Effects of Tick Control by Acaricide Self-Treatment of White-Tailed Deer on Host-Seeking Tick Infection Prevalence and Entomologic Risk forIxodes scapularis-Borne Pathogens

2009 ◽  
Vol 9 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Anne Gatewood Hoen ◽  
Lindsay G. Rollend ◽  
Michele A. Papero ◽  
John F. Carroll ◽  
Thomas J. Daniels ◽  
...  
Keyword(s):  
Tick Control ◽  
Infection Prevalence ◽  
Host Seeking ◽  
Tick Infection

scholarly journals Why Lyme disease is common in the northern US, but rare in the south: The roles of host choice, host-seeking behavior, and tick density

PLoS Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. e3001066
Author(s):  
Howard S. Ginsberg ◽  
Graham J. Hickling ◽  
Russell L. Burke ◽  
Nicholas H. Ogden ◽  
Lorenza Beati ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Disease Risk ◽  
Host Choice ◽  
Infection Prevalence ◽  
The South ◽  
The North ◽  
Host Seeking ◽  
Tick Infection ◽  
Seeking Behavior ◽  
Clear Shift

Lyme disease is common in the northeastern United States, but rare in the southeast, even though the tick vector is found in both regions. Infection prevalence of Lyme spirochetes in host-seeking ticks, an important component to the risk of Lyme disease, is also high in the northeast and northern midwest, but declines sharply in the south. As ticks must acquire Lyme spirochetes from infected vertebrate hosts, the role of wildlife species composition on Lyme disease risk has been a topic of lively academic discussion. We compared tick–vertebrate host interactions using standardized sampling methods among 8 sites scattered throughout the eastern US. Geographical trends in diversity of tick hosts are gradual and do not match the sharp decline in prevalence at southern sites, but tick–host associations show a clear shift from mammals in the north to reptiles in the south. Tick infection prevalence declines north to south largely because of high tick infestation of efficient spirochete reservoir hosts (rodents and shrews) in the north but not in the south. Minimal infestation of small mammals in the south results from strong selective attachment to lizards such as skinks (which are inefficient reservoirs for Lyme spirochetes) in the southern states. Selective host choice, along with latitudinal differences in tick host-seeking behavior and variations in tick densities, explains the geographic pattern of Lyme disease in the eastern US.

scholarly journals Impact of the experimental removal of lizards on Lyme disease risk

2011 ◽  
Vol 278 (1720) ◽  
pp. 2970-2978 ◽  
Author(s):  
Andrea Swei ◽  
Richard S. Ostfeld ◽  
Robert S. Lane ◽  
Cheryl J. Briggs
Keyword(s):  
Lyme Disease ◽  
Disease Ecology ◽  
Disease Risk ◽  
Large Fraction ◽  
Host Community ◽  
Deer Mice ◽  
Infection Prevalence ◽  
Alternate Host ◽  
Experimental Removal ◽  
Tick Infection

The distribution of vector meals in the host community is an important element of understanding and predicting vector-borne disease risk. Lizards (such as the western fence lizard; Sceloporus occidentalis ) play a unique role in Lyme disease ecology in the far-western United States. Lizards rather than mammals serve as the blood meal hosts for a large fraction of larval and nymphal western black-legged ticks ( Ixodes pacificus —the vector for Lyme disease in that region) but are not competent reservoirs for the pathogen, Borrelia burgdorferi . Prior studies have suggested that the net effect of lizards is to reduce risk of human exposure to Lyme disease, a hypothesis that we tested experimentally. Following experimental removal of lizards, we documented incomplete host switching by larval ticks (5.19%) from lizards to other hosts. Larval tick burdens increased on woodrats, a competent reservoir, but not on deer mice, a less competent pathogen reservoir. However, most larvae failed to find an alternate host. This resulted in significantly lower densities of nymphal ticks the following year. Unexpectedly, the removal of reservoir-incompetent lizards did not cause an increase in nymphal tick infection prevalence. The net result of lizard removal was a decrease in the density of infected nymphal ticks, and therefore a decreased risk to humans of Lyme disease. Our results indicate that an incompetent reservoir for a pathogen may, in fact, increase disease risk through the maintenance of higher vector density and therefore, higher density of infected vectors.

Synthetic Pyrethroid, Natural Product, and Entomopathogenic Fungal Acaricide Product Formulations for Sustained Early Season Suppression of Host-Seeking Ixodes scapularis (Acari: Ixodidae) and Amblyomma americanum Nymphs

2020 ◽  
Author(s):  
Terry L Schulze ◽  
Robert A Jordan
Keyword(s):  
Natural Product ◽  
Ixodes Scapularis ◽  
Tick Control ◽  
Amblyomma Americanum ◽  
Synthetic Pyrethroid ◽  
Activity Period ◽  
Synthetic Pyrethroids ◽  
Seasonal Activity ◽  
Early Season ◽  
Host Seeking

Abstract We compared the ability of product formulations representing a synthetic pyrethroid acaricide (Talstar P Professional Insecticide), a natural product-based acaricide (Essentria IC3), and an entomopathogenic fungal acaricide (Met52 EC Bioinsecticide) to suppress Ixodes scapularis Say and Amblyomma americanum (L.) nymphs when applied following USEPA approved manufacturers’ label recommendations for tick control using hand-pumped knapsack sprayers before the beginning of their seasonal activity period in the spring. We applied Met52 EC Bioinsecticide (11% Metarhizium anisopliae Strain F52) to five 100 m2 plots (10.6 ml AI/plot) in mid-April 2020. Two weeks later at the end of April 2020, we treated an additional five 100 m2 plots each with either Talstar P Professional Insecticide (7.9% bifenthrin @ 2.5 ml AI/plot) or Essentria IC3 (10% rosemary oil, 5% geraniol, and 2% peppermint oil @ 86.6 ml AI/plot). Weekly sampling of all plots through the end of June 2020 showed that both Met52 EC Bioinsecticide and Essentria IC3 failed to maintain a 90% suppression threshold for I. scapularis, compared to control plots, and required two additional applications over the course of the trial. In contrast, Talstar P Professional Insecticide suppressed 100% of I. scapularis nymphs and ≥96 and 100% of A. americanum nymphs and adults, respectively. Such pre-season applications of synthetic pyrethroids significantly reduce the early season acarological risk for exposure to host-seeking ticks as well as the frequency of acaricide applications.

scholarly journals Mechanistic movement models reveal ecological drivers of tick-borne pathogen spread

2021 ◽  
Vol 18 (181) ◽  
pp. 20210134
Author(s):  
Olivia Tardy ◽  
Catherine Bouchard ◽  
Eric Chamberland ◽  
André Fortin ◽  
Patricia Lamirande ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Tick Population ◽  
Infection Prevalence ◽  
Spread Rate ◽  
Infected Tick ◽  
Tick Density ◽  
Heterogeneous Landscapes ◽  
Tick Infection ◽  
Tick Borne Disease ◽  
Host Movement

Identifying ecological drivers of tick-borne pathogen spread has great value for tick-borne disease management. However, theoretical investigations into the consequences of host movement behaviour on pathogen spread dynamics in heterogeneous landscapes remain limited because spatially explicit epidemiological models that incorporate more realistic mechanisms governing host movement are rare. We built a mechanistic movement model to investigate how the interplay between multiple ecological drivers affects the risk of tick-borne pathogen spread across heterogeneous landscapes. We used the model to generate simulations of tick dispersal by migratory birds and terrestrial hosts across theoretical landscapes varying in resource aggregation, and we performed a sensitivity analysis to explore the impacts of different parameters on the infected tick spread rate, tick infection prevalence and infected tick density. Our findings highlight the importance of host movement and tick population dynamics in explaining the infected tick spread rate into new regions. Tick infection prevalence and infected tick density were driven by predictors related to the infection process and tick population dynamics, respectively. Our results suggest that control strategies aiming to reduce tick burden on tick reproduction hosts and encounter rate between immature ticks and pathogen amplification hosts will be most effective at reducing tick-borne disease risk.

scholarly journals Role of Borrelia burgdorferi Linear Plasmid 25 in Infection of Ixodes scapularis Ticks

2005 ◽  
Vol 187 (16) ◽  
pp. 5776-5781 ◽  
Author(s):  
Keith O. Strother ◽  
Aravinda de Silva
Keyword(s):  
Borrelia Burgdorferi ◽  
Genetic Manipulation ◽  
Natural Infection ◽  
Shuttle Vector ◽  
Linear Plasmid ◽  
Infection Prevalence ◽  
Infection Cycle ◽  
Tick Infection

ABSTRACT The tick-borne bacterium Borrelia burgdorferi has over 20 different circular and linear plasmids. Some B. burgdorferi plasmids are readily lost during in vitro culture or genetic manipulation. Linear plasmid 25, which is often lost in laboratory strains, is required for the infection of mice. Strains missing linear plasmid 25 (lp25−) are able to infect mice if the BBE22 gene on lp25 is provided on a shuttle vector. In this study, we examined the role of lp25 and BBE22 in tick infections. We tested the hypothesis that complementation with BBE22 in spirochetes lacking lp25 would restore the ability of spirochetes to infect ticks. A natural tick infection cycle was performed by feeding larvae on mice injected with the parental, lp25−, or lp25− BBE22-complemented spirochete strains. In addition, larvae and nymphs were artificially infected with different strains to study tick infections independent of mouse infections. B. burgdorferi missing lp25 was significantly impaired in its ability to infect larval and nymphal ticks. When an lp25− strain was complemented with BBE22, the ability to infect ticks was partially restored. Complementation with BBE22 allowed spirochetes lacking lp25 to establish short-term infections in ticks, but in most cases the infection prevalence was lower than that of the wild-type strain. In addition, the number of infected ticks decreased over time, suggesting that another gene(s) on lp25 is required for long-term persistence in ticks and completion of a natural infection cycle.

scholarly journals 1338. Development of a Novel Application for Differential Diagnosis of Tick-borne Diseases

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S484-S485
Author(s):  
Corey Meyer ◽  
Jaleal Sanjak ◽  
Audrey Cerles ◽  
Christian Garnier ◽  
Laurel MacMillan
Keyword(s):  
Risk Factors ◽  
Differential Diagnosis ◽  
Environmental Risk ◽  
Risk Measure ◽  
Diagnostic Testing ◽  
Biomedical Literature ◽  
Infection Prevalence ◽  
Surveillance Systems ◽  
Tick Infection ◽  
Diagnosis Model

Abstract Background Early diagnosis and treatment of tick-borne diseases (TBDs) is critical for mitigating their adverse health outcomes, but the differential diagnosis of TBDs is challenging because many symptoms are nonspecific and commonly used diagnostic assays have significant shortcomings. Furthermore, although the local incidence of TBDs is recognized as an important factor in diagnosis, tools to help clinicians formally consider surveillance data in their decision-making are not available. To address these gaps, Gryphon Scientific developed a differential diagnosis application (app) for TBDs that calculates a patient’s likelihood of infection with specific TBDs based on their symptoms, risk factors, and state of suspected tick exposure. Methods A differential diagnosis model for TBDs was developed using data on: (1) TBD symptom and risk factor prevalence in TBD patient populations, collected from clinical studies; and (2) human TBD incidence data from notifiable disease surveillance systems and tick infection prevalence data from reports and public databases, which were combined to develop an environmental risk measure. These data were used to build a Bayesian Belief Network (BBN) model that predicts TBD infection probabilities based on a patient’s symptoms, risk factors, and state of suspected tick exposure. Performance of the model was validated using case studies from the biomedical literature. The model was incorporated into an app developed using R-shiny, called TBD-DDx (Figures 1 and 3). Results A pilot application was developed that includes 10 states (AR, CT, MA, ME, MN, MO, NH, RI, VT, and WI) and the 11 TBDs endemic to those states. The differential diagnosis model identified the patient’s true disease as the top-predicted disease in 56% of cases and within the top three predicted TBD in 84% of cases. The inclusion of incidence factors in the model improved performance (Figure 4). Conclusion These results demonstrate that the TBD-DDx app is a promising tool for informing clinical diagnoses of TBDs to guide selection of diagnostic testing and treatment. This study represents the first use of a BBN modeling approach that incorporates an environmental risk measure and could be adapted for differential diagnosis of other diseases with environmental or other exposure risks. Disclosures All authors: No reported disclosures.

scholarly journals Ability of Two Commercially Available Host-Targeted Technologies to Reduce Abundance of Ixodes scapularis (Acari: Ixodidae) in a Residential Landscape

2019 ◽  
Vol 56 (4) ◽  
pp. 1095-1101 ◽  
Author(s):  
Robert A Jordan ◽  
Terry L Schulze
Keyword(s):  
Control System ◽  
Treatment Effect ◽  
Tick Infestation ◽  
Ixodes Scapularis ◽  
Tick Control ◽  
Conclusive Evidence ◽  
Measurable Effect ◽  
Treated Area ◽  
Host Seeking ◽  
Nymphal Tick

Abstract Host-targeted technologies provide an alternative to the use of conventional pesticide applications to reduce the abundance of Ixodes scapularis Say, the vector for an array of tick-associated human diseases. We compared the ability of Damminx Tick Tubes (Damminix) and SELECT Tick Control System (Select TCS) bait boxes to control host-seeking I. scapularis nymphs in a wooded residential environment. Small mammals accepted and used Select TCS bait boxes with greater frequency compared to Damminix tubes over the course of the 2-yr trial. Nymphal tick infestation prevalence and intensity on captured mice and chipmunks provided no conclusive evidence of a treatment effect during May–June of both years. However, both treatments had a measurable effect on larval tick burdens in July–August and the magnitude of the effect was greater at the Select TCS-treated area and reflected the fact that Select TCS effectively treated chipmunks, while Damminix did not. Deployment of Damminix resulted in 27.6 and 20.3% control of questing nymphs in treated areas at 1 yr and 2 yr postintervention, while Select TCS bait boxes provided 84.0 and 79.1% control, respectively. The economics of residential tick control using these products in wooded residential landscapes is discussed.

scholarly journals Lyme neuroborreliosis and bird populations in northern Europe

2019 ◽  
Vol 286 (1903) ◽  
pp. 20190759 ◽  
Author(s):  
Atle Mysterud ◽  
Dieter J. A. Heylen ◽  
Erik Matthysen ◽  
Aïda Lopez Garcia ◽  
Solveig Jore ◽  
...  
Keyword(s):  
Lyme Borreliosis ◽  
Clinical Symptoms ◽  
Disease Incidence ◽  
Time Lag ◽  
Lyme Neuroborreliosis ◽  
Infection Prevalence ◽  
Host Group ◽  
Host Seeking ◽  
Vector Borne

Many vector-borne diseases are transmitted through complex pathogen–vector–host networks, which makes it challenging to identify the role of specific host groups in disease emergence. Lyme borreliosis in humans is now the most common vector-borne zoonosis in the Northern Hemisphere. The disease is caused by multiple genospecies of Borrelia burgdorferi sensu lato bacteria transmitted by ixodid (hard) ticks, and the major host groups transmit Borrelia genospecies with different pathogenicity, causing variable clinical symptoms in humans. The health impact of a given host group is a function of the number of ticks it infects as well as the pathogenicity of the genospecies it carries. Borrelia afzelii , with mainly small mammals as reservoirs, is the most common pathogen causing Lyme borreliosis, and it is often responsible for the largest proportion of infected host-seeking tick nymphs in Europe. The bird-borne Borrelia garinii , though less prevalent in nymphal ticks, is more likely to cause Lyme neuroborreliosis, but whether B. garinii causes disseminated disease more frequently has not been documented. Based on extensive data of annual disease incidence across Norway from 1995 to 2017, we show here that 69% of disseminated Lyme borreliosis cases were neuroborreliosis, which is three times higher than predicted from the infection prevalence of B. garinii in host-seeking ticks (21%). The population estimate of migratory birds, mainly of thrushes, explained part of the annual variation in cases of neuroborreliosis, with a one-year time lag. We highlight the important role of the genospecies' pathogenicity and the host associations for understanding the epidemiology of disseminated Lyme borreliosis.

scholarly journals Modeling the role of songbirds and rodents in the ecology of Lyme disease

2000 ◽  
Vol 78 (12) ◽  
pp. 2184-2197 ◽  
Author(s):  
Antonia R Giardina ◽  
Kenneth A Schmidt ◽  
Eric M Schauber ◽  
Richard S Ostfeld
Keyword(s):  
New York ◽  
Lyme Disease ◽  
Ixodes Scapularis ◽  
New York State ◽  
Original Data ◽  
Etiologic Agent ◽  
Host Community ◽  
Infection Prevalence ◽  
Tick Infection ◽  
Tick Vectors

Small rodents such as the white-footed mouse (Peromyscus leucopus) and the eastern chipmunk (Tamias striatus) efficiently transmit Borrelia burgdorferi, the etiologic agent of Lyme disease, to feeding ticks, whereas other hosts of ticks are less efficient reservoirs of B. burgdorferi. We examined the roles of ground-foraging and ground-nesting songbirds as alternative hosts for ticks, focusing on their potential to dilute the infection prevalence of ticks (Ixodes scapularis, the black-legged tick) with B. burgdorferi. We developed a mathematical model based on the relative use by ticks of rodent and bird hosts across varying host densities. We parameterized the model for sites in southeastern New York State using original data and for the northeastern United States using published values. Our results indicate that American robins (Turdus migratorius), ovenbirds (Seiurus aurocapillus), veeries (Catharus fuscescens), and wood thrushes (Hylocichla mustelina) have a low capacity to dilute the prevalence of tick infection, particularly when rodents are at moderate to high densities. We attribute this result to low use by ticks of birds and a low density of birds relative to that of rodents. Only when rodents constitute less than ca. 10-20% of the combined rodent and songbird host community are birds capable of substantially reducing the infection prevalence of ticks. In years or habitat types in which the density of rodents is low but that of ground-dwelling songbirds is high, the risk of human exposure to Lyme disease may reduced because birds dilute the infection prevalence of tick vectors.

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