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Foley N, O’Connor C, Falco RC, Vinci V, Oliver J, Haight J, Sporn LA, Harrington L, Mader E, Wroblewski D, Backenson PB, Prusinski MA. Spatiotemporal distribution of Borrelia miyamotoi (Spirochaetales: Spirochaetaceae) and coinfection with other tick-borne pathogens in host-seeking Ixodes scapularis (Acari: Ixodidae) from New York State, USA. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:808-821. [PMID: 37156099 PMCID: PMC10653143 DOI: 10.1093/jme/tjad054] [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: 09/22/2022] [Revised: 04/06/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023]
Abstract
Blacklegged ticks (Ixodes scapularis Say, Acari: Ixodidae) were collected from 432 locations across New York State (NYS) during the summer and autumn of 2015-2020 to determine the prevalence and geographic distribution of Borrelia miyamotoi (Spirochaetales: Spirochaetaceae) and coinfections with other tick-borne pathogens. A total of 48,386 I. scapularis were individually analyzed using a multiplex real-time polymerase chain reaction assay to simultaneously detect the presence of Bo. miyamotoi, Borrelia burgdorferi (Spirochaetales: Spirochaetaceae), Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae), and Babesia microti (Piroplasmida: Babesiidae). Overall prevalence of Bo. miyamotoi in host-seeking nymphs and adults varied geographically and temporally at the regional level. The rate of polymicrobial infection in Bo. miyamotoi-infected ticks varied by developmental stage, with certain co-infections occurring more frequently than expected by chance. Entomological risk of exposure to Bo. miyamotoi-infected nymphal and adult ticks (entomological risk index [ERI]) across NYS regions in relation to human cases of Bo. miyamotoi disease identified during the study period demonstrated spatial and temporal variation. The relationship between select environmental factors and Bo. miyamotoi ERI was explored using generalized linear mixed effects models, resulting in different factors significantly impacting ERI for nymphs and adult ticks. These results can inform estimates of Bo. miyamotoi disease risk and further our understanding of Bo. miyamotoi ecological dynamics in regions where this pathogen is known to occur.
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Affiliation(s)
- Nicole Foley
- Department of Entomology, Cornell University, 3138/2130 Comstock Hall, Ithaca, NY 14853, USA
| | - Collin O’Connor
- New York State Department of Health, Bureau of Communicable Disease Control, Western New York Regional Office, 584 Delaware Avenue, Buffalo, NY 14202, USA
- Department of Geography, University at Buffalo, Suite 105, Buffalo, NY, 14261, USA
| | - Richard C Falco
- New York State Department of Health, Fordham University, Vector Ecology Laboratory, Louis Calder Center, 53 Whippoorwill Road, Armonk, NY 10504, USA
| | - Vanessa Vinci
- New York State Department of Health, Fordham University, Vector Ecology Laboratory, Louis Calder Center, 53 Whippoorwill Road, Armonk, NY 10504, USA
| | - JoAnne Oliver
- New York State Department of Health, Bureau of Communicable Disease Control, Central New York Regional Office, 217 South Salina Street, 3rd Floor, Syracuse, NY 13202, USA
| | - Jamie Haight
- New York State Department of Health, Bureau of Communicable Disease Control, Chautauqua County DPF Offices, 454 North Work Street, Room B-05, Falconer, NY 14733, USA
| | - Lee Ann Sporn
- Paul Smith’s College, State Routes 30 and 86, Paul Smiths, NY 12970, USA
| | - Laura Harrington
- Department of Entomology, Cornell University, 3138/2130 Comstock Hall, Ithaca, NY 14853, USA
| | - Emily Mader
- Department of Entomology, Cornell University, 3138/2130 Comstock Hall, Ithaca, NY 14853, USA
| | - Danielle Wroblewski
- Wadsworth Center, New York State Department of Health, Bacteriology Laboratory, David Axelrod Institute, 120 New Scotland Avenue, Albany, NY 12208, USA
| | - P Bryon Backenson
- New York State Department of Health, Bureau of Communicable Disease Control, Communicable Disease Investigations and Vector Surveillance Unit, Empire State Plaza, Albany, NY 12237, USA
| | - Melissa A Prusinski
- New York State Department of Health, Bureau of Communicable Disease Control, Vector Ecology Laboratory, Wadsworth Center Biggs Laboratory C-456, Empire State Plaza, Albany, NY 12237, USA
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Burde J, Bloch EM, Kelly JR, Krause PJ. Human Borrelia miyamotoi Infection in North America. Pathogens 2023; 12:553. [PMID: 37111439 PMCID: PMC10145171 DOI: 10.3390/pathogens12040553] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 04/05/2023] Open
Abstract
Borrelia miyamotoi is an emerging pathogen that causes a febrile illness and is transmitted by the same hard-bodied (ixodid) ticks that transmit several other pathogens, including Borrelia species that cause Lyme disease. B. miyamotoi was discovered in 1994 in Ixodes persulcatus ticks in Japan. It was first reported in humans in 2011 in Russia. It has subsequently been reported in North America, Europe, and Asia. B. miyamotoi infection is widespread in Ixodes ticks in the northeastern, northern Midwestern, and far western United States and in Canada. In endemic areas, human B. miyamotoi seroprevalence averages from 1 to 3% of the population, compared with 15 to 20% for B. burgdorferi. The most common clinical manifestations of B. miyamotoi infection are fever, fatigue, headache, chills, myalgia, arthralgia, and nausea. Complications include relapsing fever and rarely, meningoencephalitis. Because clinical manifestations are nonspecific, diagnosis requires laboratory confirmation by PCR or blood smear examination. Antibiotics are effective in clearing infection and are the same as those used for Lyme disease, including doxycycline, tetracycline, erythromycin, penicillin, and ceftriaxone. Preventive measures include avoiding areas where B. miyamotoi-infected ticks are found, landscape management, and personal protective strategies such as protective clothing, use of acaricides, and tick checks with rapid removal of embedded ticks.
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Affiliation(s)
- Jed Burde
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520, USA
| | - Evan M. Bloch
- Division of Transfusion Medicine, Department of Pathology, Johns Hopkins University, Baltimore, MD 21217, USA
| | - Jill R. Kelly
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT 06520, USA
| | - Peter J. Krause
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520, USA
- Department of Medicine, Yale School of Medicine, New Haven, CT 06510, USA
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Hoornstra D, Azagi T, van Eck JA, Wagemakers A, Koetsveld J, Spijker R, Platonov AE, Sprong H, Hovius JW. Prevalence and clinical manifestation of Borrelia miyamotoi in Ixodes ticks and humans in the northern hemisphere: a systematic review and meta-analysis. THE LANCET. MICROBE 2022; 3:e772-e786. [PMID: 36113496 DOI: 10.1016/s2666-5247(22)00157-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/30/2022] [Accepted: 05/31/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND Various studies have evaluated the infection of Ixodes ticks and humans with the relapsing fever spirochaete Borrelia miyamotoi. However, to our knowledge, the prevalence of infection and disease has not been assessed systematically. We aimed to examine the prevalence of B miyamotoi in Ixodes ticks and humans, and the disease it can cause, in the northern hemisphere. METHODS For this systematic review and meta-analysis, we searched PubMed and Web of Science up to March 1, 2021. Studies assessing Ixodes tick infection published since Jan 1, 2011 were eligible, whereas no time limitation was placed on reports of human infection and disease. We extracted B miyamotoi test positivity ratios and used a random-effects model to calculate estimated proportions of infected ticks, infected humans, and human disease with 95% CI. This study was registered with PROSPERO, CRD42021268996. FINDINGS We identified 730 studies through database searches and 316 additional studies that referenced two seminal articles on B miyamotoi. Of these 1046 studies, 157 were included in the review, reporting on 165 637 questing ticks, 45 608 unique individuals, and 504 well described cases of B miyamotoi disease in humans. In ticks, the highest prevalence of B miyamotoi was observed in Ixodes persulcatus (2·8%, 95% CI 2·4-3·1) and the lowest in Ixodes pacificus (0·7%, 0·6-0·8). The overall seroprevalence in humans was 4·4% (2·8-6·3), with significantly (p<0·0001) higher seroprevalences in the high-risk group (4·6%, 2·6-7·1), participants with confirmed or suspected Lyme borreliosis (4·8%, 1·8-8·8), and individuals suspected of having a different tick-borne disease (11·9%, 5·6-19·9) than in healthy controls (1·3%, 0·4-2·8). Participants suspected of having a different tick-borne disease tested positive for B miyamotoi by PCR significantly more often than did the high-risk group (p=0·025), with individuals in Asia more likely to test positive than those in the USA (odds ratio 14·63 [95% CI 2·80-76·41]). INTERPRETATION B miyamotoi disease should be considered an emerging infectious disease, especially in North America and Asia. Prospective studies and increased awareness are required to obtain further insights into the burden of disease. FUNDING ZonMW and the European Regional Development Fund (Interreg).
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Affiliation(s)
- Dieuwertje Hoornstra
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Tal Azagi
- Centre for Infectious Diseases Control, National Institute for Public Health and the Environment, Bilthoven, Netherlands
| | - Jacqueline A van Eck
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Alex Wagemakers
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Joris Koetsveld
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - René Spijker
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | | | - Hein Sprong
- Centre for Infectious Diseases Control, National Institute for Public Health and the Environment, Bilthoven, Netherlands
| | - Joppe W Hovius
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam University Medical Centers, Amsterdam, Netherlands; Amsterdam Institute for Infection and Immunity, Academic Medical Center, Amsterdam University Medical Centers, Amsterdam, Netherlands.
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Jakab Á, Kahlig P, Kuenzli E, Neumayr A. Tick borne relapsing fever - a systematic review and analysis of the literature. PLoS Negl Trop Dis 2022; 16:e0010212. [PMID: 35171908 PMCID: PMC8887751 DOI: 10.1371/journal.pntd.0010212] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/01/2022] [Accepted: 01/27/2022] [Indexed: 02/07/2023] Open
Abstract
Tick borne relapsing fever (TBRF) is a zoonosis caused by various Borrelia species transmitted to humans by both soft-bodied and (more recently recognized) hard-bodied ticks. In recent years, molecular diagnostic techniques have allowed to extend our knowledge on the global epidemiological picture of this neglected disease. Nevertheless, due to the patchy occurrence of the disease and the lack of large clinical studies, the knowledge on several clinical aspects of the disease remains limited. In order to shed light on some of these aspects, we have systematically reviewed the literature on TBRF and summarized the existing data on epidemiology and clinical aspects of the disease. Publications were identified by using a predefined search strategy on electronic databases and a subsequent review of the reference lists of the obtained publications. All publications reporting patients with a confirmed diagnosis of TBRF published in English, French, Italian, German, and Hungarian were included. Maps showing the epidemiogeographic mosaic of the different TBRF Borrelia species were compiled and data on clinical aspects of TBRF were analysed. The epidemiogeographic mosaic of TBRF is complex and still continues to evolve. Ticks harbouring TBRF Borrelia have been reported worldwide, with the exception of Antarctica and Australia. Although only molecular diagnostic methods allow for species identification, microscopy remains the diagnostic gold standard in most clinical settings. The most suggestive symptom in TBRF is the eponymous relapsing fever (present in 100% of the cases). Thrombocytopenia is the most suggestive laboratory finding in TBRF. Neurological complications are frequent in TBRF. Treatment is with beta-lactams, tetracyclines or macrolids. The risk of Jarisch-Herxheimer reaction (JHR) appears to be lower in TBRF (19.3%) compared to louse-borne relapsing fever (LBRF) (55.8%). The overall case fatality rate of TBRF (6.5%) and LBRF (4-10.2%) appears to not differ. Unlike LBRF, where perinatal fatalities are primarily attributable to abortion, TBRF-related perinatal fatalities appear to primarily affect newborns.
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Affiliation(s)
- Ákos Jakab
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Pascal Kahlig
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Esther Kuenzli
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Andreas Neumayr
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Department of Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Queensland, Australia
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5
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Delaney SL, Murray LA, Aasen CE, Bennett CE, Brown E, Fallon BA. Borrelia miyamotoi Serology in a Clinical Population With Persistent Symptoms and Suspected Tick-Borne Illness. Front Med (Lausanne) 2020; 7:567350. [PMID: 33195313 PMCID: PMC7652925 DOI: 10.3389/fmed.2020.567350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/24/2020] [Indexed: 11/13/2022] Open
Abstract
Eighty-two patients seeking consultation for long-term sequalae after suspected tick-borne illness were consecutively tested for Borrelia miyamotoi antibodies using a recombinant glycerophosphodiester phosphodiesterase (GlpQ) enzyme immunoassay. Twenty-one of the 82 patients (26%) tested positive on the GlpQ IgG ELISA. Nearly all of the patients (98%) had no prior B. miyamotoi testing, indicating that clinicians rarely test for this emerging tick-borne pathogen. Compared to patients who solely tested positive for Lyme disease antibodies, patients with B. miyamotoi antibodies presented with significantly more sleepiness and pain. A prospective study is needed to ascertain the relationship between the presence of B. miyamotoi antibodies and persistent symptoms.
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Affiliation(s)
- Shannon L Delaney
- Lyme & Tick-Borne Diseases Research Center, Columbia University Irving Medical Center, New York, NY, United States.,New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, United States
| | - Lilly A Murray
- Lyme & Tick-Borne Diseases Research Center, Columbia University Irving Medical Center, New York, NY, United States.,New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, United States
| | - Claire E Aasen
- Lyme & Tick-Borne Diseases Research Center, Columbia University Irving Medical Center, New York, NY, United States
| | - Clair E Bennett
- Lyme & Tick-Borne Diseases Research Center, Columbia University Irving Medical Center, New York, NY, United States.,New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, United States
| | - Ellen Brown
- Lyme & Tick-Borne Diseases Research Center, Columbia University Irving Medical Center, New York, NY, United States.,New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, United States
| | - Brian A Fallon
- Lyme & Tick-Borne Diseases Research Center, Columbia University Irving Medical Center, New York, NY, United States.,New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, United States
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Han S, Hickling GJ, Ogden NH, Ginsberg HS, Kobbekaduwa V, Rulison EL, Beati L, Tsao JI. Seasonality of acarological risk of exposure to Borrelia miyamotoi from questing life stages of Ixodes scapularis collected from Wisconsin and Massachusetts, USA. Ticks Tick Borne Dis 2020; 12:101556. [PMID: 33035757 DOI: 10.1016/j.ttbdis.2020.101556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 11/28/2022]
Abstract
Measures of acarological risk of exposure to Ixodes scapularis-borne disease agents typically focus on nymphs; however, the relapsing fever group spirochete Borrelia miyamotoi can be passed transovarially, and I. scapularis larvae are capable of transmitting B. miyamotoi to their hosts. To quantify the larval contribution to acarological risk, relative to nymphs and adults, we collected questing I. scapularis for 3 yr at Fort McCoy, Wisconsin (WI, n = 23,367 ticks), and Cape Cod, Massachusetts (MA, n = 4190) in the United States. Borrelia miyamotoi infection prevalence was estimated for I. scapularis larvae, nymphs, females, and males, respectively, as 0.88, 2.05, 0.63, and 1.22 % from the WI site and 0.33, 2.32, 2.83, and 2.11 % from the MA site. Densities of B. miyamotoi-infected ticks (DIT, per 1000 m2) were estimated for larvae, nymphs, females, and males, respectively, as 0.36, 0.14, 0.01, and 0.03 from the WI site and 0.05, 0.06, 0.03, and 0.02 from the MA site. Thus, although larval infection prevalence with B. miyamotoi was significantly lower than that of nymphs and similar to that of adults, because of their higher abundance, the larval contribution to the overall DIT was similar to that of nymphs and trended towards a greater contribution than adults. Assuming homogenous contact rates with humans, these results suggest that eco-epidemiological investigations of B. miyamotoi disease in North America should include larvae. A fuller appreciation of the epidemiological implications of these results, therefore, requires an examination of the heterogeneity in contact rates with humans among life stages.
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Affiliation(s)
- Seungeun Han
- Comparative Medicine and Integrative Biology program, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, United States.
| | - Graham J Hickling
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN 37996, United States.
| | - Nicholas H Ogden
- Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, St-Hyacinthe, QC J2S 2M2, Canada.
| | - Howard S Ginsberg
- U.S. Geological Survey, Patuxent Wildlife Research Center, Kingston, RI 02881, United States.
| | - Vishvapali Kobbekaduwa
- Comparative Medicine and Integrative Biology program, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, United States.
| | - Eric L Rulison
- California Department of Transportation, Redding, CA 96001, United States.
| | - Lorenza Beati
- Department of Biology, Georgia Southern University, Statesboro, GA 30460, United States.
| | - Jean I Tsao
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, 48824, United States; Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI, 48824, United States.
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Vertical transmission rates of Borrelia miyamotoi in Ixodes scapularis collected from white-tailed deer. Ticks Tick Borne Dis 2019; 10:682-689. [PMID: 30846418 DOI: 10.1016/j.ttbdis.2019.02.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 02/16/2019] [Accepted: 02/25/2019] [Indexed: 01/17/2023]
Abstract
Borrelia miyamotoi is a relapsing fever spirochete transmitted by ticks in the Ixodes ricinus complex. In the eastern United States, B. miyamotoi is transmitted by I. scapularis, which also vectors several other pathogens including B. burgdorferi sensu stricto. In contrast to Lyme borreliae, B. miyamotoi can be transmitted vertically from infected female ticks to their progeny. Therefore, in addition to nymphs and adults, larvae can vector B. miyamotoi to wildlife and human hosts. Two widely varying filial infection prevalence (FIP) estimates - 6% and 73% - have been reported previously from two vertically infected larval clutches; to our knowledge, no other estimates of FIP or transovarial transmission (TOT) rates for B. miyamotoi have been described in the literature. Thus, we investigated TOT and FIP of larval clutches derived from engorged females collected from hunter-harvested white-tailed deer in 2015 (n = 664) and 2016 (n = 599) from Maine, New Hampshire, Tennessee, and Wisconsin. After engorged females oviposited in the lab, they (n = 492) were tested for B. miyamotoi infection by PCR. Subsequently, from each clutch produced by an infected female, larval pools, as well as 100 individual eggs or larvae, were tested. The TOT rate of the 11 infected females was 90.9% (95% CI; 57.1-99.5%) and the mean FIP of the resulting larval clutches was 84.4% (95% CI; 68.1-100%). Even though the overall observed vertical transmission rate (the product of TOT and FIP; 76.7%, 95% CI; 44.6-93.3%) was high, additional horizontal transmission may be required for enzootic maintenance of B. miyamotoi based on the results of a previously published deterministic model. Further investigation of TOT and FIP variability and the underlying mechanisms, both in nature and the laboratory, will be needed to resolve this question. Meanwhile, studies quantifying the acarological risk of Borrelia miyamotoi disease need to consider not only nymphs and adults, but larval I. scapularis as well.
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Lynn GE, Breuner NE, Eisen L, Hojgaard A, Replogle AJ, Eisen RJ. An immunocompromised mouse model to infect Ixodes scapularis ticks with the relapsing fever spirochete, Borrelia miyamotoi. Ticks Tick Borne Dis 2019; 10:352-359. [DOI: 10.1016/j.ttbdis.2018.11.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 11/17/2018] [Accepted: 11/26/2018] [Indexed: 11/28/2022]
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9
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Transmission of the relapsing fever spirochete, Borrelia miyamotoi, by single transovarially-infected larval Ixodes scapularis ticks. Ticks Tick Borne Dis 2018; 9:1464-1467. [PMID: 30007502 PMCID: PMC6135663 DOI: 10.1016/j.ttbdis.2018.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/03/2018] [Accepted: 07/09/2018] [Indexed: 12/04/2022]
Abstract
The relapsing fever spirochete, Borrelia miyamotoi, is increasingly recognized as a cause of human illness (hard tick-borne relapsing fever) in the United States. We previously demonstrated that single nymphs of the blacklegged tick, Ixodes scapularis, can transmit B. miyamotoi to experimental hosts. However, two recent epidemiological studies from the Northeastern United States indicate that human cases of hard tick-borne relapsing fever peak during late summer, after the spring peak for nymphal tick activity but coincident with the peak seasonal activity period of larval ticks in the Northeast. These epidemiological findings, together with evidence that B. miyamotoi can be passed from infected I. scapularis females to their offspring, suggest that bites by transovarially-infected larval ticks can be an important source of human infection. To demonstrate experimentally that transovarially-infected larval I. scapularis ticks can transmit B. miyamotoi, outbred Mus musculus CD1 mice were exposed to 1 or 2 potentially infected larvae. Individual fed larvae and mouse blood taken 10 d after larvae attached were tested for presence of B. miyamotoi DNA, and mice also were examined for seroreactivity to B. miyamotoi 8 wk after tick feeding. We documented B. miyamotoi DNA in blood from 13 (57%) of 23 mice exposed to a single transovarially-infected larva and in 5 (83%) of 6 mice exposed to two infected larvae feeding simultaneously. All 18 positive mice also demonstrated seroreactivity to B. miyamotoi. Of the 11 remaining mice without detectable B. miyamotoi DNA in their blood 10 d after infected larvae attached, 7 (64%) had evidence of spirochete exposure by serology 8 wk later. Because public health messaging for risk of exposure to Lyme disease spirochetes focuses on nymphal and female I. scapularis ticks, our finding that transovarially-infected larvae effectively transmit B. miyamotoi should lead to refined tick-bite prevention messages.
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10
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Graham CB, Maes SE, Hojgaard A, Fleshman AC, Sheldon SW, Eisen RJ. A molecular algorithm to detect and differentiate human pathogens infecting Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae). Ticks Tick Borne Dis 2018; 9:390-403. [PMID: 29258802 PMCID: PMC6452875 DOI: 10.1016/j.ttbdis.2017.12.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/21/2017] [Accepted: 12/06/2017] [Indexed: 12/23/2022]
Abstract
The incidence and geographic range of tick-borne illness associated with Ixodes scapularis and Ixodes pacificus have dramatically increased in recent decades. Anaplasmosis, babesiosis, and Borrelia spirochete infections, including Lyme borreliosis, account for tens of thousands of reported cases of tick-borne disease every year. Assays that reliably detect pathogens in ticks allow investigators and public health agencies to estimate the geographic distribution of human pathogens, assess geographic variation in their prevalence, and evaluate the effectiveness of prevention strategies. As investigators continue to describe new species within the Borrelia burgdorferi sensu lato complex and to recognize some Ixodes-borne Borrelia species as human pathogens, assays are needed to detect and differentiate these species. Here we describe an algorithm to detect and differentiate pathogens in unfed I. scapularis and I. pacificus nymphs including Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi sensu stricto, Borrelia mayonii, and Borrelia miyamotoi. The algorithm comprises 5 TaqMan real-time polymerase chain reaction assays and 3 sequencing protocols. It employs multiple targets for each pathogen to optimize specificity, a gene target for I. scapularis and I. pacificus to verify tick-derived DNA quality, and a pan-Borrelia target to detect Borrelia species that may emerge as human disease agents in the future. We assess the algorithm's sensitivity, specificity, and performance on field-collected ticks.
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Affiliation(s)
- Christine B Graham
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Rd., Fort Collins, CO 80521, United States.
| | - Sarah E Maes
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Rd., Fort Collins, CO 80521, United States
| | - Andrias Hojgaard
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Rd., Fort Collins, CO 80521, United States
| | - Amy C Fleshman
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Rd., Fort Collins, CO 80521, United States
| | - Sarah W Sheldon
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Rd., Fort Collins, CO 80521, United States
| | - Rebecca J Eisen
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Rd., Fort Collins, CO 80521, United States
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