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Wang X, Mathias DK. Surveillance of ticks (Acari: Ixodidae) and tick-borne pathogens in Eastern Central Alabama. JOURNAL OF MEDICAL ENTOMOLOGY 2024; 61:1251-1260. [PMID: 39102892 DOI: 10.1093/jme/tjae096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/28/2024] [Accepted: 07/18/2024] [Indexed: 08/07/2024]
Abstract
Similar to other states in the southeastern United States, human cases of tick-borne diseases in Alabama have risen steadily over the last 2 decades. Nevertheless, limited data have been published on ticks or tick-borne pathogen (TBP) distributions since the 1990s. To better understand the risk of tick and TBP exposure in eastern central Alabama, ticks were sampled repeatedly across 8 sites associated with recreational use during May and June of 2015 to characterize tick density and diversity. Although habitats were similar across sites, tick density varied among locations. Seven species were collected, but 97.7% of 1,310 samples were the lone star tick, Amblyomma americanum (L.), the primary vector of ehrlichial agents and the tick species most commonly linked to alpha-gal syndrome and southern tick-associated rash illness. To investigate pathogen prevalence among sites, we tested A. americanum by a multiplex qPCR assay for 5 bacterial species, including 3 Ehrlichia spp. and 2 Rickettsia spp. None of the specimens tested positive for Panola Mountain Ehrlichia or Rickettsia parkeri. However, causative agents of human ehrlichiosis, Ehrlichia chaffeensis and Ehrlichia ewingii, occurred at half of the locations with, respectively, 0.27% and 0.45% of A. americanum infected on average. In contrast, Rickettsia amblyommatis, a tick endosymbiont suspected to be nonpathogenic, was found in 54.5% of the 1119 A. americanum tested. Despite low infection rates of Ehrlichia spp. in A. americanum, high encounter rates with this species in recreational deciduous woodlands suggest a moderate risk of tick bite and a low-to-moderate risk of TBP exposure in late spring.
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Affiliation(s)
- Xiaodi Wang
- Department of Entomology and Plant Pathology, 301 Funchess Hall, Auburn University, AL 36849, USA
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Derrick K Mathias
- Department of Entomology and Plant Pathology, 301 Funchess Hall, Auburn University, AL 36849, USA
- Florida Medical Entomology Laboratory, Department of Entomology and Nematology, University of Florida, Vero Beach, FL 32962, USA
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Iyamu O, Ciccone EJ, Schulz A, Sung J, Abernathy H, Alejo A, Tyrlik K, Arahirwa V, Mansour O, Giandomenico D, Diaz MM, Boyce RM. Neurological manifestations of ehrlichiosis among a cohort of patients: prevalence and clinical symptoms. BMC Infect Dis 2024; 24:701. [PMID: 39020279 PMCID: PMC11253485 DOI: 10.1186/s12879-024-09607-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 07/12/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND Ehrlichiosis is a potentially fatal tick-borne disease that can progress to involve the central nervous system (CNS) (i.e., neuro-ehrlichiosis), particularly in cases where diagnosis and treatment are delayed. Despite a six-fold national increase in the incidence of ehrlichiosis over the past 20 years, recent data on the prevalence and manifestations of neuro-ehrlichiosis are lacking. METHODS We conducted a retrospective chart review of all patients tested for ehrlichiosis at University of North Carolina Health facilities between 2018 and 2021 and identified patients who met epidemiological criteria for ehrlichiosis as established by the Council of State and Territorial Epidemiologists and employed by the Centers for Disease Control and Prevention. We estimated the prevalence of neurological symptoms and described the spectrum of neurological manifestations in acute ehrlichiosis, documenting select patient cases in more detail in a case series. RESULTS Out of 55 patients with confirmed or probable ehrlichiosis, five patients (9.1%) had neurologic symptoms, which is notably lower than previous estimates. Neurological presentations were highly variable and included confusion, amnesia, seizures, focal neurological deficits mimicking ischemic vascular events, and an isolated cranial nerve palsy, though all patients had unremarkable neuroimaging at time of presentation. All but one patient had risk factors for severe ehrlichiosis (i.e., older age, immunosuppression). CONCLUSIONS Neuro-ehrlichiosis may lack unifying patterns in clinical presentation that would otherwise aid in diagnosis. Clinicians should maintain a high index of suspicion for neuro-ehrlichiosis in patients with acute febrile illness, diverse neurological symptoms, and negative neuroimaging in lone star tick endemic regions.
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Affiliation(s)
- Osahon Iyamu
- College of Arts and Sciences, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
- Perelman School of Medicine, University of Pennsylvania, PA, 19104, Philadelphia, USA
| | - Emily J Ciccone
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Abigail Schulz
- College of Medicine, University of Illinois, IL, 61605, Peoria, USA
| | - Julia Sung
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Haley Abernathy
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Aidin Alejo
- School of Medicine, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Katherine Tyrlik
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Victor Arahirwa
- School of Medicine, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Odai Mansour
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Dana Giandomenico
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Monica M Diaz
- Department of Neurology, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA
| | - Ross M Boyce
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA.
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, 27599, Chapel Hill, USA.
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, 123 West Franklin Street, Suite 2151, NC, 27516, Chapel Hill, USA.
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Bhosale CR, Wilson KN, Ledger KJ, White ZS, Dorleans R, De Jesus CE, Wisely SM. Ticks and Tick-Borne Pathogens in Recreational Greenspaces in North Central Florida, USA. Microorganisms 2023; 11:756. [PMID: 36985329 PMCID: PMC10057063 DOI: 10.3390/microorganisms11030756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
Tick-borne infections are an increasing medical and veterinary concern in the southeastern United States, but there is limited understanding of how recreational greenspaces influence the hazard of pathogen transmission. This study aimed to estimate the potential human and companion animal encounter risk with different questing tick species, and the bacterial or protozoal agents they carry in recreational greenspaces. We collected ticks bimonthly along trails and designated recreational areas in 17 publicly accessible greenspaces, in and around Gainesville, Florida, USA. We collected Amblyomma americanum, Ixodes scapularis, Amblyomma maculatum, Dermacentor variabilis, Ixodes affinis, and Haemaphysalis leporispalustris. Across the six tick species collected, we detected 18 species of bacteria or protozoa within the Babesia, Borrelia, Cytauxzoon, Cryptoplasma (Allocryptoplasma), Ehrlichia, Hepatozoon, Rickettsia, and Theileria genera, including pathogens of medical or veterinary importance. While tick abundance and associated microorganism prevalence and richness were the greatest in natural habitats surrounded by forests, we found both ticks and pathogenic microorganisms in manicured groundcover. This relationship is important for public health and awareness, because it suggests that the probability of encountering an infected tick is measurable and substantial even on closely manicured turf or gravel, if the surrounding landcover is undeveloped. The presence of medically important ticks and pathogenic microorganisms in recreational greenspaces indicates that public education efforts regarding ticks and tick-borne diseases are warranted in this region of the United States.
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Affiliation(s)
- Chanakya R. Bhosale
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
- Dr. Kiran C. Patel College of Osteopathic Medicine, Nova Southeastern University, Fort Lauderdale, FL 33328, USA
| | - Kristen N. Wilson
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Kimberly J. Ledger
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Zoe S. White
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Rayann Dorleans
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Carrie E. De Jesus
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Samantha M. Wisely
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA
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Wood RR, Roberts RW, Kerr SM, Wasden M, Hammer TG, McCreadie JW, Rayner JO. Tick-Borne Pathogens Associated with Medically Important Ticks in Alabama: A Four-Year Survey. Vector Borne Zoonotic Dis 2023; 23:57-62. [PMID: 36576967 DOI: 10.1089/vbz.2022.0038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Background: Tick-borne diseases (TBDs) represent a significant threat to human health in the United States. Based on reported cases of notifiable TBDs to the Centers for Disease Control and Prevention (CDC) the state of Alabama is no exception, yet previously there has been no active surveillance program in place to comprehensively assess the presence and prevalence of tick vectors and their associated TBD pathogens in Alabama. Here we summarize initial findings from a 4-year survey to address this unmet need. Materials and Methods: Beginning in 2018 and proceeding through 2021, ticks were collected throughout the state of Alabama and pooled before being screened for a panel of TBD pathogens known to circulate in the United States. Results: Consistent with previously reported cases, TBD pathogens associated with anaplasmosis, babesiosis, ehrlichiosis, and spotted fever rickettsiosis were detected in ticks of Alabama. Causative agents for tularemia and Lyme disease were not detected despite previously reported human disease cases. There was also no evidence of Heartland virus despite recent reports of the virus being detected in ticks in Northwestern counties. Conclusions: While these results serve to provide some insights into TBD pathogens associated with ticks in Alabama, they also raise many questions that highlight the need for additional studies and continued surveillance to fully understand the TBD threat to human health in Alabama.
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Affiliation(s)
- Raphael Ryan Wood
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Rosemary W Roberts
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Skyler M Kerr
- Biology Department, College of Arts and Sciences, University of South Alabama, Mobile, Alabama, USA
| | - Madeline Wasden
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Thelma G Hammer
- Biology Department, College of Arts and Sciences, University of South Alabama, Mobile, Alabama, USA
| | - John W McCreadie
- Biology Department, College of Arts and Sciences, University of South Alabama, Mobile, Alabama, USA
| | - Jonathan O Rayner
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
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Pasternak AR, Palli SR. County-level surveillance for the lone star tick, Amblyomma americanum, and its associated pathogen, Ehrlichia chaffeensis, in Kentucky. Ticks Tick Borne Dis 2023; 14:102072. [PMID: 36379171 DOI: 10.1016/j.ttbdis.2022.102072] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 10/04/2022] [Accepted: 10/18/2022] [Indexed: 11/11/2022]
Abstract
Kentucky experiences some of the highest incidence rates for ehrlichiosis nationwide. Ehrlichiosis is a bacterial infection caused primarily by the pathogen Ehrlichia chaffeensis and can be transmitted to humans through the bite of an infected tick, notably Amblyomma americanum. Amblyomma americanum, the lone star tick, is common to Kentucky and much of the southeast, but has expanded farther north in recent years. As an abundant and aggressive nondiscriminatory biter, this species is of major public health concern for transmission of pathogens to humans. As this vector's range expands, surveillance remains a necessary tool providing data that allows researchers to track this expansion over time. The historical information on tick distribution in Kentucky is variable with very little data on a statewide scale. From January 2019 to December 2020, we conducted surveillance for A. americanum in Kentucky through field collections and the establishment of a statewide tick submission program with the help of the Kentucky Department for Public Health and screened for E. chaffeensis on a county-level throughout the state. We collected 5,726 A. americanum ticks in 77 counties and detected E. chaffeensis in 32 counties. The minimum infection rate was 1.8%. With the expansion of A. americanum and increasing cases of tick-borne diseases, future surveillance is needed to monitor this important tick vector over time.
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Affiliation(s)
- Anna R Pasternak
- Department of Entomology, University of Kentucky, Lexington, KY 40546, United States.
| | - Subba R Palli
- Department of Entomology, University of Kentucky, Lexington, KY 40546, United States
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Identification of Bacterial Communities and Tick-Borne Pathogens in Haemaphysalis spp. Collected from Shanghai, China. Trop Med Infect Dis 2022; 7:tropicalmed7120413. [PMID: 36548668 PMCID: PMC9787663 DOI: 10.3390/tropicalmed7120413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/30/2022] [Accepted: 11/30/2022] [Indexed: 12/04/2022] Open
Abstract
Ticks can carry and transmit a large number of pathogens, including bacteria, viruses and protozoa, posing a huge threat to human health and animal husbandry. Previous investigations have shown that the dominant species of ticks in Shanghai are Haemaphysalis flava and Haemaphysalis longicornis. However, no relevant investigations and research have been carried out in recent decades. Therefore, we investigated the bacterial communities and tick-borne pathogens (TBPs) in Haemaphysalis spp. from Shanghai, China. Ixodid ticks were collected from 18 sites in Shanghai, China, and identified using morphological and molecular methods. The V3-V4 hypervariable regions of the bacterial 16S rRNA gene were amplified from the pooled tick DNA samples and subject to metagenomic analysis. The microbial diversity in the tick samples was estimated using the alpha diversity that includes the observed species index and Shannon index. The Unifrac distance matrix as determined using the QIIME software was used for unweighted Unifrac Principal coordinates analysis (PCoA). Individual tick DNA samples were screened with genus-specific or group-specific nested polymerase chain reaction (PCR) for these TBPs and combined with a sequencing assay to confirm the results of the V3-V4 hypervariable regions of the bacterial 16S rRNA gene. We found H. flava and H. longicornis to be the dominant species of ticks in Shanghai in this study. Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria are the main bacterial communities of Haemaphysalis spp. The total species abundances of Proteobacteria, Firmicutes and Bacteroidetes, are 48.8%, 20.8% and 18.1%, respectively. At the level of genus analysis, H. longicornis and H. flava carried at least 946 genera of bacteria. The bacteria with high abundance include Lactobacillus, Coxiella, Rickettsia and Muribaculaceae. Additionally, Rickettsia rickettsii, Rickettsia japonica, Candidatus Rickettsia jingxinensis, Anaplasma bovis, Ehrlichia ewingii, Ehrlichia chaffeensis, Coxiella spp. and Coxiella-like endosymbiont were detected in Haemaphysalis spp. from Shanghai, China. This study is the first report of bacterial communities and the prevalence of some main pathogens in Haemaphysalis spp. from Shanghai, China, and may provide insights and evidence for bacterial communities and the prevalence of the main pathogen in ticks. This study also indicates that people and other animals in Shanghai, China, are exposed to several TBPs.
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Che Lah EF, George E, Apanaskevich D, Ahmad M, Yaakop S. First Record of the Tortoise Tick, Amblyomma geoemydae (Cantor, 1847) (Acari: Ixodidae) Parasitizing a Tree Shrew, Tupaia glis (Scandentia: Tupaiidae) in West Malaysia. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:1473-1478. [PMID: 35482611 DOI: 10.1093/jme/tjac042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Indexed: 06/14/2023]
Abstract
The tick genus Amblyomma Koch, 1844 (Acari: Ixodidae) has received little attention in Malaysia; therefore, its associated hosts and distribution records are poorly known. In this study, we collected six Amblyomma sp. individuals (two larvae and four adults) that infested a common treeshrew, Tupaia glis (Diard, 1820) (Scandentia: Tupaiidae) caught in a recreational area in Sungai Lembing, Pahang (West Malaysia). The adult female ticks were morphologically identified according to taxonomic keys prior to molecular identification using cytochrome oxidase subunit I (COI) and 16S rDNA genes. The ticks were genetically verified as Amblyomma geoemydae (Cantor, 1847) with 98%-99% similarity to the available GenBank sequences. Neighbor-joining (NJ) trees indicated that A. geoemydae was clearly distinguished from other Amblyomma ticks and this was supported with high bootstrap values. This paper is the first to report A. geoemydae ticks infesting T. glis and provides a new tick-host record from West Malaysia. This information is significant for further investigation, specifically on this tick species as potential vector of tick-borne disease (TBD) agents.
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Affiliation(s)
- Ernieenor Faraliana Che Lah
- Acarology Unit, Infectious Diseases Research Centre, Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, Jalan Setia Murni U13/52, Seksyen U13, Setia Alam, 40170, Shah Alam, Selangor, Malaysia
- Centre for Insect Systematics, Department of Biological Science and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Ernna George
- Acarology Unit, Infectious Diseases Research Centre, Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, Jalan Setia Murni U13/52, Seksyen U13, Setia Alam, 40170, Shah Alam, Selangor, Malaysia
| | - Dmitry Apanaskevich
- United States National Tick Collection, The James H. Oliver, Jr. Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA, 30460-8042, USA
- Zoological Institute, Russian Academy of Sciences, St. Petersburg, 199034, Russia
| | - Mariana Ahmad
- Acarology Unit, Infectious Diseases Research Centre, Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, Jalan Setia Murni U13/52, Seksyen U13, Setia Alam, 40170, Shah Alam, Selangor, Malaysia
| | - Salmah Yaakop
- Centre for Insect Systematics, Department of Biological Science and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
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Cerreta AJ, Yang TS, Ramsay EC, Birkenheuer AJ, Rahoi D, Qurollo B, Wilson J, Cushing AC. DETECTION OF VECTOR-BORNE INFECTIONS IN LIONS AND TIGERS AT TWO ZOOS IN TENNESSEE AND OKLAHOMA, USA. J Zoo Wildl Med 2022; 53:50-59. [PMID: 35339149 PMCID: PMC10685398 DOI: 10.1638/2020-0199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2021] [Indexed: 11/21/2022] Open
Abstract
Protozoal and bacterial vector-borne infections are frequently diagnosed in domestic felids. However, with the exception of Mycoplasma haemofelis and Cytauxzoon felis, their occurrence in managed nondomestic felids housed in the United States is largely unknown. Following a case in February 2020 of fulminant cytauxzoonosis in an African lion (Panthera leo), EDTA-whole blood samples were collected opportunistically from February 2020 through June 2020 from 34 adult tigers (Panthera tigris) and eight adult African lions from the same sanctuary in eastern Tennessee as well as 14 adult tigers from a zoo in southern Oklahoma. Samples were analyzed for Cytauxzoon felis, Bartonella spp., hemotropic Mycoplasma, Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp., and Hepatozoon spp. DNA by PCR amplification. All animals were asymptomatic at the time of collection. None of the Oklahoma animals were positive for vector-borne organisms, but these pathogens were detected in tigers at the Tennessee facility, including Cytauxzoon felis (11.8%), "Candidatus Mycoplasma haemominutum" (5.9%), and Ehrlichia ewingii (2.9%). During the study period, two animals developed clinical signs of cytauxzoonosis and were assessed for vector-borne infections as part of their diagnostic evaluation. This study documents the presence of tick-borne diseases in managed nondomestic felids in the southeastern United States and underscores that ectoparasite control measures should be practiced to minimize exposure of carnivores in managed care.
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Affiliation(s)
- Anthony J Cerreta
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA
| | - Tzushan S Yang
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
| | - Edward C Ramsay
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA
| | - Adam J Birkenheuer
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
| | - Dane Rahoi
- Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA
| | - Barbara Qurollo
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
| | - James Wilson
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
| | - Andrew C Cushing
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA,
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Eisen RJ, Paddock CD. Tick and Tickborne Pathogen Surveillance as a Public Health Tool in the United States. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:1490-1502. [PMID: 32440679 PMCID: PMC8905548 DOI: 10.1093/jme/tjaa087] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Indexed: 05/03/2023]
Abstract
In recent decades, tickborne disease (TBD) cases and established populations of medically important ticks have been reported over expanding geographic areas, and an increasing number of tickborne bacteria, viruses, and protozoans have been recognized as human pathogens, collectively contributing to an increasing burden of TBDs in the United States. The prevention and diagnosis of TBDs depend greatly on an accurate understanding by the public and healthcare providers of when and where persons are at risk for exposure to human-biting ticks and to the pathogens these ticks transmit. However, national maps showing the distributions of medically important ticks and the presence or prevalence of tickborne pathogens are often incomplete, outdated, or lacking entirely. Similar deficiencies exist regarding geographic variability in host-seeking tick abundance. Efforts to accurately depict acarological risk are hampered by lack of systematic and routine surveillance for medically important ticks and their associated human pathogens. In this review, we: 1) outline the public health importance of tick surveillance; 2) identify gaps in knowledge regarding the distributions and abundance of medically important ticks in the United States and the presence and prevalence of their associated pathogens; 3) describe key objectives for tick surveillance and review methods appropriate for addressing those goals; and 4) assess current capacity and barriers to implementation and sustainability of tick surveillance programs.
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Affiliation(s)
- Rebecca J. Eisen
- Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO
| | - Christopher D. Paddock
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA
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Farooq I, Moriarty TJ. The Impact of Tick-Borne Diseases on the Bone. Microorganisms 2021; 9:663. [PMID: 33806785 PMCID: PMC8005031 DOI: 10.3390/microorganisms9030663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 12/21/2022] Open
Abstract
Tick-borne infectious diseases can affect many tissues and organs including bone, one of the most multifunctional structures in the human body. There is a scarcity of data regarding the impact of tick-borne pathogens on bone. The aim of this review was to survey existing research literature on this topic. The search was performed using PubMed and Google Scholar search engines. From our search, we were able to find evidence of eight tick-borne diseases (Anaplasmosis, Ehrlichiosis, Babesiosis, Lyme disease, Bourbon virus disease, Colorado tick fever disease, Tick-borne encephalitis, and Crimean-Congo hemorrhagic fever) affecting the bone. Pathological bone effects most commonly associated with tick-borne infections were disruption of bone marrow function and bone loss. Most research to date on the effects of tick-borne pathogen infections on bone has been quite preliminary. Further investigation of this topic is warranted.
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Affiliation(s)
- Imran Farooq
- Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, Canada;
| | - Tara J. Moriarty
- Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, Canada;
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON M5G 1G6, Canada
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11
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Saleh MN, Allen KE, Lineberry MW, Little SE, Reichard MV. Ticks infesting dogs and cats in North America: Biology, geographic distribution, and pathogen transmission. Vet Parasitol 2021; 294:109392. [PMID: 33971481 PMCID: PMC9235321 DOI: 10.1016/j.vetpar.2021.109392] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/20/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022]
Abstract
A diverse array of ixodid and argasid ticks infest dogs and cats in North America, resulting in skin lesions, blood loss, and disease. The ticks most commonly found on pets in this region are hard ticks of the genera Amblyomma, Dermacentor, Ixodes, and Rhipicephalus, as well as the more recently established Haemaphysalis longicornis. Soft tick genera, especially Otobius and Ornithodoros, are also reported from pets in some regions. In this review, we provide a summary of the complex and diverse life histories, distinct morphologies, and questing and feeding behaviors of the more common ticks of dogs and cats in North America with a focus on recent changes in geographic distribution. We also review pathogens of dogs and cats associated with the different tick species, some of which can cause serious, potentially fatal disease, and describe the zoonotic risk posed by ticks of pets. Understanding the natural history of ticks and the maintenance cycles responsible for providing an ongoing source of tick-borne infections is critical to effectively combatting the challenges ticks pose to the health of pets and people.
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Affiliation(s)
- Meriam N Saleh
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, 74078, United States
| | - Kelly E Allen
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, 74078, United States.
| | - Megan W Lineberry
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, 74078, United States
| | - Susan E Little
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, 74078, United States
| | - Mason V Reichard
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, 74078, United States
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Kuriakose K, Pettit AC, Schmitz J, Moncayo A, Bloch KC. Assessment of Risk Factors and Outcomes of Severe Ehrlichiosis Infection. JAMA Netw Open 2020; 3:e2025577. [PMID: 33201233 PMCID: PMC7672514 DOI: 10.1001/jamanetworkopen.2020.25577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
IMPORTANCE Ehrlichiosis cases in the US have increased more than 8-fold since 2000. Up to 57% of patients with ehrlichiosis require hospitalization and 11% develop a life-threatening complication; however, risk factors for serious disease are not well documented. OBJECTIVE To examine risk factors associated with severe ehrlichiosis. DESIGN, SETTING, AND PARTICIPANTS An analytic cross-sectional study of patients diagnosed with ehrlichiosis by polymerase chain reaction (PCR) between January 1, 2007, and December 31, 2017, was conducted in a single tertiary-care center in a region endemic for ehrlichiosis. Analysis was performed from February 27, 2018, to September 9, 2020. A total of 407 positive Ehrlichia PCR results were identified from 383 unique patients, with 155 unique patients meeting study criteria. Patients hospitalized at other institutions who had a positive Ehrlichia PCR performed as a reference test (n = 222) were excluded as no clinical data were available. Electronic medical record review was performed to collect demographic, clinical, laboratory, treatment, and outcomes data. Cases were excluded when there were insufficient clinical data to assess the severity of illness (n = 3) and when the clinical illness did not meet the case definition for ehrlichiosis (n = 3). EXPOSURES Date of presentation, onset of symptoms, date of PCR testing, date of treatment initiation, site of care, age, birth sex, race/ethnicity, Charlson Comorbidity Index, trimethoprim with sulfamethoxazole use within the prior 2 weeks, and immunosuppression. MAIN OUTCOMES AND MEASURES Requirement for intensive care unit (ICU) admission. RESULTS Of the 155 patients who met inclusion criteria, 99 patients (63.9%) were men, and 145 patients (93.5%) identified as non-Hispanic White; median age was 50 years (interquartile range, 23-64 years). Intensive care unit admission was indicated in 43 patients (27.7%), 94 patients (60.6%) were hospitalized on general medical floors, and 18 patients (11.6%) received care as outpatients. In adjusted analysis, time to treatment initiation was independently associated with an increased risk for ICU admission (adjusted prevalence ratio [aPR], 1.09; 95% CI, 1.04-1.14; P < .001). Documentation of tick exposure was independently associated with a decreased risk for ICU admission (aPR, 0.54; 95% CI, 0.34-0.86; P = .01). There appeared to be a nonsignificant change toward a decreased need for ICU care among immunosuppressed persons (aPR, 0.51; 95% CI, 0.26-1.00; P = .05). CONCLUSIONS AND RELEVANCE This study suggests that delay in initiation of doxycycline therapy is a significant factor associated with severe ehrlichiosis. Increased recognition of infection by front-line clinicians to promote early treatment may improve outcomes associated with this increasingly common and life-threatening infection.
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Affiliation(s)
- Kevin Kuriakose
- Section of Infectious Disease, Renown Health, Reno, Nevada
- Department of Medicine, School of Medicine, University of Nevada, Reno
| | - April C. Pettit
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jonathan Schmitz
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Abelardo Moncayo
- Vector-Borne Disease Section, Tennessee Department of Health, Nashville
- Department of Health Policy, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Karen C. Bloch
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Health Policy, Vanderbilt University Medical Center, Nashville, Tennessee
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Gettings JR, Self SCW, McMahan CS, Brown DA, Nordone SK, Yabsley MJ. Local and regional temporal trends (2013-2019) of canine Ehrlichia spp. seroprevalence in the USA. Parasit Vectors 2020; 13:153. [PMID: 32228712 PMCID: PMC7106614 DOI: 10.1186/s13071-020-04022-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/16/2020] [Indexed: 11/28/2022] Open
Abstract
Background In the USA, there are several Ehrlichia spp. of concern including Ehrlichia canis, Ehrlichia ewingii, Ehrlichia chaffeensis, Ehrlichia muris eauclarensis, and “Panola Mountain Ehrlichia”. Of these, E. canis is considered the most clinically relevant for domestic dogs, with infection capable of causing acute, subclinical, and chronic stages of disease. Changes in climate, land use, habitats, and wildlife reservoir populations, and increasing contact between both human and dog populations with natural areas have resulted in the increased risk of vector-borne disease throughout the world. Methods A Bayesian spatio-temporal binomial regression model was applied to serological test results collected from veterinarians throughout the contiguous USA between January 2013 and November 2019. The model was used to quantify both regional and local temporal trends of canine Ehrlichia spp. seroprevalence and identify areas that experienced significant increases in seroprevalence. Results Regionally, increasing seroprevalence occurred within several states throughout the central and southeastern states, including Missouri, Arkansas, Mississippi, Alabama, Virginia, North Carolina, Georgia and Texas. The underlying local trends revealed increasing seroprevalence at a finer scale. Clusters of locally increasing seroprevalence were seen from the western Appalachian region into the southern Midwest, along the Atlantic coast in New England, parts of Florida, Illinois, Wisconsin and Minnesota, and in a couple areas of the Mountain region. Clusters of locally decreasing seroprevalence were seen throughout the USA including New York and the mid-Atlantic states, Texas, the Midwest, and California. Conclusions Canine Ehrlichia spp. seroprevalence is increasing in both endemic and non-endemic areas of the USA. The findings from this study indicate that dogs across a wide area of the USA are at risk of exposure and these results should provide veterinarians and pet owners with the information they need to make informed decisions about prevention of tick exposure.![]()
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Affiliation(s)
- Jenna R Gettings
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, 30602, USA.
| | - Stella C W Self
- Arnold School of Public Health, University of South Carolina, Columbia, 29208, USA
| | - Christopher S McMahan
- School of Mathematical and Statistical Sciences, Clemson University, Clemson, 29634, USA
| | - D Andrew Brown
- School of Mathematical and Statistical Sciences, Clemson University, Clemson, 29634, USA
| | - Shila K Nordone
- Comparative Medicine Institute, North Carolina State University College of Veterinary Medicine, Raleigh, 27607, USA
| | - Michael J Yabsley
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, 30602, USA.,Warnell School of Forestry and Natural Resources, University of Georgia, Athens, 30602, USA
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Trout Fryxell RT, Vogt JT. Collaborative-Tick Surveillance Works: An Academic and Government Partnership for Tick Surveillance in the Southeastern United States (Acari: Ixodidae). JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1411-1419. [PMID: 31049584 DOI: 10.1093/jme/tjz055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Indexed: 06/09/2023]
Abstract
Tick surveillance provides essential information on distributions and encounter frequencies; it is a component of operational activities in public health practice. Our research objectives were a proof-of-concept for collaborative surveillance, which involved establishing an academic and government partnership to enhance tick surveillance efforts. The University of Tennessee (UT) collaborated with United States Department of Agriculture Forest Service, Southern Research Station Forest Inventory Analysis (FIA) in an Occupational Health and Safety partnership. UT provided FIA crews in the southeastern United States with vials containing 80% ethanol (July 2014-November 2017). Crew members were instructed to put all encountered ticks into the vials and return them to FIA headquarters. UT identified all submitted ticks to species and life stage, and screened Amblyomma americanum (L.) for Ehrlichia bacteria using a nested-PCR assay. From the 198 returned vials, 1,180 ticks were submitted, including A. americanum (90.51%; 202 larvae, 503 nymphs, and 363 adults), Dermacentor variabilis Say (7.12%; 1 nymph, 83 adults), Ixodes scapularis (Say) (1.61%; 19 adults), Amblyomma maculatum Koch (0.59%; 1 nymph, 6 adults), and Amblyomma cajennense (Fabricius) (0.17%; 1 nymph, 1 adult). FIA crews encountered A. americanum with Ehrlichia and collection information was used to generate baseline occurrence data of tick encounters. Results indicate that this collaborative-tick surveillance can be improved and used to generate useful data including pathogen detection, and because crews revisit these sites, changes in tick encounters can be monitored.
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Affiliation(s)
- R T Trout Fryxell
- Department of Entomology and Plant Pathology, Plant Biotechnology Building, University of Tennessee, Knoxville, TN )
| | - J T Vogt
- United States Department of Agriculture Forest Service, Southern Research Station - Insects, Diseases, and Invasive Plants in Southern Forests, Athens, GA
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Amblyomma americanum serpin 27 (AAS27) is a tick salivary anti-inflammatory protein secreted into the host during feeding. PLoS Negl Trop Dis 2019; 13:e0007660. [PMID: 31449524 PMCID: PMC6730956 DOI: 10.1371/journal.pntd.0007660] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/06/2019] [Accepted: 07/24/2019] [Indexed: 11/20/2022] Open
Abstract
Ticks successfully feed and transmit pathogens by injecting pharmacological compounds in saliva to thwart host defenses. We have previously used LC-MS/MS to identify proteins that are present in saliva of unfed Amblyomma americanum ticks that were exposed to different hosts. Here we show that A. americanum serine protease inhibitor (serpin) 27 (AAS27) is an immunogenic saliva protein that is injected into the host within the first day of tick feeding and is an anti-inflammatory protein that might act by blocking plasmin and trypsin functions. Although AAS27 is injected into the host throughout tick feeding, qRT-PCR and western blotting analyses indicate that the respective transcript and protein are present in high amounts within the first 24 h of tick feeding. Biochemical screening of Pichia pastoris-expressed recombinant (r) AAS27 against mammalian proteases related to host defense shows it is an inhibitor of trypsin and plasmin, with stoichiometry of inhibition indices of 3.5 and 3.8, respectively. Consistent with typical inhibitory serpins, rAAS27 formed heat- and SDS-stable irreversible complexes with both proteases. We further demonstrate that rAAS27 inhibits trypsin with ka of 6.46 ± 1.24 x 104 M-1 s-1, comparable to serpins of other tick species. We show that native AAS27 is part of the repertoire of proteins responsible for the inhibitory activity against trypsin in crude tick saliva. AAS27 is likely utilized by the tick to evade the hosts inflammation defense since rAAS27 blocks both formalin and compound 48/80-induced inflammation in rats. Tick immune sera of rabbits that had acquired resistance against tick feeding following repeated infestations with A. americanum or Ixodes scapularis ticks reacts with rAAS27. Of significant interest, antibody to rAAS27 blocks this serpin inhibitory functions. Taken together, we conclude that AAS27 is an anti-inflammatory protein secreted into the host during feeding and may represent a potential candidate for development of an anti-tick vaccine.
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Frequent Prescribed Fires Can Reduce Risk of Tick-borne Diseases. Sci Rep 2019; 9:9974. [PMID: 31292479 PMCID: PMC6620321 DOI: 10.1038/s41598-019-46377-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 06/27/2019] [Indexed: 01/22/2023] Open
Abstract
Recently, a two-year study found that long-term prescribed fire significantly reduced tick abundance at sites with varying burn regimes (burned surrounded by burned areas [BB], burned surrounded by unburned areas [BUB], and unburned surrounded by burned areas [UBB]). In the current study, these ticks were tested for pathogens to more directly investigate the impacts of long-term prescribed burning on human disease risk. A total of 5,103 ticks (4,607 Amblyomma americanum, 76 Amblyomma maculatum, 383 Ixodes scapularis, two Ixodes brunneus, and 35 Dermacentor variabilis) were tested for Borrelia spp., Rickettsia spp., Ehrlichia spp., and Anaplasma phagocytophilum. Long-term prescribed fire did not significantly impact pathogen prevalence except that A. americanum from burned habitats had significantly lower prevalence of Rickettsia (8.7% and 4.6% for BUB and UBB sites, respectively) compared to ticks from control sites (unburned, surrounded by unburned [UBUB])(14.6%). However, during the warm season (spring/summer), encounter rates with ticks infected with pathogenic bacteria was significantly lower (98%) at burned sites than at UBUB sites. Thus, despite there being no differences in pathogen prevalence between burned and UBUB sites, risk of pathogen transmission is lower at sites subjected to long-term burning due to lower encounter rates with infected ticks.
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Trout Fryxell RT, Hendricks BM, Pompo K, Mays SE, Paulsen DJ, Operario DJ, Houston AE. Investigating the Adult Ixodid Tick Populations and Their Associated Anaplasma, Ehrlichia, and Rickettsia Bacteria at a Rocky Mountain Spotted Fever Hotspot in Western Tennessee. Vector Borne Zoonotic Dis 2017; 17:527-538. [PMID: 28598270 DOI: 10.1089/vbz.2016.2091] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ehrlichiosis and rickettsiosis are two common bacterial tick-borne diseases in the southeastern United States. Ehrlichiosis is caused by ehrlichiae transmitted by Amblyomma americanum and rickettsiosis is caused by rickettsiae transmitted by Amblyomma maculatum and Dermacentor variabilis. These ticks are common and have overlapping distributions in the region. The objective of this study was to identify Anaplasma, Ehrlichia, and Rickettsia species associated with questing ticks in a Rocky Mountain spotted fever (RMSF) hotspot, and identify habitats, time periods, and collection methods for collecting questing-infected ticks. Using vegetation drags and CO2-baited traps, ticks were collected six times (May-September 2012) from 100 sites (upland deciduous, bottomland deciduous, grassland, and coniferous habitats) in western Tennessee. Adult collections were screened for Anaplasma and Ehrlichia (simultaneous polymerase chain reaction [PCR]) and Rickettsia using genus-specific PCRs, and resulting positive amplicons were sequenced. Anaplasma and Ehrlichia were only identified within A. americanum (Ehrlichia ewingii, Ehrlichia chaffeensis, Panola Mountain Ehrlichia, and Anaplasma odocoilei sp. nov.); more Ehrlichia-infected A. americanum were collected at the end of June regardless of habitat and collection method. Rickettsia was identified in three tick species; "Candidatus Rickettsia amblyommii" from A. americanum, R. parkeri and R. andeanae from A. maculatum, and R. montanensis ( = montana) from D. variabilis. Overall, significantly more Rickettsia-infected ticks were identified as A. americanum and A. maculatum compared to D. variabilis; more infected-ticks were collected from sites May-July and with dragging. In this study, we report in the Tennessee RMSF hotspot the following: (1) Anaplasma and Ehrlichia are only found in A. americanum, (2) each tick species has its own Rickettsia species, (3) a majority of questing-infected ticks are collected May-July, (4) A. americanum and A. maculatum harbor pathogenic bacteria in western Tennessee, and (5) R. rickettsii remains unidentified.
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Affiliation(s)
- Rebecca T Trout Fryxell
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Brain M Hendricks
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Kimberly Pompo
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Sarah E Mays
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Dave J Paulsen
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Darwin J Operario
- 2 Division of Infectious Diseases and International Health, University of Virginia Health System , Charlottesville, Virginia
| | - Allan E Houston
- 3 Department of Forestry, Wildlife and Fisheries, University of Tennessee , Knoxville, Tennessee
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Allerdice MEJ, Hecht JA, Karpathy SE, Paddock CD. Evaluation of Gulf Coast Ticks (Acari: Ixodidae) for Ehrlichia and Anaplasma Species. JOURNAL OF MEDICAL ENTOMOLOGY 2017; 54:481-484. [PMID: 28031351 PMCID: PMC11063997 DOI: 10.1093/jme/tjw176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/25/2016] [Indexed: 06/06/2023]
Abstract
Amblyomma maculatum Koch (the Gulf Coast tick) is an aggressive, human-biting ixodid tick distributed throughout much of the southeastern United States and is the primary vector for Rickettsia parkeri, an emerging human pathogen. Amblyomma maculatum has diverse host preferences that include white-tailed deer, a known reservoir for Ehrlichia and Anaplasma species, including the human pathogens E. ewingii and E. chaffeensis. To examine more closely the potential role of A. maculatum in the maintenance of various pathogenic Ehrlichia and Anaplasma species, we screened DNA samples from 493 questing adult A. maculatum collected from six U.S. states using broad-range Anaplasmataceae and Ehrlichia genus-specific PCR assays. Of the samples tested, four (0.8%) were positive for DNA of Ehrlichia ewingii, one (0.2%) was positive for Anaplasma platys, and one (0.2%) was positive for a previously unreported Ehrlichia species closely related to Ehrlichia muris and an uncultivated Ehrlichia species from Haemaphysalis longicornis ticks in Japan. No ticks contained DNA of Ehrlichia chaffeensis, Ehrlichia canis, the Panola Mountain Ehrlichia, or Anaplasma phagocytophilum. This is the first identification of E. ewingii, A. platys, and the novel Ehrlichia in questing Gulf Coast ticks; nonetheless the low prevalence of these agents suggests that A. maculatum is not likely an important vector of these zoonotic pathogens.
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Affiliation(s)
- Michelle E J Allerdice
- Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, Atlanta, GA 30329 (; ; ; )
| | - Joy A Hecht
- Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, Atlanta, GA 30329 (; ; ; )
| | - Sandor E Karpathy
- Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, Atlanta, GA 30329 (; ; ; )
| | - Christopher D Paddock
- Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, Atlanta, GA 30329 (; ; ; )
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Sayler K, Rowland J, Boyce C, Weeks E. Borrelia burgdorferi DNA absent, multiple Rickettsia spp. DNA present in ticks collected from a teaching forest in North Central Florida. Ticks Tick Borne Dis 2016; 8:53-59. [PMID: 27720381 DOI: 10.1016/j.ttbdis.2016.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 01/10/2023]
Abstract
Tick-borne diseases are an emerging public health threat in the United States. In Florida, there has been public attention directed towards the possibility of locally acquired Borrelia burgdorferi sensu stricto, the causative agent of Lyme disease, in association with the lone star tick. The aim of this study was to determine the prevalence of ticks and the pathogens they carry and potentially transmit, such as B. burgdorferi, in a highly utilized teaching and research forest in North Central Florida. Ticks were collected by dragging and flagging methods over a four month period in early 2014, identified, and tested by PCR for multiple pathogens including Anaplasma, Borrelia, Rickettsia, and Ehrlichia species. During the study period the following ticks were collected: 2506 (96.5%) Amblyomma americanum L., 64 (2.5%) Ixodes scapularis Say, 19 (0.7%) Dermacentor variabilis Say, and 5 (0.2%) Ixodes affinis Neuman. Neither Borrelia spp. (0/846) nor Anaplasma spp. (0/69; Ixodes spp. only) were detected by PCR in any of the ticks tested. However, Rickettsia DNA was present in 53.7% (86/160), 62.5% (40/64), 60.0% (3/5) and 31.6% (6/19) of A. americanum, I. scapularis, I. affinis and D. variabilis, respectively. Furthermore, E. chaffeensis and E. ewingii DNA were detected in 1.3% and 4.4% of adult A. americanum specimens tested, respectively. Although receiving an A. americanum bite is likely in wooded areas in North Central Florida due to the abundance of this tick, the risk of contracting a tick-borne pathogen in this specific area during the spring season appears to be low. The potential for pathogen prevalence to be highly variable exists, even within a single geographical site and longitudinal studies are needed to assess how tick-borne pathogen prevalence is changing over time in North Central Florida.
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Affiliation(s)
- Katherine Sayler
- College of Veterinary Medicine, 2015 SW 16th Avenue, Veterinary Academic Building, University of Florida, Gainesville, FL, 32611, USA
| | - Jessica Rowland
- Department of Entomology and Nematology, PO Box 110620, 1881 Natural Area Drive, University of Florida, Gainesville, FL, 32611, USA; Emerging Pathogens Institute, 2055 Mowry Rd, University of Florida, Gainesville, FL, 32611, USA
| | - Carisa Boyce
- College of Veterinary Medicine, 2015 SW 16th Avenue, Veterinary Academic Building, University of Florida, Gainesville, FL, 32611, USA; Department of Entomology and Nematology, PO Box 110620, 1881 Natural Area Drive, University of Florida, Gainesville, FL, 32611, USA
| | - Emma Weeks
- Department of Entomology and Nematology, PO Box 110620, 1881 Natural Area Drive, University of Florida, Gainesville, FL, 32611, USA.
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Sayler KA, Loftis AD, Beatty SK, Boyce CL, Garrison E, Clemons B, Cunningham M, Alleman AR, Barbet AF. Prevalence of Tick-Borne Pathogens in Host-Seeking Amblyomma americanum (Acari: Ixodidae) and Odocoileus virginianus (Artiodactyla: Cervidae) in Florida. JOURNAL OF MEDICAL ENTOMOLOGY 2016; 53:949-956. [PMID: 27117680 DOI: 10.1093/jme/tjw054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/27/2016] [Indexed: 06/05/2023]
Abstract
Amblyomma americanum (L.), the lone star tick, is an aggressive tick that is expanding its geographic range within the United States. This tick is the vector for the human and veterinary pathogens Ehrlichia chaffeensis and Ehrlichia ewingii and is associated with other microbes of unspecified pathogenicity including Rickettsia amblyommii, Panola Mountain Ehrlichia, and Borrelia lonestari In Florida, there has been sparse contemporary data on the prevalence of these organisms in host-seeking lone star ticks. To determine the prevalence of this tick and associated microbes in North Central Florida state parks, ∼1,500 lone star tick specimens were collected between 2010 and 2012 analyzed by polymerase chain reaction (PCR) sequencing. Additionally, 393 white-tailed deer, Odocoileus virginianus (Zimmerman), samples were analyzed for pathogen prevalence using molecular methods and serology. In lone star ticks, 14.6, 15.6, and 57.1% were positive for E. chaffeensis, E. ewingii, and Rickettsia spp. DNA, respectively. Panola Mountain Ehrlichia or B. lonestari DNA were each detected in nearly 2% of tick specimens. In white-tailed deer, 7.3% were PCR positive for E. chaffeensis, 6.0% for E. ewingii, and 3.2% for rickettsial species. Approximately 45% of white-tailed deer specimens had antibodies to Ehrlichia spp., and <1% had antibodies to Borrelia burgdorferi In summary, E. chaffeensis, E. ewingii, and spotted fever group rickettsia are highly prevalent in host-seeking lone star ticks and in white-tailed deer in Florida. The molecular and serological evidence of these microbes underscore their zoonotic potential in this region.
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Affiliation(s)
- Katherine A Sayler
- Department of Physiological Sciences, University of Florida College of Veterinary Medicine, 2015 SW 16th Ave., Gainesville, FL 32608 (; ; ; ),
- Department of Infectious Disease and Pathology, University of Florida College of Veterinary Medicine, 2015 SW 16th Ave., Gainesville, FL 32608
| | - Amanda D Loftis
- Department of Microbiology, Midwestern University Glendale, 19555 N 59th Ave., Glendale, AZ 85308 , and
| | - Sarah K Beatty
- Department of Physiological Sciences, University of Florida College of Veterinary Medicine, 2015 SW 16th Ave., Gainesville, FL 32608 (; ; ; )
| | - Carisa L Boyce
- Department of Physiological Sciences, University of Florida College of Veterinary Medicine, 2015 SW 16th Ave., Gainesville, FL 32608 (; ; ; )
| | - Elina Garrison
- Florida Fish and Wildlife Conservation Commission, Fish & Wildlife Research Institute, 1105 SW Williston Rd., Gainesville, FL 32601 (; ; )
| | - Bambi Clemons
- Florida Fish and Wildlife Conservation Commission, Fish & Wildlife Research Institute, 1105 SW Williston Rd., Gainesville, FL 32601 (; ; )
| | - Mark Cunningham
- Florida Fish and Wildlife Conservation Commission, Fish & Wildlife Research Institute, 1105 SW Williston Rd., Gainesville, FL 32601 (; ; )
| | - Arthur R Alleman
- Department of Physiological Sciences, University of Florida College of Veterinary Medicine, 2015 SW 16th Ave., Gainesville, FL 32608 (; ; ; )
| | - Anthony F Barbet
- Department of Infectious Disease and Pathology, University of Florida College of Veterinary Medicine, 2015 SW 16th Ave., Gainesville, FL 32608
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Killmaster LF, Levin ML. Isolation and Short-Term Persistence of Ehrlichia ewingii in Cell Culture. Vector Borne Zoonotic Dis 2016; 16:445-8. [PMID: 27228133 DOI: 10.1089/vbz.2015.1938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ehrlichia ewingii is the causative agent of human and canine granulocytic ehrlichiosis. Since its discovery in 1970, little work has been done to characterize the pathogen or study the transmission dynamics due to the inability to grow the agent in vitro. The aim of this study was to assess the suitability of multiple cell lines and media formulations for propagation of E. ewingii in cell culture. In this study, we present an overview of attempts to isolate E. ewingii from the buffy coat of goats naturally infected by Amblyomma americanum ticks, as well as a methodology for maintaining the pathogen for up to 16 weeks in culture. The most promising results were seen with HL-60 cells differentiated by the addition of 1.5% DMSO to the media and supplemented with 8 mM l-glutamine. Cultures were passaged multiple times, and fluorescence and morulae were observed by indirect fluorescent antibody test and Diff-Quik staining. It is our hope that this information will provide a foundation for future attempts to propagate and maintain E. ewingii in cell culture.
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Affiliation(s)
- Lindsay F Killmaster
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention , U.S. Department of Health and Human Services, Atlanta, Georgia
| | - Michael L Levin
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention , U.S. Department of Health and Human Services, Atlanta, Georgia
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22
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Nelder MP, Russell CB, Sheehan NJ, Sander B, Moore S, Li Y, Johnson S, Patel SN, Sider D. Human pathogens associated with the blacklegged tick Ixodes scapularis: a systematic review. Parasit Vectors 2016; 9:265. [PMID: 27151067 PMCID: PMC4857413 DOI: 10.1186/s13071-016-1529-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/21/2016] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The blacklegged tick Ixodes scapularis transmits Borrelia burgdorferi (sensu stricto) in eastern North America; however, the agent of Lyme disease is not the sole pathogen harbored by the blacklegged tick. The blacklegged tick is expanding its range into areas of southern Canada such as Ontario, an area where exposure to blacklegged tick bites and tick-borne pathogens is increasing. We performed a systematic review to evaluate the public health risks posed by expanding blacklegged tick populations and their associated pathogens. METHODS We followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for conducting our systematic review. We searched Ovid MEDLINE, Embase, BIOSIS, Scopus and Environment Complete databases for studies published from 2000 through 2015, using subject headings and keywords that included "Ixodes scapularis", "Rickettsia", "Borrelia", "Anaplasma", "Babesia" and "pathogen." Two reviewers screened titles and abstracts against eligibility criteria (i.e. studies that included field-collected blacklegged ticks and studies that did not focus solely on B. burgdorferi) and performed quality assessments on eligible studies. RESULTS Seventy-eight studies were included in the final review, 72 were from the US and eight were from Canada (two studies included blacklegged ticks from both countries). Sixty-four (82%) studies met ≥ 75% of the quality assessment criteria. Blacklegged ticks harbored 91 distinct taxa, 16 of these are tick-transmitted human pathogens, including species of Anaplasma, Babesia, Bartonella, Borrelia, Ehrlichia, Rickettsia, Theileria and Flavivirus. Organism richness was highest in the Northeast (Connecticut, New York) and Upper Midwest US (Wisconsin); however, organism richness was dependent on sampling effort. The primary tick-borne pathogens of public health concern in Ontario, due to the geographic proximity or historical detection in Ontario, are Anaplasma phagocytophilum, Babesia microti, B. burgdorferi, Borrelia miyamotoi, deer tick virus and Ehrlichia muris-like sp. Aside from B. burgdorferi and to a much lesser concern A. phagocytophilum, these pathogens are not immediate concerns to public health in Ontario; rather they represent future threats as the distribution of vectors and pathogens continue to proliferate. CONCLUSIONS Our review is the first systematic assessment of the literature on the human pathogens associated with the blacklegged tick. As Lyme disease awareness continues to increase, it is an opportune time to document the full spectrum of human pathogens transmittable by blacklegged ticks.
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Affiliation(s)
- Mark P Nelder
- Enteric, Zoonotic and Vector-borne Diseases; Communicable Diseases, Emergency Preparedness and Response; Public Health Ontario, Toronto, Ontario, Canada.
| | - Curtis B Russell
- Enteric, Zoonotic and Vector-borne Diseases; Communicable Diseases, Emergency Preparedness and Response; Public Health Ontario, Toronto, Ontario, Canada
| | - Nina Jain Sheehan
- Enteric, Zoonotic and Vector-borne Diseases; Communicable Diseases, Emergency Preparedness and Response; Public Health Ontario, Toronto, Ontario, Canada
| | - Beate Sander
- Enteric, Zoonotic and Vector-borne Diseases; Communicable Diseases, Emergency Preparedness and Response; Public Health Ontario, Toronto, Ontario, Canada
- Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
- Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
| | - Stephen Moore
- Enteric, Zoonotic and Vector-borne Diseases; Communicable Diseases, Emergency Preparedness and Response; Public Health Ontario, Toronto, Ontario, Canada
| | - Ye Li
- Analytic Services, Knowledge Services, Public Health Ontario, Toronto, ON, Canada
| | - Steven Johnson
- Analytic Services, Knowledge Services, Public Health Ontario, Toronto, ON, Canada
| | - Samir N Patel
- Public Health Ontario Laboratories, Public Health Ontario, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Doug Sider
- Enteric, Zoonotic and Vector-borne Diseases; Communicable Diseases, Emergency Preparedness and Response; Public Health Ontario, Toronto, Ontario, Canada
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
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Maegli A, Loy JD, Cortinas R. Note on Ehrlichia chaffeensis, Ehrlichia ewingii, and “Borrelia lonestari” infection in lone star ticks (Acari: Ixodidae), Nebraska, USA. Ticks Tick Borne Dis 2016; 7:154-158. [DOI: 10.1016/j.ttbdis.2015.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/22/2015] [Accepted: 10/14/2015] [Indexed: 11/30/2022]
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Pompo K, Mays S, Wesselman C, Paulsen DJ, Fryxell RTT. Survey of Ticks Collected from Tennessee Cattle and Their Pastures for Anaplasma and Ehrlichia Species. J Parasitol 2016; 102:54-9. [DOI: 10.1645/15-814] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- K. Pompo
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - S. Mays
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - C. Wesselman
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - D. J. Paulsen
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - R. T. Trout Fryxell
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
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The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum). PLoS One 2016; 11:e0146651. [PMID: 26751816 PMCID: PMC4709196 DOI: 10.1371/journal.pone.0146651] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/21/2015] [Indexed: 11/19/2022] Open
Abstract
The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.
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Kho KL, Koh FX, Tay ST. Molecular evidence of potential novel spotted fever group rickettsiae, Anaplasma and Ehrlichia species in Amblyomma ticks parasitizing wild snakes. Parasit Vectors 2015; 8:112. [PMID: 25889376 PMCID: PMC4342797 DOI: 10.1186/s13071-015-0719-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 02/05/2015] [Indexed: 11/28/2022] Open
Abstract
Background Amblyomma ticks parasitize a wide range of animals in tropical regions. This study describes the identification of Amblyomma ticks from wild snakes in Malaysia and the detection of potential human pathogens such as Rickettsia, Anaplasma, Ehrlichia and bartonellae in the ticks. Findings Twenty one adult ticks (twelve A. varanense and nine Amblyomma helvolum ticks) identified from seven Python molurus snakes in Sepang and a pool of six A. helvolum ticks from a Naja sumatrana snake in Johore, Malaysia were investigated in this study. Amplification of the citrate synthase (gltA), 190-kDa surface antigen gene (ompA), 135-kDa surface antigen (ompB) and surface cell antigen (sca4) genes followed by sequence analysis confirmed the presence of two potential novel spotted fever group rickettsiae in the ticks. Candidatus Rickettsia sepangensis from an engorged A. varanense tick demonstrated high sequence similarity to Rickettsia tamurae; while Candidatus Rickettsia johorensis from two samples (individual and pooled) of A. helvolum and two A. varanense ticks were closely related to Rickettsia raoultii. Anaplasma and Ehrlichia DNA were detected from seven and two ticks, respectively. No bartonellae was detected from any of the ticks. Conclusion The finding in this study suggests that Amblyomma ticks parasitizing wild snakes may serve as reservoir hosts and carriers for rickettsioses, anaplasmosis and ehrlichiosis in this region.
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Affiliation(s)
- Kai Ling Kho
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
| | - Fui Xian Koh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
| | - Sun Tee Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
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Harmon JR, Scott MC, Baker EM, Jones CJ, Hickling GJ. Molecular identification of Ehrlichia species and host bloodmeal source in Amblyomma americanum L. from two locations in Tennessee, United States. Ticks Tick Borne Dis 2015; 6:246-52. [PMID: 25682494 DOI: 10.1016/j.ttbdis.2015.01.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 11/26/2022]
Abstract
The current status of tick-borne diseases in the southeastern United States is challenging to define due to emerging pathogens, uncertain tick/host relationships, and changing disease case definitions. A golf-oriented retirement community on the Cumberland Plateau in Tennessee experienced an ehrlichiosis outbreak in 1993, prompting efforts to reduce the local tick population using '4-Poster' acaricide devices targeting white-tailed deer (Odocoileus virginianus). In 2009, the prevalence of Ehrlichia spp. in questing ticks was surveyed in the area and compared to a Tennessee state park where acaricide had not been applied. The range of wildlife hosts that immature Amblyomma americanum fed upon and the role that these hosts may play in pathogen dynamics were investigated using a reverse line blot (RLB) bloodmeal analysis technique. Amblyomma americanum was by far the most common tick species in both study areas (>99% of ticks collected). Of 303 adult and nymphal A. americanum tested at the retirement community, six were positive for Ehrlichia chaffeensis (2.0%), 16 were positive for E. ewingii (5.3%), and six were positive for Panola Mountain Ehrlichia (2.0%). This is the first confirmation of Panola Mountain Ehrlichia in A. americanum from the state of Tennessee. The 9.3% prevalence of Ehrlichia spp. in ticks from the retirement community was similar to that detected at the state park site (5.5%), suggesting that the 4-Poster treatment had not been sufficient to reduce Ehrlichia spp. cycling in the tick population. At both study sites, A. americanum fed on a wide range of mammal and bird species, with a minority of detectable bloodmeals coming from deer. Of the Ehrlichia-infected nymphs with positive bloodmeal identification, none fed on deer, indicating that multiple vertebrate species are contributing to sylvatic maintenance of Ehrlichia spp. at these sites. This highlights the difficulty of attempting to reduce the risk of tick-borne disease through host-targeted interventions alone.
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Affiliation(s)
- Jessica R Harmon
- University of Tennessee Institute of Agriculture, Entomology and Plant Pathology Department, United States; University of Tennessee Institute of Agriculture, Center for Wildlife Health, United States.
| | - M Cathy Scott
- University of Tennessee Institute of Agriculture, Center for Wildlife Health, United States
| | - Ellen M Baker
- University of Tennessee Institute of Agriculture, Center for Wildlife Health, United States
| | - Carl J Jones
- University of Tennessee Institute of Agriculture, Entomology and Plant Pathology Department, United States
| | - Graham J Hickling
- University of Tennessee Institute of Agriculture, Center for Wildlife Health, United States
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Lee S, Kakumanu ML, Ponnusamy L, Vaughn M, Funkhouser S, Thornton H, Meshnick SR, Apperson CS. Prevalence of Rickettsiales in ticks removed from the skin of outdoor workers in North Carolina. Parasit Vectors 2014; 7:607. [PMID: 25533148 PMCID: PMC4301950 DOI: 10.1186/s13071-014-0607-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 12/16/2014] [Indexed: 11/29/2022] Open
Abstract
Background Tick-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. Methods Ticks 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. Results The 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. Conclusions We 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 material The online version of this article (doi:10.1186/s13071-014-0607-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sangmi Lee
- Department of Entomology, North Carolina State University, Campus Box 7647, Raleigh, NC, 27695-7647, USA. .,Present address: National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Madhavi L Kakumanu
- Department of Entomology, North Carolina State University, Campus Box 7647, Raleigh, NC, 27695-7647, USA.
| | - Loganathan Ponnusamy
- Department of Entomology, North Carolina State University, Campus Box 7647, Raleigh, NC, 27695-7647, USA.
| | - Meagan Vaughn
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Sheana Funkhouser
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Haley Thornton
- Department of Entomology, North Carolina State University, Campus Box 7647, Raleigh, NC, 27695-7647, USA.
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Charles S Apperson
- Department of Entomology, North Carolina State University, Campus Box 7647, Raleigh, NC, 27695-7647, USA.
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Mays SE, Hendricks BM, Paulsen DJ, Houston AE, Trout Fryxell RT. Prevalence of five tick-borne bacterial genera in adult Ixodes scapularis removed from white-tailed deer in western Tennessee. Parasit Vectors 2014; 7:473. [PMID: 25331818 PMCID: PMC4207311 DOI: 10.1186/s13071-014-0473-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 10/02/2014] [Indexed: 11/10/2022] Open
Abstract
Background In the northeastern and midwestern regions of the United States Ixodes scapularis Say transmits the causal agents of anaplasmosis (Anaplasma phagocytophilum), babesiosis (Babesia microti), and borreliosis (Borrelia burgdorferi and B. miyamotoi). In the southeastern United States, none of those pathogens are considered endemic and two other tick-borne diseases (TBDs) (ehrlicihosis and rickettiosis) are more common. Our objective was to determine baseline presence and absence data for three non-endemic bacterial agents (Anaplasma, Borrelia and Babesia) and two commonly reported bacterial agents (Ehrlichia, and Rickettsia) in southern I. scapularis (n = 47) collected from 15 hunter-harvested white-tailed deer (Odocoileus virginianus) in western Tennessee. Findings Of the 47 ticks, 27 tested PCR positive for non-pathogenic Rickettsia species, two for Ehrlichia ewingii, one for Ehrlichia sp. “Panola Mountain”, and one for Anaplasma phagocytophilum variant 1 strain. None of these ticks were positive for Babesia or Borrelia (including B. burgdorferi). Conclusions Finding human pathogens in host-fed I. scapularis merits additional studies surveying pathogen prevalence in questing ticks. Collection of questing I. scapularis in their peak activity months should be undertaken to determine the overall encounter rates and relative risk of pathogenic Ehrlichia in southern I. scapularis. Ehrlichia sequences were homologous to previous human isolates, but neither Babesia nor B. burgdorferi were identified in these ticks. With the identification of pathogenic bacteria in this relatively small collection of I. scapularis from western Tennessee, the study of the absence of Lyme disease in the south should be refocused to evaluate the role of pathogenic Ehrlichia in southern I. scapularis.
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Affiliation(s)
- Sarah E Mays
- Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Building 2505 E J Chapman Drive, Knoxville, TN, USA.
| | - Brian M Hendricks
- Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Building 2505 E J Chapman Drive, Knoxville, TN, USA.
| | - David J Paulsen
- Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Building 2505 E J Chapman Drive, Knoxville, TN, USA.
| | - Allan E Houston
- Department of Forestry, Fisheries, and Wildlife, University of Tennessee, Tennessee and Ames Plantation, Grand Junction, Knoxville, Tennessee, USA.
| | - Rebecca T Trout Fryxell
- Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Building 2505 E J Chapman Drive, Knoxville, TN, USA.
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Ehrlichia chaffeensis infection in the reservoir host (white-tailed deer) and in an incidental host (dog) is impacted by its prior growth in macrophage and tick cell environments. PLoS One 2014; 9:e109056. [PMID: 25303515 PMCID: PMC4193820 DOI: 10.1371/journal.pone.0109056] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/01/2014] [Indexed: 12/29/2022] Open
Abstract
Ehrlichia chaffeensis, transmitted from Amblyomma americanum ticks, causes human monocytic ehrlichiosis. It also infects white-tailed deer, dogs and several other vertebrates. Deer are its reservoir hosts, while humans and dogs are incidental hosts. E. chaffeensis protein expression is influenced by its growth in macrophages and tick cells. We report here infection progression in deer or dogs infected intravenously with macrophage- or tick cell-grown E. chaffeensis or by tick transmission in deer. Deer and dogs developed mild fever and persistent rickettsemia; the infection was detected more frequently in the blood of infected animals with macrophage inoculum compared to tick cell inoculum or tick transmission. Tick cell inoculum and tick transmission caused a drop in tick infection acquisition rates compared to infection rates in ticks fed on deer receiving macrophage inoculum. Independent of deer or dogs, IgG antibody response was higher in animals receiving macrophage inoculum against macrophage-derived Ehrlichia antigens, while it was significantly lower in the same animals against tick cell-derived Ehrlichia antigens. Deer infected with tick cell inoculum and tick transmission caused a higher antibody response to tick cell cultured bacterial antigens compared to the antibody response for macrophage cultured antigens for the same animals. The data demonstrate that the host cell-specific E. chaffeensis protein expression influences rickettsemia in a host and its acquisition by ticks. The data also reveal that tick cell-derived inoculum is similar to tick transmission with reduced rickettsemia, IgG response and tick acquisition of E. chaffeensis.
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Killmaster LF, Loftis AD, Zemtsova GE, Levin ML. Detection of bacterial agents in Amblyomma americanum (Acari: Ixodidae) from Georgia, USA, and the use of a multiplex assay to differentiate Ehrlichia chaffeensis and Ehrlichia ewingii. JOURNAL OF MEDICAL ENTOMOLOGY 2014; 51:868-872. [PMID: 25118421 PMCID: PMC5659119 DOI: 10.1603/me13225] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Amblyomma americanum, the lone star tick, is the most common and most aggressive human biting tick in the Southeastern United States. It is known to transmit the agents of human ehrlichioses, Ehrlichia chaffeensis and Ehrlichia ewingii. In addition, it carries agents of unspecified pathogenicity to humans, including Rickettsia amblyommii, Borrelia lonestari, and the newly emerging Panola Mountain Ehrlichia (PME). Surveillance of these ticks for recognized or emerging pathogens is necessary for assessing the risk of human infection. From 2005 to 2009, we surveyed A. americanum ticks from four locations in the state of Georgia. Ticks (1,183 adults, 2,954 nymphs, and 99 larval batches) were tested using a multiplex real-time polymerase chain reaction (PCR) assay designed to detect and discriminate DNA from Rickettsia spp., E. chaffeensis, and E. ewingii. This assay was capable of detecting as few as 10 gene copies of the aforementioned agents. Ticks were also tested for PME and B. lonestari by nested PCR. The prevalence of infection ranged from 0 to 2.5% for E. chaffeensis, 0 to 3.9% for E. ewingii, 0 to 2.2% for PME, 17 to 83.1% for R. amblyommii, and 0 to 3.1% for B. lonestari. There were 46 (4.1%) individual adults positive for two agents, and two females that were each positive for three agents. Two larval batches were positive for both B. lonestari and R. amblyommii, indicating the potential for transovarial transmission of both agents from a single female. Although infrequent in occurrence, the dynamics of coinfections in individual ticks should be explored further, given the potential implications for differential diagnosis and severity of human illness.
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Social-ecological factors determine spatial variation in human incidence of tick-borne ehrlichiosis. Epidemiol Infect 2013; 142:1911-24. [DOI: 10.1017/s0950268813002951] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
SUMMARYThe spatial distribution of human cases of tick-borne diseases is probably determined by a combination of biological and socioeconomic factors. A zoonotic tick-borne pathogen, Ehrlichia chaffeensis, is increasing in human incidence in the USA. In this study, the spatial patterns of probable and confirmed E. chaffeensis-associated cases of ehrlichiosis from 2000 to 2011 were investigated at the zip-code level in Missouri. We applied spatial statistics, including global and local regression models, to investigate the biological and socioeconomic factors associated with human incidence. Our analysis confirms that the distribution of ehrlichiosis in Missouri is non-random, with numerous clusters of high incidence. Furthermore, we identified significant, but spatially variable, associations between incidence and both biological and socioeconomic factors, including a positive association with reservoir host density and a negative association with human population density. Improved understanding of local variation in these spatial factors may facilitate targeted interventions by public health authorities.
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Fritzen CM, Huang J, Westby K, Freye JD, Dunlap B, Yabsley MJ, Schardein M, Dunn JR, Jones TF, Moncayo AC. Infection prevalences of common tick-borne pathogens in adult lone star ticks (Amblyomma americanum) and American dog ticks (Dermacentor variabilis) in Kentucky. Am J Trop Med Hyg 2011; 85:718-23. [PMID: 21976578 DOI: 10.4269/ajtmh.2011.10-0583] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Rocky Mountain spotted fever, Lyme disease, and ehrlichiosis are tick-borne diseases that are reported annually in Kentucky. We conducted a survey to describe infection prevalence of tick-borne pathogens in Amblyomma americanum and Dermacentor variabilis ticks collected in Kentucky. During 2007-2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Rickettsia spp., Borrelia spp., and Ehrlichia spp. by using polymerase chain reaction. Forty-one (14.3%) ticks (31 A. americanum and 10 D. variabilis) were polymerase chain reaction-positive for a Rickettsia spp. Fourteen (4.9%) ticks (6 A. americanum and 8 D. variabilis) were positive for E. chaffeensis, and 4 A. americanum (1.4%) were positive for E. ewingii. One (0.4%) A. americanum was positive for Borrelia lonestari. Although Rocky Mountain spotted fever is diagnosed in Kentucky, no R. rickettsii was found in ticks in this study.
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Affiliation(s)
- Charissa M Fritzen
- Tennessee Department of Health, Vector-Borne Diseases Section, Communicable and Environmental Diseases, Nashville, USA.
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Abstract
In the time since canine ehrlichiosis due to Ehrlichia canis was first described in 1935 and first recognized in the United States in 1962, many key advances have been made in our understanding of the diversity of the rickettsial organisms responsible for ehrlichiosis and anaplasmosis in dogs and, occasionally, cats, the vectors capable of transmitting these agents, and the role these organisms play as both important veterinary pathogens and zoonotic disease agents. Despite considerable progress in the field, much remains to be learned regarding mechanisms contributing to pathogenesis, effective treatment modalities, and prevention strategies that best protect pet health. This article highlights current understanding of the transmission, diagnosis, and management of ehrlichiosis and anaplasmosis in dogs and cats.
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Affiliation(s)
- Susan E Little
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078-2007, USA.
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