Distribution, Dynamics, and Diversity of Questing Ticks in the Lower Midwest

2021 ◽  
Author(s):  
Chris Wojan ◽  
Thomas Thrasher ◽  
Evan Lacey ◽  
Keith Clay
Keyword(s):  
Negative Binomial ◽  
Ixodes Scapularis ◽  
Negative Binomial Regression ◽  
Dermacentor Variabilis ◽  
Early Spring ◽  
Early Summer ◽  
Amblyomma Americanum ◽  
South Central ◽  
The Status ◽  
Forested Areas

Abstract We investigated the spatiotemporal patterns of medically important tick species in southcentral Indiana in 2018 and 2019. In recent decades, both Amblyomma americanum (Acari: Ixodidae) (Linnaeus) and Ixodes scapularis (Acari: Ixodidae) (Say) have been expanding their ranges into the Midwest. We report updates to the status of A. americanum, I. scapularis, and Dermacentor variabilis (Acari: Ixodidae) (Say) across 13 counties in southern and south-central Indiana. We found more northerly establishment of A. americanum and more widespread establishment of I. scapularis than previously reported in the literature. We also provide the first report of Amblyomma maculatum (Acari: Ixodidae) (Koch) in Indiana. Using negative binomial regression, we observed significant spatial variation among sampling sites in A. americanum adults and nymphs, D. variabilis adults, and I. scapularis nymphs. Further, we found higher densities of A. americanum nymphs and I. scapularis adults in more forested areas as opposed to less forested, more developed areas. We did not find significant interannual variation in tick densities for any species. More southern sites featured higher densities of A. americanum adults and nymphs, D. variabilis adults, and I. scapularis nymphs than more northern sites. Seasonally, we observed the highest peaks in tick activity in the spring and early summer, but I. scapularis adults were most common in the early spring and fall. Average adult A. americanum and adult D. variabilis densities were positively correlated at our sites. Our results reflect the northward expansion of A. americanum in the Lower Midwest, as well as the increasing geographic prevalence of I. scapularis in the region.

scholarly journals Modeling the Distribution of Medically Important Tick Species in Florida

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 190 ◽  
Author(s):  
William H. Kessler ◽  
Claudia Ganser ◽  
Gregory E. Glass
Keyword(s):  
Habitat Suitability ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Suitable Habitat ◽  
Public Health Importance ◽  
Raising Awareness ◽  
Great Public Health

The lone star (Amblyomma americanum), black-legged (Ixodes scapularis) and American dog ticks (Dermacentor variabilis) are species of great public health importance as they are competent vectors of several notable pathogens. While the regional distributions of these species are well characterized, more localized distribution estimates are sparse. We used records of field collected ticks and an ensemble modeling approach to predict habitat suitability for each of these species in Florida. Environmental variables capturing climatic extremes were common contributors to habitat suitability. Most frequently, annual precipitation (Bio12), mean temperature of the driest quarter (Bio9), minimum temperature of the coldest month (Bio6), and mean Normalized Difference Vegetation Index (NDVI) were included in the final models for each species. Agreement between the modeling algorithms used in this study was high and indicated the distribution of suitable habitat for all three species was reduced at lower latitudes. These findings are important for raising awareness of the potential for tick-borne pathogens in Florida.

Low Abundance of Three Tick Species in the Piedmont of North Carolina

2020 ◽  
Author(s):  
Madeline P Seagle ◽  
Maximilian R Vierling ◽  
Ryan J Almeida ◽  
D Jacob Clary ◽  
Will Hidell ◽  
...  
Keyword(s):  
North Carolina ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Host Factors ◽  
Southeast United States ◽  
The North ◽  
Mecklenburg County ◽  
North Carolina Piedmont ◽  
Multiple Species

Abstract Multiple species of ticks, including Ixodes scapularis (Say, Ixodida:Ixodidae), Amblyomma americanum (L., Ixodida:Ixodidae), and Dermacentor variabilis (Say, Ixodida:Ixodidae), occur in high and increasing abundance in both the northeast and southeast United States. North Carolina is at the nexus of spread of these species, with high occurrence and abundance of I. scapularis to the north and A. americanum to the south. Despite this, there are few records of these species in the Piedmont of North Carolina, including the greater Charlotte metropolitan area. Here, we update the known occurrence and abundance of these species in the North Carolina Piedmont. We surveyed for ticks using cloth drags, CO2 traps, and leaf litter samples at a total of 79 sites within five locations: Mecklenburg County, South Mountains State Park, Stone Mountain State Park, Duke Forest, and Morrow Mountain State Park, all in North Carolina, during the late spring, summer, and fall seasons of 2019. From these surveys, we had only 20 tick captures, illuminating the surprisingly low abundance of ticks in this region of North Carolina. Our results indicate the possibility of underlying habitat and host factors limiting tick distribution and abundance in the North Carolina Piedmont.

Ticks (Acari: Ixodidae) Parasitizing Domestic Dogs in Southeastern Georgia

2004 ◽  
Vol 39 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Alan B. Wells ◽  
Lance A. Durden ◽  
John H. Smoyer
Keyword(s):  
Gulf Coast ◽  
Ixodes Scapularis ◽  
Rhipicephalus Sanguineus ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Domestic Dogs ◽  
Gopher Tortoise ◽  
Gulf Coast Tick ◽  
Dog Tick ◽  
Ixodes Affinis

Ticks (Acari: Ixodidae) were collected from family-owned domestic dogs, Canis familiaris L., in Bulloch Co., GA, from 1996 to 2003 and from dogs maintained in a shelter in Emanuel Co., GA, in 2002 and 2003. A total of 2,466 ticks representing 9 species was recovered. The most frequently recovered species from family-owned dogs were the blacklegged tick, Ixodes scapularis Say (54.6% of all ticks from this group of dogs), and American dog tick, Dermacentor variabilis (Say) (27.7%). Collections from shelter-maintained dogs were dominated by the brown dog tick, Rhipicephalus sanguineus (Latreille) (73.6%). Except for 39 nymphs of the lone star tick, Amblyomma americanum (L.), 12 nymphs of R. sanguineus, 7 nymphs of the Gulf Coast tick, Amblyomma maculatum Koch, 1 nymph of D. variabilis and 72 larvae of the gopher tortoise tick, Amblyomma tuberculatum Marx, only adult ticks were present. Seasonally, I. scapularis adults were recorded from October through May and were most common in the fall; whereas, A. americanum, A. maculatum, A. tuberculatum, D. variabilis, and Ixodes affinis Neumann were all found only during the spring, summer and/or early fall. Two species of ticks collected during this study, A. tuberculatum and I. affinis, have Coastal Plain distributions in the southern U.S. and would only be expected to parasitize dogs within this region.

scholarly journals Identification of Novel Viruses in Amblyomma americanum , Dermacentor variabilis , and Ixodes scapularis Ticks

mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Rafal Tokarz ◽  
Stephen Sameroff ◽  
Teresa Tagliafierro ◽  
Komal Jain ◽  
Simon H. Williams ◽  
...  
Keyword(s):  
New York ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Ixodes Scapularis ◽  
The United States ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Animal Pathogens ◽  
Wide Range ◽  
Sequencing Platforms

ABSTRACT Ticks carry a wide range of known human and animal pathogens and are postulated to carry others with the potential to cause disease. Here we report a discovery effort wherein unbiased high-throughput sequencing was used to characterize the virome of 2,021 ticks, including Ixodes scapularis ( n = 1,138), Amblyomma americanum ( n = 720), and Dermacentor variabilis ( n = 163), collected in New York, Connecticut, and Virginia in 2015 and 2016. We identified 33 viruses, including 24 putative novel viral species. The most frequently detected viruses were phylogenetically related to members of the Bunyaviridae and Rhabdoviridae families, as well as the recently proposed Chuviridae . Our work expands our understanding of tick viromes and underscores the high viral diversity that is present in ticks. IMPORTANCE The incidence of tick-borne disease is increasing, driven by rapid geographical expansion of ticks and the discovery of new tick-associated pathogens. The examination of the tick microbiome is essential in order to understand the relationship between microbes and their tick hosts and to facilitate the identification of new tick-borne pathogens. Genomic analyses using unbiased high-throughput sequencing platforms have proven valuable for investigations of tick bacterial diversity, but the examination of tick viromes has historically not been well explored. By performing a comprehensive virome analysis of the three primary tick species associated with human disease in the United States, we gained substantial insight into tick virome diversity and can begin to assess a potential role of these viruses in the tick life cycle.

scholarly journals Identification of public submitted tick images: A neural network approach

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260622
Author(s):  
Lennart Justen ◽  
Duncan Carlsmith ◽  
Susan M. Paskewitz ◽  
Lyric C. Bartholomay ◽  
Gebbiena M. Bron
Keyword(s):  
Public Health ◽  
Neural Network ◽  
Deep Learning ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Identification Accuracy ◽  
Small Object ◽  
Neural Network Approach ◽  
Public Health Agencies

Ticks and tick-borne diseases represent a growing public health threat in North America and Europe. The number of ticks, their geographical distribution, and the incidence of tick-borne diseases, like Lyme disease, are all on the rise. Accurate, real-time tick-image identification through a smartphone app or similar platform could help mitigate this threat by informing users of the risks associated with encountered ticks and by providing researchers and public health agencies with additional data on tick activity and geographic range. Here we outline the requirements for such a system, present a model that meets those requirements, and discuss remaining challenges and frontiers in automated tick identification. We compiled a user-generated dataset of more than 12,000 images of the three most common tick species found on humans in the U.S.: Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis. We used image augmentation to further increase the size of our dataset to more than 90,000 images. Here we report the development and validation of a convolutional neural network which we call “TickIDNet,” that scores an 87.8% identification accuracy across all three species, outperforming the accuracy of identifications done by a member of the general public or healthcare professionals. However, the model fails to match the performance of experts with formal entomological training. We find that image quality, particularly the size of the tick in the image (measured in pixels), plays a significant role in the network’s ability to correctly identify an image: images where the tick is small are less likely to be correctly identified because of the small object detection problem in deep learning. TickIDNet’s performance can be increased by using confidence thresholds to introduce an “unsure” class and building image submission pipelines that encourage better quality photos. Our findings suggest that deep learning represents a promising frontier for tick identification that should be further explored and deployed as part of the toolkit for addressing the public health consequences of tick-borne diseases.

scholarly journals Meteorological factors affecting scrub typhus occurrence: a retrospective study of Yamagata Prefecture, Japan, 1984–2014

2016 ◽  
Vol 145 (3) ◽  
pp. 462-470 ◽  
Author(s):  
J. SETO ◽  
Y. SUZUKI ◽  
R. NAKAO ◽  
K. OTANI ◽  
K. YAHAGI ◽  
...  
Keyword(s):  
Negative Binomial ◽  
Scrub Typhus ◽  
Meteorological Factors ◽  
Negative Relationship ◽  
Warning System ◽  
Negative Binomial Regression ◽  
Early Summer ◽  
Vector Borne Diseases ◽  
Cumulative Rainfall ◽  
Northern Japan

SUMMARYClimate change, by its influence on the ecology of vectors might affect the occurrence of vector-borne diseases. This study examines the effects of meteorological factors in Japan on the occurrence of scrub typhus, a mite-borne zoonosis caused byOrientia tsutsugamushi. Using negative binomial regression, we analysed the relationships between meteorological factors (including temperature, rainfall, snowfall) and spring–early summer cases of scrub typhus in Yamagata Prefecture, Japan, during 1984–2014. The average temperature in July and August of the previous year, cumulative rainfall in September of the previous year, snowfall throughout the winter, and maximum depth of snow cover in January and February were positively correlated with the number of scrub typhus cases. By contrast, cumulative rainfall in July of the previous year showed a negative relationship to the number of cases. These associations can be explained by the life-cycle ofLeptotrombidium pallidum, a predominant vector of spring–early summer cases of scrub typhus in northern Japan. Our findings show that several meteorological factors are useful to estimate the number of scrub typhus cases before the endemic period. They are applicable to establish an early warning system for scrub typhus in northern Japan.

scholarly journals Virome Analysis of Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis Ticks Reveals Novel Highly Divergent Vertebrate and Invertebrate Viruses

2014 ◽  
Vol 88 (19) ◽  
pp. 11480-11492 ◽  
Author(s):  
R. Tokarz ◽  
S. H. Williams ◽  
S. Sameroff ◽  
M. Sanchez Leon ◽  
K. Jain ◽  
...  
Keyword(s):  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum
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