Tick Studies Virginia
Sent to Epidemiologist Division for answers. (June 14, 2011)
1. Have any strains/species of Rickettsia, aside from R. parkeri and R. rickettsii, been found in ticks in Virginia? Will you please send studies indicating any testing performed on ticks and the findings?
2. Have any strains/species of Bartonella been detected in ticks in Virginia, aside from the B. tamiae-like discovery and B. vinsonii? Will you please send studies indicating any testing performed on ticks and the findings?
3. Have any strains/species of Babesia been detected in ticks in Virginia? Will you please send studies indicating any testing performed on ticks and the findings?
4. Have any strains/species of Ehrlichiosis or Anaplasma been detected in ticks in Virginia, aside from E. Panola Mountain found in white-tail deer (presumed to be transmitted by ticks)? Will you please send studies indicating any testing performed on ticks and the findings?
RESPONSE-
From: David.Gaines@vdh.virginia.gov
Subject: RE: Infections in Virginia ticks
Date: June 14, 2011 4:21:57 PM EDT
Until recently the only testing done on ticks collected in Virginia has been done by the Virginia Department of Health, and the Fairfax County Department of Health for Borrelia burgdorferi. However there are several new groups of people associated with Universities in Virginia that are collecting ticks and testing them for a variety of different pathogens, and the tick surveillance program at the Fairfax County Department of Health began testing ticks for a wide variety of pathogens in 2010.
The groups looking at Rickettsia species include persons in the Old Dominion University (ODU) Department of Biology (Drs. Wayne Hynes and Holly Gaff, who have focused primarily on Rickettsia parkeri but are also testing for other agents) and the group at the Fairfax County Dept. of Health (Dr. Jorge Arias and staff) who have been testing the ticks they collect for a wide variety of pathogens at a laboratory at Johns Hopkins U.
There is also a group headed by Dr. Brinkerhoff at the University of Richmond that is doing tick surveillance for B. burgdorferi and may expand their testing to a wider range of pathogens. Thus far, I do not have collection and testing data from the group at ODU for anything other than R. parkeri (found in 51% of their collected Amblyomma maculatum).
In 2010, the Fairfax County group found Rickettsia amblyommii in 26% of their tested Amblyomma americanum, and in 1 % of their tested A. maculatum. They have also found Rickettsia andeane in 0.6% of their tested A. maculatum, Rickettsia montanensis in 0.97% of their tested Dermacentor variabilis and R. Parkeri in 41% of their A. maculatum and in 0.3% of tested D. variabilis.
I know of no group in Virginia that is testing ticks for Bartonella. In 2009, I submitted about 1,000 Ix. scapularis to a laboratory at the NCSU School of Veterinary Science to be tested for B. burgdorferi . I was told that these ticks would subsequently be tested for infection with Bartonella species as part of their own research program. I am not sure if that Bartonella testing was ever completed and am unaware if they found anything interesting.
The only program that I know of that has tested ticks for Babesia in Virginia is the program run by Melissa Miller at the U.S. Army Public Health Command (North), Fort Mead, MD. I do not know the total number of Ix. scapularis they have tested for Babesia, but I think they have tested a lot of ticks and have only one, or possibly two records of Babesia positive ticka from Virginia. To my knowledge, those samples have not yet been sequenced, so it s not known which Babesia species was found.
In 2006 we tested hundreds of Ix. scapularis for Anaplasma phagocytophilum, and had about a 30% positivity rate in the samples, but as these ticks had been collected off of hunter killed deer, it became evident that the PCR was detecting a non-pathogenic species of Anaplasma carried by deer. The only data I have on Ehrlichiosis and Anaplasmosis comes from the Fairfax County program. In 2010 they detected Ehrlichia chaffeensis in 6% of the A. americanum they tested and Anaplasma phagocytophilum in 0.56% of the Ix. scapularis they tested.
David N. Gaines
State Public Health Entomologist
Virginia Dept. of Health
Division of Environmental Epidemiology
Richmond, VA
804-864-8112 – Office
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Vector Borne Zoonotic Dis. 2014 Apr 18. [Epub ahead of print]
Gaines DN1, Operario DJ, Stroup S, Stromdahl E, Wright C, Gaff H, Broyhill J, Smith J, Norris DE, Henning T, Lucas A,Houpt E.
Abstract
Abstract The population of the lone star tick Amblyomma americanum has expanded in North America over the last several decades. It is known to be an aggressive and nondiscriminatory biter and is by far the most common human-biting tick encountered in Virginia.
Few studies of human pathogen prevalence in ticks have been conducted in our state since the mid-twentieth century. We developed a six-plex real-time PCR assay to detect three Ehrlichia species (E. chaffeensis, E. ewingii, and Panola Mountain Ehrlichia) and three spotted fever group Rickettsiae (SFGR; R. amblyommii, R. parkeri, and R. rickettsii) and used it to test A. americanum from around the state.
Our studies revealed a presence of all three Ehrlichia species (0-24.5%) and a high prevalence (50-80%) of R. amblyommii, a presumptively nonpathogenic SFGR, in all regions surveyed. R. parkeri, previously only detected in Virginia's Amblyomma maculatum ticks, was found in A. americanum in several surveyed areas within two regions having established A. maculatum populations. R. rickettsii was not found in any sample tested. Our study provides the first state-wide screening of A. americanum ticks in recent history and indicates that human exposure to R. amblyommii and to Ehrlichiae may be common.
The high prevalence of R. amblyommii, serological cross-reactivity of all SFGR members, and the apparent rarity of R. rickettsii in human biting ticks across the eastern United States suggest that clinical cases of tick-borne disease, including ehrlichiosis, may be commonly misdiagnosed as Rocky Mountain spotted fever, and that suspicion of other SFGR as well as Ehrlichia should be increased. These data may be of relevance to other regions where A. americanum is prevalent.
PMID: 24746145 [PubMed - as supplied by publisher]
To cite this article:
Natalie A. Cherry, Ricardo G. Maggi, John H. Rossmeisl, Barbara C. Hegarty and Edward B. Breitschwerdt. Vector-Borne and Zoonotic Diseases. -Not available-, ahead of print. doi:10.1089/vbz.2010.0201.
Online Ahead of Print: July 7, 2011
Full Text: • HTML • PDF for printing (206 KB) • PDF w/ links (146.6 KB)
Natalie A. Cherry,1
Ricardo G. Maggi,1
John H. Rossmeisl,2
Barbara C. Hegarty,1 and
Edward B. Breitschwerdt1
1Intracellular Pathogens Research Laboratory and the Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.
2Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia.
Address correspondence to:
Edward B. Breitschwerdt
Intracellular Pathogens Research Laboratory and the Center for Comparative Medicine and Translational Research
College of Veterinary Medicine
North Carolina State University
4700 Hillsborough St.
Raleigh, NC 27606
E-mail: ed_breitschwerdt@ncsu.edu
Abstract
Bartonella species comprise a genus of gram-negative, fastidious, intracellular bacteria that have been implicated in association with an increasing spectrum of disease manifestations in dogs and human patients. In this study, chronic canine and human disease, for which causation was not diagnostically defined, were reported by the breeder of a kennel of Doberman pinschers. In addition to other diagnostic tests, serology, polymerase chain reaction, and enrichment blood culture were used to assess the prevalence of Bartonella sp. infection in the dogs and their owner. From five dogs, Bartonella vinsonii subsp. berkhoffii genotype I, multiple Bartonella henselae strains, and a species most similar to Candidatus B. volans, a rodent-associated Bartonella sp., were amplified and sequenced from biopsy tissues, cerebrospinal fluid, or blood enrichment cultures. The owner was bacteremic with B. vinsonii subsp. berkhoffii genotype I, the same subsp. and genotype detected in one of her dogs. These results further emphasize the ecological complexity of Bartonella sp. transmission in nature.
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Volume 17, Number 5–May 2011
Dispatch
Chelsea L. Wright, Robyn M. Nadolny, Ju Jiang, Allen L. Richards, Daniel E. Sonenshine, Holly D. Gaff, and Wayne L. Hynes Author affiliations: Old Dominion University, Norfolk, Virginia, USA (C.L. Wright, R. Nadolny, D.E. Sonenshine, H.D. Gaff, W.L. Hynes); and Naval Medical Research Center, Silver Spring, Maryland, USA (J. Jiang, A.L. Richards)
Abstract
We report evidence that Amblyomma maculatum tick populations are well established in southeastern Virginia. We found that 43.1% of the adult Gulf Coast ticks collected in the summer of 2010 carried Rickettsia parkeri, suggesting that persons living in or visiting southeastern Virginia are at risk for infection with this pathogen.
Rickettsia parkeri is an obligate intracellular bacterium belonging to the spotted fever group of rickettsiae; this organism has recently been found to be pathogenic to humans (1). Infection with R. parkeri can be considered an emerging infectious disease, referred to as R. parkeri rickettsiosis, American Boutonneuse fever, and Tidewater spotted fever. Two confirmed cases of R. parkeri infections, including the index case in 2002, occurred in southeastern Virginia (1–3). Since then, 20 R. parkeri infections have been reported, mainly from the southern United States (2). In the United States, Amblyomma maculatum (familyIxodidae) ticks, commonly referred to as Gulf Coast ticks, are the only known natural vector of R. parkeri. A. maculatum ticks have been reported from 12 states: Alabama, Arkansas, Florida, Georgia, Kansas, Kentucky, Mississippi, Oklahoma, South Carolina, Tennessee, Texas (1,4,5), and Virginia (6). Sonenshine et al. reported finding individual A. maculatumticks in Virginia in 1965 but concluded that populations had not become established (7).
We found large numbers of adult and some nymph A. maculatum ticks in Virginia. This population and the different life stages of the ticks indicate that they are now established in the state. Testing by real-time PCR and sequencing indicated that a high percentage of the ticks contained R. parkeri DNA.
From May through September 2010, adult questing A. maculatum ticks were collected on flags at 3 locations in southeastern Virginia. Collection sites were selected to produce results that could be compared with those of previous surveys and to provide a comprehensive survey of southeastern Virginia (8). The first study site is 50 km inland and borders the Great Dismal Swamp in Chesapeake, Virginia. The second site, Back Bay National Wildlife Refuge, is <1 km from the Atlantic Ocean in Virginia Beach. The third site, in Portsmouth, borders the Elizabeth River.
The ticks were identified morphologically, and identity was confirmed as needed by molecular methods. DNA was extracted by using the DNeasy Blood and Tissue Kit (QIAGEN, Valencia, CA, USA) according to the manufacturer's protocol and stored at –20°C until processing.
DNA samples were tested for R. parkeri DNA by real-time PCR with a MiniOpticon Real-Time PCR System (Bio-Rad, Hercules, CA, USA). Testing for R. parkeri DNA was by amplification and detection of a fragment of the ompB gene by using Rpa129F and Rpa224R primers and Rpa188 as the probe (Table 1). Samples negative for R. parkeri DNA were tested for Rickettsia spp. by amplifying a 111-bp fragment of the 17-kDa antigen gene (Table 1).
Three representative A. maculatum samples positive for R. parkeri by real-time PCR were confirmed by sequencing of a 540-bp fragment of the ompA gene. The fragments were amplified on an iCycler (Bio-Rad) by using primers 190-FN1 and 190-RN1 (Table 1). Samples positive for Rickettsia spp. but negative for R. parkeri had their ompB gene amplified and sequenced by using primers RompB11F and RompB1902R (Table 1). All PCR products for sequencing were purified by using Wizard PCR Preps DNA Purification System (Promega, Madison, WI, USA), and sequencing reactions were performed by using the BigDye Terminator v.3.1 Cycle Sequencing Kit (Applied Biosystems, Foster City, CA, USA) as described by the manufacturer and using appropriate primers (Table 1). Sequence similarities were identified by a BLAST search (http://blast.ncbi.nlm.nih.gov).
A total of 65 adult and 6 nymph A. maculatum ticks were collected (adults in May–September, nymphs in April). A total of 54 adults were collected from the Chesapeake site, 8 from the Virginia Beach site, and 3 from the Portsmouth site. Of the 6 nymphs collected, 5 were found feeding on a cotton rat at the Chesapeake site in April, and 1 was collected on a flag at the Virginia Beach site in September. Of the 65 total adult ticks tested, 29 (44.6%) were found by real-time PCR to contain Rickettsia spp. DNA, and 28 (43.1%) of the total adults collected contained R. parkeri DNA. Of the 6 nymphs collected, 4 were infected withR. parkeri; all were from the rat at the Chesapeake site. Of the R. parkeri–positive samples sequenced, maximum identity was seen with R. parkeri sequences (GenBank accession no. FJ986616.1). The rate of R. parkeri–infected ticks started out high in May (83% infected) and then decreased to no infected ticks in August (Table 2).
Of the 3 A. maculatum ticks collected from the Portsmouth site, 1 was found by real-time PCR to be positive for Rickettsia spp. but negative for R. parkeri. Sequencing of a fragment of the ompB gene revealed this isolate to contain DNA with a 100% match to CandidatusRickettsia andeanae isolate T163 (GenBank accession no. GU395297.1), a rickettsiae initially found in Peru (9).
The discovery of such numbers and life stages of A. maculatum ticks in widely dispersed locations indicates that they are now established in southeastern Virginia. Finding adult A. maculatum ticks at the Portsmouth site was unexpected because this is the northernmost site at which we found these ticks and is a peninsula devoid of white-tailed deer, a major host for adult ticks (10,11).
That 43.1% of adult A. maculatum ticks collected from southeastern Virginia contained R. parkeri differs from reported rates of R. parkeri in A. maculatum ticks elsewhere in the United States. For A. maculatum ticks from Florida and Mississippi, R. parkeri infectivity rate is 28% (2); for ticks from Florida, Kentucky, Mississippi, and South Carolina, the average rate is 11.5% (12). For A. maculatum ticks collected from Georgia, an infectivity rate of 5%–11.5% has been reported (13). In Arkansas, only 3 of 207 A. maculatum ticks contained R. parkeri (14). Despite the high percentage of R. parkeri in the southeastern Virginia ticks, 27 of 28 positive samples came from 1 collection site. One explanation could be that R. parkeriis transovarially transmitted. Currently, there is no evidence that R. parkeri is transmitted transovarially by A. maculatum ticks, although transovarial transmission of R. parkeri has been shown in A. americanum ticks in the laboratory (15).
We also found an A. maculatum tick infected with Candidatus Rickettsia andeanae, which has rarely been reported in the United States (2). Whether Candidatus Rickettisa andeanae is pathogenic to humans is unknown, although it has been suspected to cause infections in persons in Peru (9).
Further research is needed to identify the vertebrate host(s) of R. parkeri. This information could be useful for controlling the transmission of R. parkeri to and from the vector, as well as predicting where R. parkeri may be present. Studies relating to transovarial transmission of R. parkeri in A. maculatum ticks would also be useful for predicting the spread of infections. Because R. parkeri is known to cause infection in humans, the presence of this pathogen in southeastern Virginia should be a health concern to persons in this region.
Acknowledgments
We thank Brandon Rowan and Ryan Wright for their help with collecting ticks. We also acknowledge the Nature Conservancy, the Back Bay Wildlife Refuge, and Elizabeth River Project for permission to use their land.
The project described was supported by grant no. K25AI067791 (to H.D.G.) from the National Institute of Allergy and Infectious Diseases. This work was supported by the US Department of Defense Global Emerging Infections Surveillance and Response System program (work unit no. 0000188M.0931.001.A0074).
Ms Wright is a PhD student in the Biological Sciences Department at Old Dominion University. Her research interests lie in microbiology, tick-borne pathogens, and infectious diseases.
References
Wright CL, Nadolny RM, Jiang J, Richards AL, Sonenshine DE, Gaff HD, et al. Rickettsia parkeri in Gulf Coast ticks, southeastern Virginia, USA. Emerg Infect Dis [serial on the Internet]. 2011 May [date cited]. http://www.cdc.gov/EID/content/17/5/896.htm
DOI: 10.3201/eid1705.101836
Comments to the Authors
Please use the form below to submit correspondence to the authors or contact them at the following address:
Wayne L. Hynes, Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529, USA; email: whynes@odu.edu
Full article
http://www.cdc.gov/EID/content/17/5/896.htm
***
Vector Borne Zoonotic Dis. 2005 Winter;5(4):383-9.
Taft SC, Miller MK, Wright SM.
Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio, USA.
Lyme disease is the most commonly reported vector-borne disease in the United States and is transmitted by Borrelia burgdorferi-infected Ixodes species. The disease is typically characterized by an erythema migrans (EM) rash at the site of tick feeding. EM rashes have also been associated with feeding by Amblyomma americanum ticks despite evidence suggesting that they are incompetent vectors for Lyme disease. In 1996, a Borrelia organism only recently cultivated in the laboratory was described in A. americanum ticks and designated B. lonestari. This Borrelia is believed to be the etiologic agent of a novel Lyme-like disease, southern tick associated rash illness (STARI). This study examined ticks collected from eight eastern states to evaluate the epidemiology of B. lonestari, B. burgdorferi, and their tick hosts. Three hundred individual or small pool samples were evaluated from tick genera that included Amblyomma, Ixodes, and Dermacentor. DNA was extracted following tick homogenization and the polymerase chain reaction (PCR) was performed using primers derived from the flagellin gene that amplify sequences from both B. burgdorferi and B. lonestari. Species specific digoxigenin labeled probes were designed and used to differentiate between B. burgdorferi and B. lonestari. Borrelia DNA was detected in approximately 10% of the A. americanum and I. scapularis tick samples, but none was present in any of the Dermacentor samples tested. Positive samples were detected in ticks collected from Kentucky, Maryland, Massachusetts, New Jersey, New York, and Virginia. This is the first known report of B. lonestari from Massachusetts and New York and the first detection in I. scapularis. This suggests that B. lonestari and its putative association with STARI may be more widespread than previously thought.
PMID: 16417434 [PubMed - indexed for MEDLINE]
The effects of vegetation density and habitat disturbance on the spatial distribution of ixodid ticks (Acari: Ixodidae)
Kenneth J. Stein1, Megan Waterman2, Jefferson L. Waldon1 1 Conservation Management Institute, College of Natural Resources and 2Department of Statistics, College of Science, Virginia Polytechnic Institute and State University, Blacksburg,VA 24061, USA
Abstract.Larval, nymphal, and adult Amblyomma americanum(L.), and adult Dermacentor variabilis(Say) ticks were collected using timed dragging techniques, in an attempt to examine how different habitat variables affect models that describe the distribution of ticks in Virginia, USA. Tick count data were modeled using two approaches: (i) habitat and edge, and (ii) habitat, edge, vegetation density and levels of disturbance. Nymphs and adults tended to follow a forest edge distribution when analysed by habitat and edge. Using all variables, we detected a positive relationship with forest edges and negative associations with high-density vegetation. When larvae were modeled by habitat and edge, we failed to detect associations with the edges of habitats. When all variables were included in the larval analysis, disturbed meadow edges emerged as important in the first year, and the categories of disturbed and maturing habitat in the second year. Vegetation density and levels of disturbance were marginally important towards explaining the distribution of nymphs and adults; however, levels of disturbance were potentially more important to the distribution of larvae, than habitat types. Using the habitat and edge variables, and predicted mean encounter rates for all stages of A. americanum and adult D. variabilis, we successfully cross-validated our predictions of high, moderate and low tick densities in both years. The results for nymphs and adults were combined to develop a colour-coded threat assessment map. We estimated that the majority of ticks were located on ~ 20% of the landscape. The potential uses of geographical informa-
tion system-based threat maps are discussed.
Keywords: ixodid ticks, geographical information system, habitat characterization, spatial distribution, predictive
Geospatial Health 2(2), 2008, pp. 241-252
Full article
PARASITES, DISEASES, AND HEALTH STATUS OF SYMPATRIC
POPULATIONS OF SIKA DEER AND WHITE-TAILED DEER
IN MARYLAND AND VIRGINIA
William R. Davidson and Church B. Crow
Southeastern Cooperative Wildlife Disease Study, Department of Parasitology,
College of Veterinary Medicine, The University of Georgia,
Athens, Georgia 30602, USA
ABSTRACT: In July 1981, investigations on parasites, diseases, and herd health status were conducted on
sympatnic populations of sika deer (Cervus nippon) and white-tailed deer (Odocoileus virginianus) from
B!ackwater National Wildlife Refuge (Maryland) and Chincoteague National Wildlife Refuge (Virginia) on
the Delmarva Peninsula. Five adult deer of each species were collected from each location and subjected to
thorough necropsy examinations and laboratory tests. White-tailed deer at both locations harbored protozoan,
helminth, and arthropod parasites typically associated with this species throughout the southeastern United
States. In contrast, sika deer at both locations harbored only light burdens of ticks, chiggers, and sarcocysts.
Serologic tests for antibodies to seven infectious disease agents revealed evidence of exposure to bovine virus
diarrhea (BVD) virus, infectious bovine rhinotracheitis virus, and parainfluenza3 virus in white-tailed deer,
but only BVD virus in sika deer. At both locations the general health status of sika deer was superior to that
of white-tailed deer.
Full article:
http://www.jwildlifedis.org/cgi/reprint/19/4/345
Journal of Wildlife Diseases, 44(2), 2008, pp. 381-387
© Wildlife Disease Association 2008
Michael J. Yabsley1,2,5, Amanda D. Loftis3 and Susan E. Little4
1 Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia 30602, USA
2 Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, USA
3 Viral and Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
4 Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, Oklahoma 74078, USA
5 Corresponding author (email: myabsley@uga.edu)
ABSTRACT: An Ehrlichia sp. (Panola Mountain [PM] Ehrlichia sp.) closely related to Ehrlichia ruminantium was recently detected in a domestic goat experimentally infested with lone star ticks (LSTs, Amblyomma americanum) collected from Georgia, USA. The infected goat exhibited pyrexia and mild clinical pathologic abnormalitiesconsistent with ehrlichiosis. At least two other Ehrlichia species (Ehrlichia chaffeensis and Ehrlichia ewingii) are maintained in nature by a cycle involving LSTs as the primary vector and white-tailed deer (Odocoileus virginanus) as a known or suspected reservoir. To investigate the possibility that white-tailed deer are potential hosts of the PM Ehrlichia sp., whole bloodsamples collected from 87 wild deer from 2000 to 2002 were screened with a species-specific nested PCR assay targeting the citrate synthase gene. In addition, two laboratory-raised white-tailed deer fawns were each infested with 120 wild-caught LST adults from Missouri, USA, and blood samples were periodically collected and tested for the PM Ehrlichia sp. Of 87 deer tested from 20 locations in the southeastern United States, three (3%) deer from Arkansas, North Carolina, and Virginia were positive for the PM Ehrlichia sp. Wild-caught ticks transmitted the PM Ehrlichia sp. to one of two deer fawns, and colony-reared nymphal LSTs acquired the organism from the deer, maintained it transstadially as they molted to adults, and transmitted the PM Ehrlichia sp. to two naïve fawns. These findings indicate that white-tailed deer are naturally and experimentally susceptible to infection with an Ehrlichia sp. closely related to E. ruminantium and are able to serve as a source of infection to LSTs.
Key words: Amblyomma, cervid, Cowdria, Ehrlichia chaffeensis, Ehrlichia ruminantium, heartwater, lone star tick.
Full article