scholarly journals Efficacy of low-dose fipronil bait against blacklegged tick (Ixodes scapularis) larvae feeding on white-footed mice (Peromyscus leucopus) under simulated field conditions

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
David M. Poché ◽  
Kelsey Dawson ◽  
Batchimeg Tseveenjav ◽  
Richard M. Poché
Keyword(s):  
Low Dose ◽  
Ixodes Scapularis ◽  
Peromyscus Leucopus ◽  
Effective Means ◽  
Plasma Concentrations ◽  
The United States ◽  
Human Infection ◽  
Field Conditions ◽  
Alternative Diet ◽  
Simulated Field

Abstract Background Lyme disease, caused primarily by Borrelia burgdorferi sensu stricto, is the most prevalent vector-borne disease in the United States. Treatment of rodent pathogen reservoirs with an oral acaricide may suppress the production of infected host-seeking ticks posing a risk for human infection. A previous study showed that an oral fipronil bait effectively controlled larval Ixodes scapularis ticks on white-footed mice (Peromyscus leucopus) up to 15 days post-bait exposure. The present study expands upon this finding by exposing group-housed white-footed mice to fipronil bait under simulated field conditions prior to tick infestation. Methods Mice (n = 80) were housed in groups of 10 within large enclosures and offered a choice between fipronil bait within a commercial bait station and an alternative diet. The mice were assigned to two treatment groups and two control groups to undergo bait exposure durations of either 24 h (reduced) or 168 h (extended). Groups were further differentiated by the time point post-bait exposure when larval ticks were applied to mice within feeding capsules (reduced day 1, day 15; extended day 21, day 35). For 4 days post-tick introduction, attached larvae were observed by microscopy and replete larvae were recovered. Replete larvae were monitored for molting success. Plasma was collected from all treatment group mice to obtain fipronil plasma concentrations (CP). Results The fipronil bait (0.005% fipronil) was palatable and controlled larval ticks on white-footed mice when presented under simulated field conditions. Efficacy in preventing attached larvae from feeding to repletion was 100% (day 1), 89.0% (day 15), 85.8% (day 21), and 75.2% (day 35). When also considering molting success, the fipronil bait prevented 100% (day 1), 91.1% (day 15), 91.7% (day 21), and 82.5% (day 35) of larvae attaching to mice from molting. The mean CP per mouse was 191.5 ng/ml (day 1), 29.4 ng/ml (day 15), 10.6 ng/ml (day 21), and 1.0 ng/ml (day 35). Conclusions The results suggest that fipronil bait will be consumed by white-footed mice in the presence of an alternative diet, and effectively control larval ticks on treated mice. A field trial is needed to confirm the results of this study. Low-dose fipronil bait may provide a cost-effective means of controlling blacklegged ticks to be integrated into tick management programs. Graphical Abstract

scholarly journals Efficacy of a low dose fipronil bait against blacklegged tick (Ixodes scapularis) larvae feeding on white-footed mice (Peromyscus leucopus) under laboratory conditions

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
David M. Poché ◽  
Gregory Franckowiak ◽  
Tyler Clarke ◽  
Batchimeg Tseveenjav ◽  
Larisa Polyakova ◽  
...  
Keyword(s):  
Low Dose ◽  
Ixodes Scapularis ◽  
Peromyscus Leucopus ◽  
Blacklegged Tick ◽  
Laboratory Conditions

scholarly journals Experimental Demonstration of Reservoir Competence of the White-Footed Mouse, Peromyscus leucopus (Rodentia: Cricetidae), for the Lyme Disease Spirochete, Borrelia mayonii (Spirochaetales: Spirochaetaceae)

2019 ◽  
Vol 57 (3) ◽  
pp. 927-932
Author(s):  
Christina M Parise ◽  
Nicole E Breuner ◽  
Andrias Hojgaard ◽  
Lynn M Osikowicz ◽  
Adam J Replogle ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Confidence Interval ◽  
Ixodes Scapularis ◽  
Peromyscus Leucopus ◽  
The United States ◽  
Sensu Stricto ◽  
Infection Prevalence ◽  
Experimental Demonstration ◽  
White Footed Mouse ◽  
Time Point

Abstract The white-footed mouse, Peromyscus leucopus (Rafinesque), is a reservoir for the Lyme disease spirochete Borrelia burgdorferi sensu stricto in the eastern half of the United States, where the blacklegged tick, Ixodes scapularis Say (Acari: Ixodidae), is the primary vector. In the Midwest, an additional Lyme disease spirochete, Borrelia mayonii, was recorded from naturally infected I. scapularis and P. leucopus. However, an experimental demonstration of reservoir competence was lacking for a natural tick host. We therefore experimentally infected P. leucopus with B. mayonii via I. scapularis nymphal bites and then fed uninfected larvae on the mice to demonstrate spirochete acquisition and passage to resulting nymphs. Of 23 mice fed on by B. mayonii-infected nymphs, 21 (91%) developed active infections. The infection prevalence for nymphs fed as larvae on these infected mice 4 wk post-infection ranged from 56 to 98%, and the overall infection prevalence for 842 nymphs across all 21 P. leucopus was 75% (95% confidence interval, 72–77%). To assess duration of infectivity, 10 of the P. leucopus were reinfested with uninfected larval ticks 12 wk after the mice were infected. The overall infection prevalence for 480 nymphs across all 10 P. leucopus at the 12-wk time point was 26% (95% confidence interval, 23–31%), when compared with 76% (95% confidence interval, 71–79%) for 474 nymphs from the same subset of 10 mice at the 4-wk time point. We conclude that P. leucopus is susceptible to infection with B. mayonii via bite by I. scapularis nymphs and an efficient reservoir for this Lyme disease spirochete.

scholarly journals Spatial and temporal patterns of the emerging tick-borne pathogen Borrelia miyamotoi in blacklegged ticks (Ixodes scapularis) in New York

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
F. Keesing ◽  
D. J. McHenry ◽  
M. H. Hersh ◽  
R. S. Ostfeld
Keyword(s):  
New York ◽  
Ixodes Scapularis ◽  
Quantitative Polymerase Chain Reaction ◽  
Human Infection ◽  
Ixodid Ticks ◽  
Transovarial Transmission ◽  
Infection Prevalence ◽  
Borrelia Miyamotoi ◽  
Spatial And Temporal Patterns ◽  
Reservoir Hosts

AbstractBorrelia miyamotoi, a bacterium that causes relapsing fever, is found in ixodid ticks throughout the northern hemisphere. The first cases of human infection with B. miyamotoi were identified in 2011. In the eastern USA, blacklegged ticks (Ixodes scapularis) become infected by feeding on an infected vertebrate host, or through transovarial transmission. We surveyed B. miyamotoi prevalence in ticks within forested habitats in Dutchess County, New York, and identified possible reservoir hosts. To assess spatial variation in infection, we collected questing nymphal ticks at > 150 sites. To assess temporal variation in infection, we collected questing nymphs for 8 years at a single study site. We collected questing larval ticks from nine plots to estimate the amount of transovarial transmission. To evaluate potential reservoir hosts, we captured 14 species of mammal and bird hosts naturally infested with larval blacklegged ticks and held these hosts in the laboratory until ticks fed to repletion and molted to nymphs. We determined infection for all ticks using quantitative polymerase chain reaction. The overall infection prevalence of questing nymphal ticks across all sites was ~ 1%, but prevalence at individual sites was as high as 9.1%. We detected no significant increase in infection through time. Only 0.4% of questing larval ticks were infected. Ticks having fed as larvae from short-tailed shrews, red squirrels, and opossums tended to have higher infection prevalence than did ticks having fed on other hosts. Further studies of the role of hosts in transmission are warranted. The locally high prevalence of B. miyamotoi in the New York/New England landscape suggests the importance of vigilance by health practitioners and the public.

scholarly journals Development of a Surgical Video Atlas for Resident Education: 3-Year Experience

OTO Open ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 2473974X2093906
Author(s):  
C. Scott Brown ◽  
Calhoun D. Cunningham ◽  
Walter T. Lee ◽  
Liana Puscas
Keyword(s):  
Operating Room ◽  
Teaching And Learning ◽  
Resident Education ◽  
Surgical Simulation ◽  
Clinical Care ◽  
Effective Means ◽  
The United States ◽  
Surgical Video ◽  
Key Indicator ◽  
Work Hour

Objective To create a high-quality annotated online surgical video atlas of key indicator otolaryngology cases and assess its use and overall journal trends over time. Methods Videos are recorded from multiple viewpoints within the operating room and compiled into a single stream. Postediting includes chaptering videos and overlaying relevant text annotations. Videos are published online and viewership trends analyzed. Results Over 3 years, 29 otolaryngology videos were published out of 161 journal publications (18%). Eight of the 14 key indicator procedures are included (57%). From the beginning of 2017 to the end of 2019, viewership of otolaryngology pages increased from 548 to 11,139 views per month, totaling >150,000 views. These now represent 10% of the total journal monthly views and 10% of the overall views. Users originate from the United States and from >10 other countries. Discussion Residents and faculty face challenges of providing the highest standard of clinical care, teaching, and learning in and out of the operating room. Inherent difficulties of surgical training, high-fidelity surgical simulation, and imposed work hour restrictions necessitate additional, more efficient and effective means of teaching and learning. Surgical videos demonstrating key anatomy, procedural steps, and surgical dexterity with hand positioning are increasing in their popularity among learners. Implications for Practice Surgical video atlases provide a unique adjunct for resident education. They are enduring and easily accessible. In a climate of work hour restrictions or elective case reduction, they may supplement how residents learn to operate outside the operating theater.

scholarly journals Human Coinfection withBorrelia burgdorferiandBabesia microtiin the United States

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Kristen L. Knapp ◽  
Nancy A. Rice
Keyword(s):  
United States ◽  
Lyme Disease ◽  
Causative Agent ◽  
Ixodes Scapularis ◽  
Immunological Response ◽  
The United States ◽  
Babesia Microti ◽  
Current State ◽  
Tick Borne Disease ◽  
Multiple Pathogens

Borrelia burgdorferi, the causative agent of Lyme disease, andBabesia microti, a causative agent of babesiosis, are increasingly implicated in the growing tick-borne disease burden in the northeastern United States. These pathogens are transmitted via the bite of an infected tick vector,Ixodes scapularis, which is capable of harboring and inoculating a host with multiple pathogens simultaneously. Clinical presentation of the diseases is heterogeneous and ranges from mild flu-like symptoms to near-fatal cardiac arrhythmias. While the reason for the variability is not known, the possibility exists that concomitant infection with bothB. burgdorferiandB. microtimay synergistically increase disease severity. In an effort to clarify the current state of understanding regarding coinfection withB. burgdorferiandB. microti, in this review, we discuss the geographical distribution and pathogenesis of Lyme disease and babesiosis in the United States, the immunological response of humans toB. burgdorferiorB. microtiinfection, the existing knowledge regarding coinfection disease pathology, and critical factors that have led to ambiguity in the literature regarding coinfection, in order to eliminate confusion in future experimental design and investigation.

Potentiation of Mivacurium Blockade by Low Dose of Pancuronium

2003 ◽  
Vol 98 (5) ◽  
pp. 1057-1062 ◽  
Author(s):  
Cyrus Motamed ◽  
Riad Menad ◽  
Robert Farinotti ◽  
Krassen Kirov ◽  
Xavier Combes ◽  
...  
Keyword(s):  
Acetylcholine Receptors ◽  
Low Dose ◽  
Cholinesterase Activity ◽  
Plasma Concentrations ◽  
Orotracheal Intubation ◽  
Plasma Cholinesterase ◽  
Neuromuscular Blocking ◽  
Pharmacokinetic Analysis ◽  
Plasma Cholinesterase Activity ◽  
Before And After

Background Mivacurium is potentiated by pancuronium to a much greater extent than other relaxants. In a previous investigation we suggested that this potentiation could be due to the ability of pancuronium to inhibit plasma cholinesterase activity, but we did not measure plasma concentrations of mivacurium. In the current study we performed a pharmacokinetic analysis by measuring the plasma concentration of mivacurium when preceded by administration of a low dose of pancuronium. Methods After induction of general anesthesia with propofol and fentanyl and orotracheal intubation, 10 patients (pancuronium-mivacurium group) received 15 microg/kg pancuronium followed 3 min later by 0.1 mg/kg mivacurium, whereas 10 other patients (mivacurium group) received saline followed by 0.13 mg/kg mivacurium 3 min later. Plasma cholinesterase activity was measured before and 3 and 30 min after pancuronium dosing in the pancuronium-mivacurium group and was measured before and after administration of saline in the mivacurium group. Arterial plasma concentrations of mivacurium and its metabolites were measured at 0.5, 1, 1.5, 2, 4, 10, 20, and 30 min after injection. Neuromuscular blockade was assessed by mechanomyography. Results Plasma cholinesterase activity decreased by 26% in the pancuronium-mivacurium group 3 min after injection of pancuronium (P < 0.01) and returned to baseline values 30 min later; however, no significant variation was observed in the mivacurium group. The clearances of the two most active isomers (Cis-Trans and Trans-Trans) were lower in the pancuronium-mivacurium group (17.6 +/- 5.1, 14.7 +/- 5.3 ml. min-1. kg-1, respectively) than in the mivacurium group (32.4 +/- 20.2, 24.8 +/- 13.5 ml. min-1. kg-1; P < 0.05). Conclusions A subparalyzing dose of pancuronium decreased plasma cholinesterase activity and the clearance of the two most active isomers of mivacurium. Pancuronium potentiates mivacurium more than other neuromuscular blocking agents because, in addition to its occupancy of postsynaptic acetylcholine receptors, it slows down the hydrolysis of mivacurium.

scholarly journals The hamster as a secondary reservoir host of lymphocytic choriomeningitis virus

1976 ◽  
Vol 76 (2) ◽  
pp. 299-306 ◽  
Author(s):  
H. H. Skinner ◽  
E. H. Knight ◽  
L. S. Buckley
Keyword(s):  
Early Pregnancy ◽  
Lymphocytic Choriomeningitis ◽  
Reservoir Host ◽  
Lymphocytic Choriomeningitis Virus ◽  
Field Conditions ◽  
Natural Reservoir ◽  
Virus Source ◽  
Simulated Field

SUMMARYExposure of weaned hamsters to an environment contaminated with LCM virus shed by tolerantly infected mice led to short subclinical infections. If infection occurred in early pregnancy, the young appeared normal at birth but their tissues were highly infective. For two to three months their bites and urine were also highly infective. A viraemia did not persist long enough for successive vertical transmissions of the infection to be likely. However, the viruria persisted in most prenatally infected hamsters for at least eight months and under simulated field conditions was a potent virus source for contact infections, leading to further generations of prenatally infected young. In the absence of the natural reservoir host, such long-term carriers could have been a major factor in causing the build-up of infection in colonies of hamsters which, when purchased as household pets, led to a recent spate of human clinical infections in Germany and the U.S.A.

scholarly journals Difluorodeoxyuridine plasma concentrations after low-dose gemcitabine during chemoradiation in head and neck cancer patients

2010 ◽  
Vol 68 (1) ◽  
pp. 185-191 ◽  
Author(s):  
P. Specenier ◽  
G. Guetens ◽  
J. Dyck ◽  
G. De Boeck ◽  
J. Weyler ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Head And Neck ◽  
Cancer Patients ◽  
Neck Cancer ◽  
Low Dose ◽  
Plasma Concentrations

scholarly journals Linking rattiness, geography and environmental degradation to spillover Leptospira infections in marginalised urban settings: an eco-epidemiological community-based cohort study in Brazil

2021 ◽  
Author(s):  
Max T Eyre ◽  
Fábio N Souza ◽  
Ticiana S. A. Carvalho-Pereira ◽  
Nivison Nery ◽  
Daiana de Oliveira ◽  
...  
Keyword(s):  
Public Health ◽  
Public Health Intervention ◽  
Spatial Modelling ◽  
The United States ◽  
Infection Risk ◽  
Human Infection ◽  
Global Public Health ◽  
Entire Study ◽  
Urban Settings ◽  
Public Health Burden

Background: Zoonotic spillover from animal reservoirs is responsible for a significant global public health burden, but the processes that promote spillover events are poorly understood in complex urban settings. Endemic transmission of Leptospira, the agent of leptospirosis, in marginalised urban communities occurs through human exposure to an environment contaminated by bacteria shed in the urine of the rat reservoir. However, it is unclear to what extent transmission is driven by variation in the distribution of rats or by the dispersal of bacteria in rainwater runoff and overflow from open sewer systems. <br /><br />Methods: We conducted an eco-epidemiological study in a high-risk community in Salvador, Brazil, by prospectively following a cohort of 1,401 residents to ascertain serological evidence for leptospiral infections. A concurrent rat ecology study was used to collect information on the fine-scale spatial distribution of ‘rattiness’, our proxy for rat abundance and exposure of interest. We developed and applied a novel geostatistical framework for joint spatial modelling of multiple indices of disease reservoir abundance and human infection risk. <br /><br />Results: The estimated infection rate was 51.4 (95\%CI 40.4, 64.2) infections per 1,000 follow-up events. Infection risk increased with age until 30 years of age and was associated with male gender. Rattiness was positively associated with infection risk for residents across the entire study area, but this effect was stronger in higher elevation areas (OR 3.27 95\%CI 1.68, 19.07) than in lower elevation areas (OR 1.14 95\%CI 1.05, 1.53). <br /><br />Conclusions: These findings suggest that, while frequent flooding events may disperse bacteria in regions of low elevation, environmental risk in higher elevation areas is more localised and directly driven by the distribution of local rat populations. The modelling framework developed may have broad applications in delineating complex animal-environment-human interactions during zoonotic spillover and identifying opportunities for public health intervention.<br /><br />Funding: This work was supported by the Oswaldo Cruz Foundation and Secretariat of Health Surveillance, Brazilian Ministry of Health, the National Institutes of Health of the United States (grant numbers F31 AI114245, R01 AI052473, U01 AI088752, R01 TW009504 and R25 TW009338); the Wellcome Trust (102330/Z/13/Z), and by the Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB/JCB0020/2016). M.T.E is supported by an MRC doctorate studentship. F.N.S. participated in this study under a FAPESB doctorate scholarship.

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