Impaired humidity sensing reduces tick survival by preventing water homeostasis.

Off-host periods are critical for ticks, representing a period when environmental stress, particularly dehydration, can impact tick survival. To prevent dehydration, ticks must be able to detect and move into high humidity areas to allow for water vapor uptake. Ionotropic receptor 93a (Ir93a), which is highly expressed in the front forelegs (location of Haller s organ), increases expression following dehydration, suggesting a role in humidity detection.

Assessing the value and knowledge gains from an online tick identification and tick-borne disease management course for the Southeastern United States.

Background: Tick-borne diseases are a growing public health threat in the United States. Despite the prevalence and rising burden of tick-borne diseases, there are major gaps in baseline knowledge and surveillance efforts for tick vectors, even among vector control districts and public health agencies. To address this issue, an online tick training course (OTTC) was developed through the Southeastern Center of Excellence in Vector-Borne Diseases (SECOEVBD) to provide a comprehensive knowledge base on ticks, tick-borne diseases, and their management.

Release the hens: a study on the complexities of guinea fowl as tick control.

Established tick control strategies often involve methods that can be damaging to existing environmental conditions or natural host ecology. To find more environmentally friendly methods, biological controls, like predators of ticks, have been suggested. There are natural predators of ticks, but most are generalists and not expected to control tick populations.

Survival of adult Amblyomma americanum, Amblyomma maculatum, and Dermacentor variabilis (Acari: Ixodidae) in four habitats in southeastern Virginia.

Adult, unfed Amblyomma americanum (Linnaeus), Amblyomma maculatum Koch, and Dermacentor variabilis (Say) ticks were housed inside environmental containers in situ from May through August 2015. The environmental containers were placed in 4 habitats in southeastern Virginia, United States. Two of the habitats were located in low ground and were prone to flooding; the other two consisted of a drier landscape located in a more upland habitat.

Newer Surveillance Data Extends our Understanding of the Niche of (Rickettsiales: Rickettsiaceae) Infection of the American Dog Tick (Acari: Ixodidae) in the United States.

Understanding the geographic distribution of infections in is important for tick-borne disease management in the United States, as both a tick-borne agent of interest and a potential confounder in surveillance of other rickettsial diseases. Two previous studies modeled niche suitability for with and without , from 2002 to 2012, indicating that the niche overestimates the infected niche. This study updates these, adding data since 2012.

Estimating the distribution of , a potential key host in expanding rickettsial tick-borne disease risk.

Increasingly, geographic approaches to assessing the risk of tick-borne diseases are being used to inform public health decision-making and surveillance efforts. The distributions of key tick species of medical importance are often modeled as a function of environmental factors, using niche modeling approaches to capture habitat suitability. However, this is often disconnected from the potential distribution of key host species, which may play an important role in the actual transmission cycle and risk potential in expanding tick-borne disease risk.

Newer Surveillance Data Extends our Understanding of the Niche of (Rickettsiales: Rickettsiaceae) Infection of the American Dog Tick (Acari: Ixodidae) in the United States.

Background: Understanding the geographic distribution of infections in is important for tick-borne disease management in the United States, as both a tick-borne agent of interest and a potential confounder in surveillance of other rickettsial diseases. Two previous studies modeled niche suitability for with and without , from 2002-2012, indicating that the niche overestimates the infected niche. This study updates these, adding data since 2012.

Tick Species Composition, Collection Rates, and Phenology Provide Insights into Tick-Borne Disease Ecology in Virginia.

To better understand tick ecology in Virginia and the increasing Lyme disease incidence in western Virginia, a comparative phenological study was conducted in which monthly collections were performed at twelve sampling locations in southwestern Virginia (high Lyme disease incidence) and 18 equivalent sampling locations in southeastern Virginia (low Lyme disease incidence) for one year. In western Virginia, we also explored the effect of elevation on collection rates of Ixodes scapularis Say (Acari: Ixodidae) and Amblyomma americanum (L.) (Acari: Ixodidae).

Spatio-temporal modelling of tick life-stage count data with spatially varying coefficients.

There is a vast amount of geo-referenced data in many fields of study including ecological studies. Geo-referencing is usually by point referencing; that is, latitudes and longitudes or by areal referencing, which includes districts, counties, states, provinces and other administrative units. The availability of large geo-referenced datasets for modelling has necessitated the development and application of spatial statistical methods.

Orofacial Manifestations of Lyme Disease: A systematic review.

Orofacial manifestations of Lyme disease can affect head and neck anatomical structures that are frequently examined by dental professionals. The purpose of this systematic review was to examine the literature for types and frequencies of orofacial manifestations documented in populations in the United States (US) with Lyme disease. Four electronic databases (Dentistry and Oral Sciences, PubMed, Cinahl Plus, and Medline) were systematically searched during the summer of 2019 using keywords and MeSH terms to identify relevant studies.

Trends and Opportunities in Tick-Borne Disease Geography.

Tick-borne diseases are a growing problem in many parts of the world, and their surveillance and control touch on challenging issues in medical entomology, agricultural health, veterinary medicine, and biosecurity. Spatial approaches can be used to synthesize the data generated by integrative One Health surveillance systems, and help stakeholders, managers, and medical geographers understand the current and future distribution of risk. Here, we performed a systematic review of over 8,000 studies and identified a total of 303 scientific publications that map tick-borne diseases using data on vectors, pathogens, and hosts (including wildlife, livestock, and human cases).

Focus Stacking Images of Morphological Character States for Differentiating the Adults of Ixodes affinis and Ixodes scapularis (Acari: Ixodidae) in Areas of Sympatry.

Adult females and males of Ixodes affinis and Ixodes scapularis are illustrated by focus stacking image photography, and morphological character states are described that reliably differentiate the two species. In conjunction with other environmental cues, such as the questing phenology of adults, these characteristics will enable the rapid identification of adults of either sex along the southern Coastal Plain of the United States, where these species are sympatric.

Scoping review of distribution models for selected ticks and rickettsial group pathogens.

The rising prevalence of tick-borne diseases in humans in recent decades has called attention to the need for more information on geographic risk for public health planning. Species distribution models (SDMs) are an increasingly utilized method of constructing potential geographic ranges. There are many knowledge gaps in our understanding of risk of exposure to tick-borne pathogens, particularly for those in the rickettsial group.

Passerine birds as hosts for Ixodes ticks infected with Borrelia burgdorferi sensu stricto in southeastern Virginia.

The ecology of vector-borne diseases in a region can be attributed to vector-host interactions. In the United States, tick-borne pathogens are the cause of the highest number of reported vector-borne diseases. In the mid-Atlantic region of the eastern United States, tick-borne diseases such as Lyme disease, have increased in incidence, with tick-host-pathogen interactions considered a contributing factor to this increase.

Exploring the Niche of Rickettsia montanensis (Rickettsiales: Rickettsiaceae) Infection of the American Dog Tick (Acari: Ixodidae), Using Multiple Species Distribution Model Approaches.

The American dog tick, Dermacentor variabilis (Say) (Acari: Ixodidae), is a vector for several human disease-causing pathogens such as tularemia, Rocky Mountain spotted fever, and the understudied spotted fever group rickettsiae (SFGR) infection caused by Rickettsia montanensis. It is important for public health planning and intervention to understand the distribution of this tick and pathogen encounter risk. Risk is often described in terms of vector distribution, but greatest risk may be concentrated where more vectors are positive for a given pathogen.

Comparative population genetics of Amblyomma maculatum and Amblyomma americanum in the mid-Atlantic United States.

The Gulf Coast tick, Amblyomma maculatum, is undergoing a northward expansion along the United States East Coast, most recently establishing populations in Virginia, Maryland, and Delaware. This expansion has human health implications, as A. maculatum is the primary natural vector of the bacterium Rickettsia parkeri, which causes a spotted fever-type rickettsiosis.

A Simple, Inexpensive Method for Mark-Recapture of Ixodid Ticks.

Mark-recapture techniques have been widely used and specialized to study organisms throughout the field of biology. To mark-recapture ticks (Ixodida), we have created a simple method to mark ticks using nail polish applied with an insect pin secured in a pencil that allows for a variety of questions to be answered. For measuring tick control efficacy, estimating population estimates, or measuring movement of ticks, this inexpensive mark-recapture method has been easily applied in the field and in the lab to provide useful data to answer a variety of questions about ticks.

A Comparison of Tick Collection Materials and Methods in Southeastern Virginia.

In field studies of tick ecology, observed patterns may be biased by sampling methods. Results can vary by species, life stage, and habitat, and understanding these biases will improve comparisons of data across studies as well as assessment of human disease risk. A direct comparison of flagging versus dragging was conducted in southeastern Virginia.

Survey of Rickettsia parkeri and Amblyomma maculatum associated with small mammals in southeastern Virginia.

Small mammals are often parasitized by the immature stages of hard-bodied ticks (family Ixodidae) and may serve as reservoir hosts of tick-borne pathogens. Amblyomma maculatum, the Gulf Coast tick, is the primary vector of Rickettsia parkeri, the causative agent of R. parkeri rickettsiosis.

Conserving spawning stocks through harvest slot limits and no-take protected areas.

The key to the conservation of harvested species is the maintenance of reproductive success. Yet for many marine species large, old, individuals are targeted despite their disproportionate contribution to reproduction. We hypothesized that a combination of no-take marine protected areas (MPAs) and harvest slot limits (maximum and minimum size limits) would result in the conservation of large spawning individuals under heavy harvest.

LYMESIM 2.0: An Updated Simulation of Blacklegged Tick (Acari: Ixodidae) Population Dynamics and Enzootic Transmission of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae).

Lyme disease is the most commonly reported vector-borne disease in the United States, and the number of cases reported each year continues to rise. The complex nature of the relationships between the pathogen (Borrelia burgdorferi sensu stricto), the tick vector (Ixodes scapularis Say), multiple vertebrate hosts, and numerous environmental factors creates challenges for understanding and predicting tick population and pathogen transmission dynamics. LYMESIM is a mechanistic model developed in the late 1990s to simulate the life-history of I.

First report of Candidatus Rickettsia mendelii in Ixodes brunneus from the United States.

Candidatus Rickettsia mendelii is a novel rickettsial species recently identified in Ixodes ricinus. In this study, Ixodes brunneus collected from wild birds (n = 77 ticks) or vegetation (n = 4 ticks) in southeastern Virginia were surveyed for rickettsial agents. Candidatus Rickettsia mendelii was confirmed in I.

A seven-legged tick: Report of a morphological anomaly in Ixodes scapularis (Acari: Ixodidae) biting a human host from the Northeastern United States.

Cases of morphological anomalies in the blacklegged tick, Ixodes scapularis (Acari: Ixodidae), have recently been reported from the Northeastern and upper Midwestern United States, potentially complicating identification of this important vector of human disease-causing pathogens. We hereby report a case of a morphological anomaly in I. scapularis, biting a human host residing in Norwich, Connecticut.

A stochastic epidemic model for the dynamics of two pathogens in a single tick population.

Understanding tick-transmitted pathogens in tick infested areas is crucial for the development of preventive and control measures in response to the increasing cases of tick-borne diseases. A stochastic model for the dynamics of two pathogens, Rickettsia parkeri and Rickettsia amblyommii, in a single tick, Amblyomma americanum, is developed and analysed. The model, a continuous-time Markov chain, is based on a deterministic tick-borne disease model.

Multistate Survey of American Dog Ticks () for Species.

, a common human-biting tick found throughout the eastern half and along the west coast of the United States, is a vector of multiple bacterial pathogens. Historically, has been considered a primary vector of , the causative agent of Rocky Mountain spotted fever. A total of 883 adult , collected between 2012 and 2017 from various locations in 12 states across the United States, were screened for rickettsial DNA.