The Blacklegged Tick, Ixodes scapularis : An Increasing Public Health Concern

Eisen, Rebecca J.; Eisen, Lars

doi:10.1016/j.pt.2017.12.006

Cited by 296 publications

(234 citation statements)

References 121 publications

Supporting

Mentioning

228

Contrasting

Unclassified

Order By: Relevance

“…POWV is emerging, as increasing numbers of cases have been diagnosed over the past decade 229 and up to 3-5% of I. scapularis ticks isolated in certain parts of the United States now test positive for POWV 230,231 . Moreover, seroprevalence rates of POWV infection in other mammals (for example, white-tailed deer) are rising and may be associated with the expanded range of I. scapularis in the United States 232 . Thus, an abundance of evidence suggests that POWV is an emerging flavivirus threat, which has triggered the development of countermeasures to minimize severe disease 233 .…”

Section: Ilheus Virusmentioning

confidence: 99%

The continued threat of emerging flaviviruses

Pierson

Diamond²

2020

Nat Microbiol

724

627

View full text Add to dashboard Cite

F laviviruses are single-stranded RNA viruses vectored principally by arthropods that cause severe illnesses in humans. The extensive global spread and epidemic transmission of flaviviruses during the last seven decades has been remarkable. The mosquito-borne dengue viruses (DENV) infect an estimated 400 million humans each year; more than a quarter of the world's population lives in areas where DENV is now endemic 1 . By comparison, only sporadic DENV epidemics were documented before the Second World War 2 . The introductions of West Nile (WNV) and Zika (ZIKV) viruses into the Western Hemisphere was followed by rapid geographical spread, large numbers of human infections and considerable morbidity 3,4 . Ongoing yellow fever virus (YFV) transmission and its encroachment on urban environments, despite the existence of an effective vaccine, poses a serious public health challenge 5-7 . Other flaviviruses present ongoing health risks or are beginning to emerge in different parts of the world, including Japanese encephalitis virus (JEV), tick-borne encephalitis virus (TBEV) and Usutu virus (USUV).The epidemic potential of flaviviruses reflects many factors related to the unique characteristics of their insect vectors, the consequences of poorly planned urbanization that creates ideal arthropod breeding habitats, the geographical expansion of vectors, changing environmental conditions and extensive global travel 8,9 . Beyond arthropods and humans, flaviviruses are also known to infect a wide array of animal species and can be important veterinary pathogens that threaten economically important domesticated animals 10-14 . These vertebrate animal hosts may constitute important stable reservoirs and contribute to defining conditions that support the introduction of new viral species and transmission among humans 15 . The continued threat of flavivirus emergence and re-emergence highlights a need for a detailed fundamental understanding of the biology of these viruses, the immune responses that can contain them and the possible countermeasures that can blunt their impact on public health should new outbreaks occur. Flavivirus structure and replicationFlaviviruses are small (~50 nm) spherical virus particles that incorporate a single genomic RNA of positive-sense polarity encoding three structural and seven non-structural proteins (Fig. 1a). Our knowledge of the biology of flaviviruses has advanced considerably with the availability of high-resolution structures of viral structural proteins and of virions at different stages of the replication cycle or in complex with antibodies or host factors 16 . Crystal structures of the enzymatic non-structural proteins also have been solved, accelerating advances in an understanding of virus replication and pathogenesis [17][18][19] and enabling structure-guided drug discovery, as reviewed elsewhere 20 .Virion structure and morphogenesis. Flaviviruses are assembled using three viral structural proteins (C, prM and E), a host lipid envelope and the viral genomic RNA. The structure of ...

show abstract

Section: Ilheus Virusmentioning

confidence: 99%

The continued threat of emerging flaviviruses

Pierson

Diamond²

2020

Nat Microbiol

724

627

View full text Add to dashboard Cite

show abstract

“…Thus, other contributing factors must also be taken into account. The dramatic territory expansion of an important competent tick species, Ixodes scapularis, seen over the past decade is probably the most important contributing factor (171).…”

Section: Epidemiologymentioning

confidence: 99%

Tick-Borne Flaviviruses, with a Focus on Powassan Virus

2018

View full text Add to dashboard Cite

SUMMARYThe tick-borne pathogen Powassan virus is a rare cause of encephalitis in North America and the Russian Far East. The number of documented cases described since the discovery of Powassan virus in 1958 may be <150, although detection of cases has increased over the past decade. In the United States, the incidence of Powassan virus infections expanded from the estimated 1 case per year prior to 2005 to 10 cases per year during the subsequent decade. The increased detection rate may be associated with several factors, including enhanced surveillance, the availability of improved laboratory diagnostic methods, the expansion of the vector population, and, perhaps, altered human activities that lead to more exposure. Nonetheless, it remains unclear whether Powassan virus is indeed an emerging threat or if enzootic cycles in nature remain more-or-less stable with periodic fluctuations of host and vector population sizes. Despite the low disease incidence, the approximately 10% to 15% case fatality rate of neuroinvasive Powassan virus infection and the temporary or prolonged sequelae in >50% of survivors make Powassan virus a medical concern requiring the attention of public health authorities and clinicians. The medical importance of Powassan virus justifies more research on developing specific and effective treatments and prevention and control measures.

show abstract

“…Lyme disease (LD) is the most common vector‐borne illness in North America and Europe, with an estimated 300,000 new human cases occurring annually in the United States (Hinckley et al, ; Steere et al, ). In North America, LD is primarily caused by the spirochete Borrelia burgdorferi sensu stricto (hereafter B. burgdorferi ), which is transmitted by Ixodes ticks and maintained in various vertebrate reservoir hosts (mainly mammals and birds; Brisson, Drecktrah, Eggers, & Samuels, ; Eisen & Eisen, ). Following tick bites, the spirochetes spread from the skin of inoculation site to multiple tissues and organs via the bloodstream (Steere et al, ).…”

Section: Introductionmentioning

confidence: 99%

Blood treatment of Lyme borreliae demonstrates the mechanism of CspZ ‐mediated complement evasion to promote systemic infection in vertebrate hosts

Marcinkiewicz

Dupuis

Zamba‐Campero

et al. 2019

Cellular Microbiology

View full text Add to dashboard Cite

Lyme disease, caused by the spirochete Borrelia burgdorferi, is the most common vector‐borne disease in the United States and Europe. The spirochetes are transmitted from mammalian and avian reservoir hosts to humans via ticks. Following tick bites, spirochetes colonize the host skin and then disseminate haematogenously to various organs, a process that requires this pathogen to evade host complement, an innate immune defence system. CspZ, a spirochete surface protein, facilitates resistance to complement‐mediated killing in vitro by binding to the complement regulator, factor H (FH). Low expression levels of CspZ in spirochetes cultivated in vitro or during initiation of infection in vivo have been a major hurdle in delineating the role of this protein in pathogenesis. Here, we show that treatment of B. burgdorferi with human blood induces CspZ production and enhances resistance to complement. By contrast, a cspZ‐deficient mutant and a strain that expressed an FH‐nonbinding CspZ variant were impaired in their ability to cause bacteraemia and colonize tissues of mice or quail; virulence of these mutants was however restored in complement C3‐deficient mice. These novel findings suggest that FH binding to CspZ facilitates B. burgdorferi complement evasion in vivo and promotes systemic infection in vertebrate hosts.

show abstract

The Blacklegged Tick, Ixodes scapularis : An Increasing Public Health Concern

Cited by 296 publications

References 121 publications

The continued threat of emerging flaviviruses

The continued threat of emerging flaviviruses

Tick-Borne Flaviviruses, with a Focus on Powassan Virus

Blood treatment of Lyme borreliae demonstrates the mechanism of CspZ ‐mediated complement evasion to promote systemic infection in vertebrate hosts

Contact Info

Product

Resources

About