#Polymicrobial Nature of #Tick-Borne #Diseases (mBio, abstract)

[Source: mBio, full page: (LINK). Abstract, edited.]

Polymicrobial Nature of Tick-Borne Diseases

Santiago Sanchez-Vicente, Teresa Tagliafierro, James L. Coleman, Jorge L. Benach, Rafal Tokarz

Liise-anne Pirofski, Editor

DOI: 10.1128/mBio.02055-19



Tick-borne diseases have doubled in the last 12 years, and their geographic distribution has spread as well. The clinical spectrum of tick-borne diseases can range from asymptomatic to fatal infections, with a disproportionate incidence in children and the elderly. In the last few years, new agents have been discovered, and genetic changes have helped in the spread of pathogens and ticks. Polymicrobial infections, mostly in Ixodes scapularis, can complicate diagnostics and augment disease severity. Amblyomma americanum ticks have expanded their range, resulting in a dynamic and complex situation, possibly fueled by climate change. To document these changes, using molecular biology strategies for pathogen detection, an assessment of 12 microbes (9 pathogens and 3 symbionts) in three species of ticks was done in Suffolk County, New York. At least one agent was detected in 63% of I. scapularis ticks. Borrelia burgdorferi was the most prevalent pathogen (57% in adults; 27% in nymphs), followed by Babesia microti (14% in adults; 15% in nymphs), Anaplasma phagocytophilum (14% in adults; 2% in nymphs), Borrelia miyamotoi (3% in adults), and Powassan virus (2% in adults). Polymicrobial infections were detected in 22% of I. scapularis ticks, with coinfections of B. burgdorferi and B. microti (9%) and of B. burgdorferi and A. phagocytophilum (7%). Three Ehrlichia species were detected in 4% of A. americanum ticks. The rickettsiae constituted the largest prokaryotic biomass of all the ticks tested and included Rickettsia amblyommatis, Rickettsia buchneri, and Rickettsia montanensis. The high rates of polymicrobial infection in ticks present an opportunity to study the biological interrelationships of pathogens and their vectors.



Tick-borne diseases have increased in prevalence in the United States and abroad. The reasons for these increases are multifactorial, but climate change is likely to be a major factor. One of the main features of the increase is the geographic expansion of tick vectors, notably Amblyomma americanum, which has brought new pathogens to new areas. The clinical spectrum of tick-borne diseases can range from asymptomatic to fatal infections, with a disproportionate incidence in children and the elderly. In addition, new pathogens that are cotransmitted by Ixodes scapularis have been discovered and have led to difficult diagnoses and to disease severity. Of these, Borrelia burgdorferi, the agent of Lyme disease, continues to be the most frequently transmitted pathogen. However, Babesia microti, Borrelia miyamotoi (another spirochete), Anaplasma phagocytophilum, and Powassan virus are frequent cotransmitted agents. Polymicrobial infection has important consequences for the diagnosis and management of tick-borne diseases.

Keywords: Tick-borne diseases; Powassan virus; Borrelia burgorferi; Infectious diseases.


Essential Role of #Interferon Response in Containing #Human #Pathogenic #Bourbon Virus (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 25, Number 7—July 2019 / Research

Essential Role of Interferon Response in Containing Human Pathogenic Bourbon Virus

Jonas Fuchs, Tobias Straub, Maximilian Seidl, and Georg Kochs

Author affiliations: University of Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany



Bourbon virus (BRBV) is a recently discovered tick-transmitted viral pathogen that is prevalent in the Midwest and southern United States. Since 2014, zoonotic BRBV infections have been verified in several human cases of severe febrile illness, occasionally with fatal outcomes, indicating a possible public health threat. We analyzed the pathology of BRBV infection in mice and found a high sensitivity of the virus to the host interferon system. Infected standard laboratory mice did not show clinical signs or virus replication. However, in mice carrying defects in the type I and type II interferon system, the virus grew to high titers and caused severe pathology. In cell culture, BRBV was blocked by antiviral agents like ribavirin and favipiravir (T705). Our data suggest that persons having severe BRBV infection might have a deficiency in their innate immunity and could benefit from an already approved antiviral treatment.

Keywords: Arbovirus; Bourbon virus; Tick-borne infections; Viral pathogenesis; Antivirals; Interferons; Ribavirin; Favipiravir.


#Lyme #neuroborreliosis‐ clinical outcomes, #controversy, #pathogenesis, and polymicrobial #infections (Ann Neurol., abstract)

[Source: Annals of Neurology, full page: (LINK). Abstract, edited.]

Lyme neuroborreliosis‐ clinical outcomes, controversy, pathogenesis, and polymicrobial infections

Juan Carlos Garcia‐Monco MD, PhD, FAAN,  Jorge L. Benach PhD

First published: 10 December 2018 / DOI: https://doi.org/10.1002/ana.25389

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record.

Please cite this article as doi: 10.1002/ana.25389.



Lyme Borreliosis is the object of numerous misconceptions. In this review, we revisit the fundamental manifestations of neuroborreliosis (meningitis and cranial and radiculoneuritis) as these have withstood the test of time. We also discuss other manifestations that are less frequent. Stroke, as a manifestation of Lyme neuroborreliosis, is considered in the context of other infections. The summary of the literature regarding clinical outcomes of neuroborreliosis leads to its controversies. We also include new information on pathogenesis, and on the polymicrobial nature of tick‐borne diseases. In this way, we update the review that we wrote in this journal in 1995.

This article is protected by copyright. All rights reserved.

Keywords: Lyme’s Disease; Tick-borne diseases; Lyme Neuroborreliosis.


#Tickborne #Diseases — Confronting a Growing #Threat (N Engl J Med., excerpt)

[Source: The New England Journal of Medicine, full page: (LINK). Excerpt, edited.]


Tickborne Diseases — Confronting a Growing Threat

Catharine I. Paules, M.D., Hilary D. Marston, M.D., M.P.H., Marshall E. Bloom, M.D., and Anthony S. Fauci, M.D.


Every spring, public health officials prepare for an upsurge in vectorborne diseases. As mosquito-borne illnesses have notoriously surged in the Americas, the U.S. incidence of tickborne infections has risen insidiously, triggering heightened attention from clinicians and researchers.


This article was published on July 25, 2018, at NEJM.org.


Author Affiliations

From the Office of the Director, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Bethesda, MD (C.I.P., H.D.M., A.S.F.); and the Rocky Mountain Laboratories of the Intramural Research Program of NIAID, Hamilton, MT (M.E.B.).

Keywords: Emerging Diseases; Tick-borne diseases.


#Rickettsia helvetica in #Human-Parasitizing and Free-Living #Ixodes ricinus from Urban and Wild Green Areas in the Metropolitan City of #Rome, #Italy (Vector Borne Zoo Dis., abstract)

[Source: Vector-Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Rickettsia helvetica in Human-Parasitizing and Free-Living Ixodes ricinus from Urban and Wild Green Areas in the Metropolitan City of Rome, Italy

Scarpulla Manuela, Barlozzari Giulia, Salvato Laura, De Liberato Claudio, Lorenzetti Raniero, and Macrì Gladia

Published Online: 17 Apr 2018 / DOI: https://doi.org/10.1089/vbz.2017.2235



Rickettsia helvetica is an emerging human pathogen, belonging to the spotted fever group (SFG) rickettsiae, associated with generally aneruptive fever, meningitis, and sudden death in chronic perimyocarditis. In this study, we describe the detection of R. helvetica in human-parasitizing and free-living Ixodes ricinus from the Metropolitan City of Rome. The pathogen was found in a tick acquired by a woman in an urban park. The circulation of R. helvetica was further confirmed by its detection in free-living ticks from a wild green area. These findings demonstrate that urban as well as wild green areas can represent a risk of infection to humans by R. helvetica, with potentially severe sequelae. To the best of our knowledge, this is the first report of R. helvetica in the Lazio region. Large-scale studies are needed to evaluate and quantify the presence of R. helvetica and other SFG rickettsiae in the urban and periurban context and to assess the risk to humans and animals related to their frequentation.

Keywords:  Rickettsia Helvetica; Italy; Ticks.


Molecular #genomic characterization of #tick- and #human-derived #SFTS virus isolates from #SouthKorea

[Source: PLoS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]


Molecular genomic characterization of tick- and human-derived severe fever with thrombocytopenia syndrome virus isolates from South Korea

Seok-Min Yun , Su-Jin Park , Sun-Whan Park, WooYoung Choi, Hye Won Jeong, Young-Ki Choi , Won-Ja Lee

Published: September 22, 2017 / DOI: https://doi.org/10.1371/journal.pntd.0005893 / This is an uncorrected proof.




Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne viral disease caused by the SFTS virus (SFTSV) from Bunyaviridae that is endemic in East Asia. However, the genetic and evolutionary characteristics shared between tick- and human-derived Korean SFTSV strains are still limited.

Methodology/Principal findings

In this study we identify, for the first time, the genome sequence of a tick (Haemaphysalis longicornis)-derived Korean SFTSV strain (designated as KAGWT) and compare this virus with recent human SFTSV isolates to identify the genetic variations and relationships among SFTSV strains. The genome of the KAGWT strain is consistent with the described genome of other members of the genus Phlebovirus with 6,368 nucleotides (nt), 3,378 nt, and 1,746 nt in the Large (L), Medium (M) and Small (S) segments, respectively. Compared with other completely sequenced human-derived Korean SFTSV strains, the KAGWT strain had highest sequence identities at the nucleotide and deduced amino acid level in each segment with the KAGWH3 strain which was isolated from SFTS patient within the same region, although there is one unique amino acid substitution in the Gn protein (A66S). Phylogenetic analyses of complete genome sequences revealed that at least four different genotypes of SFTSV are co-circulating in South Korea, and that the tick- and human-derived Korean SFTSV strains (genotype B) are closely related to one another. Although we could not detect reassortant, which are commonly observed in segmented viruses, further large-scale surveillance and detailed genomic analysis studies are needed to better understand the molecular epidemiology, genetic diversity, and evolution of SFTSV.


Full-length sequence analysis revealed a clear association between the genetic origins of tick- and human-derived SFTSV strains. While the most prevalent Korean SFTSV is genotype B, at least four different genotypes of SFTSV strains are co-circulating in South Korea. These findings provide information regarding the molecular epidemiology, genetic diversity, and evolution of SFTSV in East Asia.


Author summary

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne viral disease caused by the SFTS virus (SFTSV). During entomological surveillance of SFTSV infection in Korean ticks collected from SFTS outbreak areas, we isolated a single SFTSV strain which we designated KAGWT. In addition, we isolated three SFTSVs from human patients with typical SFTS symptoms. In this study, we report the genomic sequences of each of these isolates and compare the genetic and evolutionary characteristics between tick- and human-derived Korean SFTSV isolates. Genetic and phylogenetic analyses of these sequences revealed that the tick-derived Korean SFTSV strain is clustered into genotype B, the most prevalent genotype in South Korea, and was closely related to other SFTSV in the same group. Furthermore, our results show that at least four different genotypes of SFTSV strains are co-circulating in South Korea.


Citation: Yun S-M, Park S-J, Park S-W, Choi W, Jeong HW, Choi Y-K, et al. (2017) Molecular genomic characterization of tick- and human-derived severe fever with thrombocytopenia syndrome virus isolates from South Korea. PLoS Negl Trop Dis 11(9): e0005893. https://doi.org/10.1371/journal.pntd.0005893

Editor: Masayuki Saijo, National Institute of Infectious Disease, JAPAN

Received: May 10, 2017; Accepted: August 22, 2017; Published: September 22, 2017

Copyright: © 2017 Yun et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files, and deposited in the GenBank database with accession numbers KY273136-KY273138 and KY789433-KY789441.

Funding: This research was funded by intramural grants of the Korea National Research Institute of Health (grant numbers: 2014-ND53001 and 2017-NI53002-00) and a grant of the Korea Health Industry Development Institute (grant number: HI15C2817). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: STFS; South Korea.


#Serologic #Evidence of #Powassan Virus #Infection in Patients with Suspected #Lyme Disease (@CDC_EIDjournal, abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 23, Number 8—August 2017 / Dispatch

Serologic Evidence of Powassan Virus Infection in Patients with Suspected Lyme Disease

Holly M. Frost1, Anna M. Schotthoefer, Angela M. Thomm, Alan P. Dupuis, Sue C. Kehl, Laura D. Kramer, Thomas R. Fritsche, Yvette A. Harrington, and Konstance K. Knox

Author affiliations: Marshfield Clinic Research Foundation, Marshfield, Wisconsin, USA (H.M. Frost, A.M. Schotthoefer, T.R. Fritsche); Coppe Laboratories, Waukesha, Wisconsin, USA (A.M. Thomm, Y.A. Harrington, K.K. Knox); New York State Department of Health, Slingerlands, New York, USA (A.P. Dupuis II, L.D. Kramer); Medical College of Wisconsin, Milwaukee, Wisconsin, USA (S.C. Kehl)



Powassan virus (POWV) lineage II is an emerging tickborne flavivirus with an unknown seroprevalence in humans. In a Lyme disease–endemic area, we examined the seroreactivity to POWV in 2 patient cohorts and described the clinical features of the POWV-seroreactive patients. POWV disease might be less neuroinvasive than previously thought.

Keywords: Powassan Encephalitis Virus; Tick Borne Infections; Ticks; Lyme Disease; Flavivirus.