. Nymphs of I. ricinus were the most frequently collected. Rhipicephalus bursa, R. sanguineus s.l., Hy. marginatum, Hy. lusitanicum, D. marginatus, D. reticulatus and H. punctata were also found, with adults as the main stage. The number of collected Hyalomma spp. and R. bursa has been progressively increasing over time. Although bites occurred throughout the year, the highest number of incidents was reported from April to July. The distribution patterns of the tick species were different between the north and the south of the region, which was related to cases detected in humans of the pathogens they carried. Adult men were more likely to be bitten by ticks than women. Ticks were most frequently removed from adults from the lower limbs, while for children, they were mainly attached to the head. Epidemiological surveillance is essential given the increase in tick populations in recent years, mainly of species potentially carrying pathogens causing emerging diseases in Spain, such as Crimean–Congo hemorrhagic fever (CCFH).

Geographical distribution of hard ticks (Acari:Ixodidae) and tick-host associations in Benin, Burkina-Faso, Ivory-Coast and Togo

Knowledge of ticks and associated pathogens is crucial to assess the risk of exposure of humans and animals to pathogens. For this review, we collected relevant data from published articles and field collections to provide an update on the biodiversity of ticks, and tick-host associations in four countries of West Africa: Benin, Burkina-Faso, Ivory-Coast, and Togo. The literature review was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The search was limited to literature published from 1953 to 2021 in English and French sources. Out of 104 articles retrieved, only 41 studies met the eligibility criteria and were included in the review. The final database included a total of 53,619 adults, nymphs and larval ticks belonging to 24 species and five genera (Amblyomma, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus) that were collected from 23 different species of wild and domestic animals. This is the first record of Ixodes aulacodi and Rhipicephalus simpsoni in Benin, together with two new host records for A. latum. This checklist allows an update on tick-host associations and provides information on the diversity of ticks in West Africa.