Statewide passive tick surveillance using companion animals in Delaware reveals 9 tick species (Acari: Ixodidae) and 6 associated pathogens.

Tick species infesting humans in the United States

Ticks (Acari: Ixodida) on synanthropic small and medium-sized mammals in areas of the northeastern United States infested with the Asian longhorned tick, Haemaphysalis longicornis

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

In the late 20th century, elk ( Cervus canadensis) were reintroduced into southeastern Kentucky, US. This population has since been used as a stock population for additional elk reintroductions in other eastern states. Although reintroduction and translocation practices are effective, they can disseminate vectors and pathogens. Therefore, we surveyed tick species residing on elk hosts a decade after elk reintroduction in Kentucky by examining 263 captured individuals (female=86; male=177) from 2011 to 2013. A total of 1,617 ticks were collected from 255 elk. We found five tick species: American dog ( Dermacentor variabilis), Gulf Coast ( Amblyomma maculatum), winter ( Dermacentor albipictus), deer ( Ixodes scapularis), and Lone Star ( Amblyomma americanum). The most prevalent ticks were winter tick (52.3%) and American dog tick (42.1%). We found no difference between female and male elk in mean intensity of American dog tick (mean=2.6, 95% confidence limits: -2.6, 2.7; P=0.701) or winter tick (mean=3.28, 95% confidence limits: -2.21, 2.07; P=0.274). Our findings demonstrated that the elk population acts as host to a diversity of tick species, suggested a broader distribution of tick species than previously reported in Kentucky, and highlighted the potential for inadvertent spread of ticks through translocation and reintroduction efforts, even on a local scale.

Association of the invasive Haemaphysalis longicornis tick with vertebrate hosts, other native tick vectors, and tick-borne pathogens in New York City, USA

There is an alarming increase in the population of ticks and tick-borne diseases (TBDs), with 475,000 cases reported annually, some of which are fatal. Due to limited training, healthcare providers and the public cannot always accurately identify ticks and their associated infections, leading to delayed diagnoses and treatments. Additionally, the prevalence rates of different disease-causing pathogens vary based on geographic locations. To facilitate the identification process and provide an expedited risk assessment of TBDs, a machine learning-based iOS application, DETICKT IT was created. The app features a ResNet50V2 (transfer learning) deep convolutional neural network (CNN) built in Python for combining real-time tick-species identification with a location-based tick-risk assessment by embedding the Centers for Disease Control and Prevention’s (CDC’s) spatiotemporal tick and pathogen surveillance statistics. With DETICKT IT, users can now receive an immediate and accurate analysis to determine whether they are at risk of contracting a certain TBD. The app is able to accurately identify the ten most common tick species in North and South America: American dog tick (Dermacentor variabilis, D. similis), Asian longhorned tick (Haemaphysalis longicornis), Brown dog tick (Rhipicephalus sanguineus), Eastern blacklegged tick (Ixodes scapularis), Western blacklegged tick (Ixodes pacificus), Groundhog tick (Ixodes cookei), Gulf Coast tick (Amblyomma maculatum), Lone star tick (Amblyomma americanum), Rocky Mountain wood tick (Dermacentor andersoni), and soft tick (Ornithodoros). The overall accuracy is 97% with precision, recall, and F1 score metrics of 0.96, 0.97, and 0.96, respectively. This freely accessible app shows promise in assisting tick bite victims with their decision to seek further medical assistance, particularly those with underlying health conditions.

Current knowledge of tick distribution and tick-borne pathogen presence across Louisiana is limited. Collaborating with veterinarians across the state, ticks removed from companion animals were recovered and assessed for the presence of zoonotic pathogens. A large number of ticks (n = 959) were removed from companion animals and subsequently screened using qPCR for Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, Bartonella henselae, Ehrlichia chaffeensis, and spotted fever group Rickettsia. Five different tick species, Ixodes scapularis (54.5%), Amblyomma americanum (18.4%), Amblyomma maculatum (12.5%), Dermacentor variabilis (11.2%), and Rhipicephalus sanguineus (0.3%) from different regions of Louisiana were collected from October 2018 to July 2019. There were 15 PCR-positive ticks for Rickettsia parkeri (1.6% prevalence), and four ticks were positive for Ehrlichia chaffeensis (0.4% prevalence). This survey identifies ticks and tick-borne pathogens associated with companion animals and areas for future active surveillance.

BackgroundTicks are common on horses, but recent publications characterizing equine tick infestations in North America are lacking.MethodsTo further understand attachment site preferences of common ticks of horses, and to document the seasonality of equine tick infestation in northeastern Oklahoma, horses from eight farms were evaluated twice a month over a 1-year period. Each horse was systematically inspected beginning at the head and moving caudally to the tail. Attachment sites of ticks were recorded and all ticks collected were identified to species and stage.ResultsHorses (26 males and 62 females) enrolled in the study ranged in age from 1 to 23 years (mean = 12, 95% CI 11–13). A total of 2731 ticks were collected; 84.1% (74/88) of the horses were infested (median = 3 ticks) at one or more examinations. Five tick species were identified, including Amblyomma americanum (78.2%; 2136/2731), Ixodes scapularis (18.2%; 497/2731), Dermacentor albipictus brown variant (2.6%; 71/2731), Dermacentor variabilis (0.7%; 20/2731), and Amblyomma maculatum (0.3%; 7/231). Most ticks were adults (83.6%; 2282/2731), but immature A. americanum (436/2136; 20.4%), D. albipictus (12/71; 16.9%), and A. maculatum (n = 1) were occasionally recovered. Amblyomma americanum were most often attached to the inguinal area, and I. scapularis and D. albipictus were most commonly found on the chest and axillary region (P < 0.0001). Ticks were found on horses in every month of the year. The largest number of ticks (638/2731; 23.4%) were collected in May (P < 0.0001). Amblyomma americanum, primarily immature, was the only tick recovered in September, I. scapularis and D. albipictus predominated October through February, and both A. americanum and I. scapularis were common in March. In the warmer months, April through August, A. americanum was the most common tick, followed by D. variabilis and A. maculatum.ConclusionsThis research confirms that ticks common on horses in North America have attachment site preferences and that ticks infest horses in Oklahoma throughout the year, including during the winter. Additional research is warranted to fully understand the risk these infestations pose to equine health.Graphical abstract

Establishing a baseline for tick surveillance in Alaska: Tick collection records from 1909-2019

Ticks are common on horses, but there is a dearth of contemporary data on infestation prevalence, predominant species, and tick-borne disease agents important in this host. To determine the species of ticks most common on horses and the prevalence of equine exposure to and infection with tick-borne disease agents, ticks and blood samples were collected from 73 horses during May, June, and July of 2010. Adult ticks were identified to species, and antibodies to Ehrlichia spp., Anaplasma spp., and Borrelia burgdorferi were identified using indirect fluorescence antibody assay, a commercial point-of-care enzyme-linked immunosorbent assay, or both. In total, 1,721 ticks were recovered at the majority (85%) of equid examinations. Amblyomma americanum (L.) was the most common tick collected (1,598 out of 1,721; 92.9%) followed by Dermacentor variabilis (Say, 1821) (85 out of 1,721; 4.9%) and Amblyomma maculatum Koch, 1844 (36 out of 1,721; 2.1%); single specimens of Ixodes scapularis Say, 1821 and Dermacentor albipictus (Packard, 1869) were also identified. Antibodies reactive to Ehrlichia spp. were found in 18 out of 73 (24.7%) of horses tested, and were more commonly identified in horses with moderate or high tick infestations than those with low tick infestations (P < 0.001). These data support A. americanum as the most common tick species infesting horses in central Oklahoma from May through July and suggest horses are also commonly exposed to an Ehrlichia sp.

109 - Ticks

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations with four North American tick species ( Dermacentor variabilis, Ixodes scapularis, Amblyomma americanum and Amblyomma maculatum) on dogs

Abiotic Factors Contributing to the Survival of Three Tick Species in Southeastern Virginia, Amblyomma Americanum (Lone Star Tick), Dermacentor Variabilis (American Dog Tick), and Amblyomma Maculatum (Gulf Coast Tick)

BackgroundTick-transmitted rickettsial diseases, such as ehrlichiosis and spotted fever rickettsiosis, are significant sources of morbidity and mortality in the southern United States. Because of their exposure in tick-infested woodlands, outdoor workers experience an increased risk of infection with tick-borne pathogens. As part of a double blind randomized-controlled field trial of the effectiveness of permethrin-treated clothing in preventing tick bites, we identified tick species removed from the skin of outdoor workers in North Carolina and tested the ticks for Rickettsiales pathogens.MethodsTicks submitted by study participants from April-September 2011 and 2012 were identified to species and life stage, and preliminarily screened for the genus Rickettsia by nested PCR targeting the 17-kDa protein gene. Rickettsia were further identified to species by PCR amplification of 23S-5S intergenic spacer (IGS) fragments combined with reverse line blot hybridization with species-specific probes and through cloning and nucleotide sequence analysis of 23S-5S amplicons. Ticks were examined for Ehrlichia and Anaplasma by nested PCR directed at the gltA, antigen-expressing gene containing a variable number of tandem repeats, 16S rRNA, and groESL genes.ResultsThe lone star tick (Amblyomma americanum) accounted for 95.0 and 92.9% of ticks submitted in 2011 (n = 423) and 2012 (n = 451), respectively. Specimens of American dog tick (Dermacentor variabilis), Gulf Coast tick (Amblyomma maculatum) and black-legged tick (Ixodes scapularis) were also identified. In both years of our study, 60.9% of ticks tested positive for 17-kDa. “Candidatus Rickettsia amblyommii”, identified in all four tick species, accounted for 90.2% (416/461) of the 23S-5S-positive samples and 52.9% (416/787) of all samples tested. Nucleotide sequence analysis of Rickettsia-specific 23S-5S IGS, ompA and gltA gene fragments indicated that ticks, principally A. americanum, contained novel species of Rickettsia. Other Rickettsiales, including Ehrlichia ewingii, E. chaffeensis, Ehrlichia sp. (Panola Mountain), and Anaplasma phagocytophilum, were infrequently identified, principally in A. americanum.ConclusionsWe conclude that in North Carolina, the most common rickettsial exposure is to R. amblyommii carried by A. americanum. Other Rickettsiales bacteria, including novel species of Rickettsia, were less frequently detected in A. americanum but are relevant to public health nevertheless.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-014-0607-2) contains supplementary material, which is available to authorized users.

Collared peccaries, Tayassu tajacu, collected in Hidalgo County, New Mexico, in 1964 and 1973 were found to be irregular hosts the sucking louse, Pecaroecus javalii Babcock and Ewing (Haematopinidae), the spinose ear tick, Otobius megnini (Dug'es) (Argasidae), and a psoroptid ear mite, heretofore unrecorded from North America, thought to be Trouessalges pecari da Fonseca (Psoroptidae). Also collected were the winter tick, Dermacentor albipictus (Packard) (Ixodidae), from a peccary, and 0. megnini from a bobcat skin, Lynx rufus (Felidae). A summary previously unpublished tick (Ixodoidea) collections from the peccary, deposited at the Rocky Mountain Laboratory, Hamilton, Montana, is included. Babcock and Ewing (1938) described a new genus and species sucking louse, Pecaroecus javalii Babcock and Ewing (Haematopinidae), from a collared peccary, Tayassu tajacu (as Pecari angulatus), collected about 12 miles west Juno, Val Verdi County, Texas, on 29 January 1932. They also mentioned that mites of a species Sarcoptidae were found within many the attached empty egg shells this new louse, but that no mites were found on the skin the host. Menzies et al. (1951) reported the same giant sucking louse (as P. javalli [sic]) from peccaries (as Tayassu angulatum) west the Pecos River, in Terrell County, Texas; Eads (1951) published a note on the occurrence P. javalli [sic] on one 20 peccaries, examined over a 5-year period, which had been shot in Aransas, Kleberg, Nueces, Terrell, and Uvalde counties, Texas, and reported the presence the peccary flea, Pulex porcinus Jordan and Rothschild, on all them. He also reported finding the ixodid ticks, Amblyomma americanum (L.), A. cajennense (F.), A. maculatum Koch, Dermacentor variabilis (Say), and Ixodes scapularis Say, but did not identify which ticks came from which counties. Neal (1959) reported external parasites from 85 peccaries in Arizona, as follows: Pecaroecus javellii [sic] on 7; the human flea, Pulex irritans L., and the tropical hen flea, Echidnophaga gallinacea (Westwood) on 3; Ornithodoros turicata (Dug'es) (Argasidae) on 1; and Dermacentor albipictus (Pack.) on 1. Rapp and Jones (1962) recorded Percaroecus [sic] javalii from the same species tayassuid Received for publication 28 January 1975. (as Pecarii tojacu [sic] sonoriensis) from Pima County, Arizona. McDaniel et al. (1966) recorded collections the giant sucking louse from the type locality, and Samson and Donaldson (1968) recovered 3 and 13 lice (P. javalii) from around the eyes 2 30 peccaries (as Tayassu tajacu sonoriensis) in southwestern New Mexico. Cooley (1938) republished the record for Dermacentor halli McIntosh, 1932 (Ixodidae) from peccaries in southern Texas. Samuel and Low (1970) collected giant sucking lice from the peccary (as Dicotyles tajacu angulatus) from locations in Crockett and Brewster counties in western Texas and the ixodid ticks, Amblyomma cajennense, A. inornatum Banks, Dermacentor variabilis, and Haemaphysalis-leporis palustris (Packard), from the same host species from locations in Kleberg and San Patricio counties in southern Texas. They also recorded the peccary flea, Pulex porcinus, from all four locations. Previously unpublished records Ixodoidea, now residing in the collection the Rocky Mountain Laboratory, from peccaries, have been made available to me (Table I). These include 1 female Ornithodoros turicata from Pima County, Arizona; 4 collections Amblyomma cajennense from Live Oak, Willacy, and Kenedy counties, Texas; 1 collection A. imitator Kohls from somewhere in Mexico; 1 collection Boophilus annulatus (Say) from the King Ranch in Texas; 1 collection Dermacentor halli from somewhere in Mexico and 1 from the King Ranch; and 3 collections D. variabilis from Willacy and Dimmit counties, Texas (Fig. 1).