-
Infectious Disease Clinics of North... Mar 2019Rickettsia are small, obligately intracellular, gram-negative bacilli. They are distributed among a variety of hematophagous arthropod vectors and cause illness... (Review)
Review
Rickettsia are small, obligately intracellular, gram-negative bacilli. They are distributed among a variety of hematophagous arthropod vectors and cause illness throughout the world. Rickettsioses present as an acute undifferentiated febrile illness and are often accompanied by headache, myalgias, and malaise. Cutaneous manifestations include rash and eschar, which both occur at varying incidence depending on the infecting species. Serology is the mainstay of diagnosis, and the indirect immunofluorescence assay is the test of choice. Reactive antibodies are seldom present during early illness, so testing should be performed on both acute-phase and convalescent-phase sera. Doxycycline is the treatment of choice.
Topics: Animals; Anti-Bacterial Agents; Arthropod Vectors; Doxycycline; Humans; Rickettsia Infections; Rocky Mountain Spotted Fever
PubMed: 30712763
DOI: 10.1016/j.idc.2018.10.010 -
Current Issues in Molecular Biology 2021Lyme disease are obligately parasitic, tick- transmitted, invasive, persistent bacterial pathogens that cause disease in humans and non-reservoir vertebrates primarily... (Review)
Review
Lyme disease are obligately parasitic, tick- transmitted, invasive, persistent bacterial pathogens that cause disease in humans and non-reservoir vertebrates primarily through the induction of inflammation. During transmission from the infected tick, the bacteria undergo significant changes in gene expression, resulting in adaptation to the mammalian environment. The organisms multiply and spread locally and induce inflammatory responses that, in humans, result in clinical signs and symptoms. virulence involves a multiplicity of mechanisms for dissemination and colonization of multiple tissues and evasion of host immune responses. Most of the tissue damage, which is seen in non-reservoir hosts, appears to result from host inflammatory reactions, despite the low numbers of bacteria in affected sites. This host response to the Lyme disease can cause neurologic, cardiovascular, arthritic, and dermatologic manifestations during the disseminated and persistent stages of infection. The mechanisms by which a paucity of organisms (in comparison to many other infectious diseases) can cause varied and in some cases profound inflammation and symptoms remains mysterious but are the subjects of diverse ongoing investigations. In this review, we provide an overview of virulence mechanisms and determinants for which roles have been demonstrated , primarily in mouse models of infection.
Topics: Animals; Arthropod Vectors; Borrelia; Disease Models, Animal; Disease Susceptibility; Gene Expression Regulation, Bacterial; Host-Pathogen Interactions; Humans; Lyme Disease; Ticks; Virulence; Virulence Factors
PubMed: 33353871
DOI: 10.21775/cimb.042.473 -
Current Issues in Molecular Biology 2021Lyme disease (Lyme borreliosis) is a tick-borne, zoonosis of adults and children caused by genospecies of the sensu lato complex. The ailment, widespread throughout the...
Lyme disease (Lyme borreliosis) is a tick-borne, zoonosis of adults and children caused by genospecies of the sensu lato complex. The ailment, widespread throughout the Northern Hemisphere, continues to increase globally due to multiple environmental factors, coupled with increased incursion of humans into habitats that harbor the spirochete. sensu lato is transmitted by ticks from the complex. In North America, causes nearly all infections; in Europe, and are most associated with human disease. The spirochete's unusual fragmented genome encodes a plethora of differentially expressed outer surface lipoproteins that play a seminal role in the bacterium's ability to sustain itself within its enzootic cycle and cause disease when transmitted to its incidental human host. Tissue damage and symptomatology (i.e., clinical manifestations) result from the inflammatory response elicited by the bacterium and its constituents. The deposition of spirochetes into human dermal tissue generates a local inflammatory response that manifests as erythema migrans (EM), the hallmark skin lesion. If treated appropriately and early, the prognosis is excellent. However, in untreated patients, the disease may present with a wide range of clinical manifestations, most commonly involving the central nervous system, joints, or heart. A small percentage (~10%) of patients may go on to develop a poorly defined fibromyalgia-like illness, post-treatment Lyme disease (PTLD) unresponsive to prolonged antimicrobial therapy. Below we integrate current knowledge regarding the ecologic, epidemiologic, microbiologic, and immunologic facets of Lyme disease into a conceptual framework that sheds light on the disorder that healthcare providers encounter.
Topics: Animals; Arthropod Vectors; Borrelia burgdorferi; Disease Management; Disease Susceptibility; Host-Pathogen Interactions; Humans; Life Cycle Stages; Lyme Disease; Organ Specificity; Ticks
PubMed: 33303701
DOI: 10.21775/cimb.042.333 -
Nature Reviews. Microbiology Oct 2020Borrelia burgdorferi is the causative agent of Lyme disease and is transmitted to vertebrate hosts by Ixodes spp. ticks. The spirochaete relies heavily on its arthropod... (Review)
Review
Borrelia burgdorferi is the causative agent of Lyme disease and is transmitted to vertebrate hosts by Ixodes spp. ticks. The spirochaete relies heavily on its arthropod host for basic metabolic functions and has developed complex interactions with ticks to successfully colonize, persist and, at the optimal time, exit the tick. For example, proteins shield spirochaetes from immune factors in the bloodmeal and facilitate the transition between vertebrate and arthropod environments. On infection, B. burgdorferi induces selected tick proteins that modulate the vector gut microbiota towards an environment that favours colonization by the spirochaete. Additionally, the recent sequencing of the Ixodes scapularis genome and characterization of tick immune defence pathways, such as the JAK-STAT, immune deficiency and cross-species interferon-γ pathways, have advanced our understanding of factors that are important for B. burgdorferi persistence in the tick. In this Review, we summarize interactions between B. burgdorferi and I. scapularis during infection, as well as interactions with tick gut and salivary gland proteins important for establishing infection and transmission to the vertebrate host.
Topics: Animals; Arachnid Vectors; Arthropod Proteins; Borrelia burgdorferi; Gene Expression Regulation; Genome; Host-Pathogen Interactions; Humans; Intestines; Ixodes; Lyme Disease; Protein-Tyrosine Kinases; STAT Transcription Factors; Salivary Glands; Salivary Proteins and Peptides; Signal Transduction
PubMed: 32651470
DOI: 10.1038/s41579-020-0400-5 -
Infectious Diseases of Poverty May 2023Climate change presents an imminent threat to almost all biological systems across the globe. In recent years there have been a series of studies showing how changes in... (Review)
Review
BACKGROUND
Climate change presents an imminent threat to almost all biological systems across the globe. In recent years there have been a series of studies showing how changes in climate can impact infectious disease transmission. Many of these publications focus on simulations based on in silico data, shadowing empirical research based on field and laboratory data. A synthesis work of empirical climate change and infectious disease research is still lacking.
METHODS
We conducted a systemic review of research from 2015 to 2020 period on climate change and infectious diseases to identify major trends and current gaps of research. Literature was sourced from Web of Science and PubMed literary repositories using a key word search, and was reviewed using a delineated inclusion criteria by a team of reviewers.
RESULTS
Our review revealed that both taxonomic and geographic biases are present in climate and infectious disease research, specifically with regard to types of disease transmission and localities studied. Empirical investigations on vector-borne diseases associated with mosquitoes comprised the majority of research on the climate change and infectious disease literature. Furthermore, demographic trends in the institutions and individuals published revealed research bias towards research conducted across temperate, high-income countries. We also identified key trends in funding sources for most resent literature and a discrepancy in the gender identities of publishing authors which may reflect current systemic inequities in the scientific field.
CONCLUSIONS
Future research lines on climate change and infectious diseases should considered diseases of direct transmission (non-vector-borne) and more research effort in the tropics. Inclusion of local research in low- and middle-income countries was generally neglected. Research on climate change and infectious disease has failed to be socially inclusive, geographically balanced, and broad in terms of the disease systems studied, limiting our capacities to better understand the actual effects of climate change on health.
Topics: Animals; Humans; Climate Change; Mosquito Vectors; Communicable Diseases; Culicidae; Forecasting
PubMed: 37194092
DOI: 10.1186/s40249-023-01102-2 -
Viruses Sep 2019Mosquito-specific viruses (MSVs) are a subset of insect-specific viruses that are found to infect mosquitoes or mosquito derived cells. There has been an increase in... (Review)
Review
Mosquito-specific viruses (MSVs) are a subset of insect-specific viruses that are found to infect mosquitoes or mosquito derived cells. There has been an increase in discoveries of novel MSVs in recent years. This has expanded our understanding of viral diversity and evolution but has also sparked questions concerning the transmission of these viruses and interactions with their hosts and its microbiome. In fact, there is already evidence that MSVs interact with the immune system of their host. This is especially interesting, since mosquitoes can be infected with both MSVs and arthropod-borne (arbo) viruses of public health concern. In this review, we give an update on the different MSVs discovered so far and describe current data on their transmission and interaction with the mosquito immune system as well as the effect MSVs could have on an arboviruses-co-infection. Lastly, we discuss potential uses of these viruses, including vector and transmission control.
Topics: Animals; Arbovirus Infections; Arboviruses; Culicidae; Host-Pathogen Interactions; Insect Viruses; Mosquito Vectors
PubMed: 31533367
DOI: 10.3390/v11090873 -
Vector Borne and Zoonotic Diseases... Jan 2017Borrelia species fall into two groups, the Borrelia burgdorferi sensu lato (Bbsl) complex, the cause of Lyme borreliosis (also known as Lyme disease), and the relapsing... (Review)
Review
Borrelia species fall into two groups, the Borrelia burgdorferi sensu lato (Bbsl) complex, the cause of Lyme borreliosis (also known as Lyme disease), and the relapsing fever group. Both groups exhibit inter- and intraspecies diversity and thus have variations in both clinical presentation and diagnostic approaches. A further layer of complexity is derived from the fact that ticks may carry multiple infectious agents and are able to transmit them to the host during blood feeding, with potential overlapping clinical manifestations. Besides this, pathogens like Borrelia have developed strategies to evade the host immune system, which allows them to persist within the host, including humans. Diagnostics can be applied at different times during the clinical course and utilize sample types, each with their own advantages and limitations. These differing methods should always be considered in conjunction with potential exposure and compatible clinical features. Throughout this review, we aim to explore different approaches providing the reader with an overview of methods appropriate for various situations. This review will cover human pathogenic members of Bbsl and relapsing fever borreliae, including newly recognized Borrelia miyamotoi spirochetes.
Topics: Animals; Arthropod Vectors; Borrelia; Humans; Lyme Disease; Relapsing Fever; Ticks
PubMed: 28055580
DOI: 10.1089/vbz.2016.1962 -
Virologica Sinica Feb 2018Ticks are important vectors for the transmission of pathogens including viruses. The viruses carried by ticks also known as tick-borne viruses (TBVs), contain a large... (Review)
Review
Ticks are important vectors for the transmission of pathogens including viruses. The viruses carried by ticks also known as tick-borne viruses (TBVs), contain a large group of viruses with diverse genetic properties and are concluded in two orders, nine families, and at least 12 genera. Some members of the TBVs are notorious agents causing severe diseases with high mortality rates in humans and livestock, while some others may pose risks to public health that are still unclear to us. Herein, we review the current knowledge of TBVs with emphases on the history of virus isolation and identification, tick vectors, and potential pathogenicity to humans and animals, including assigned species as well as the recently discovered and unassigned species. All these will promote our understanding of the diversity of TBVs, and will facilitate the further investigation of TBVs in association with both ticks and vertebrate hosts.
Topics: Animals; Arthropod Vectors; Disease Transmission, Infectious; Humans; Tick-Borne Diseases; Ticks; Virus Diseases; Viruses
PubMed: 29536246
DOI: 10.1007/s12250-018-0019-0 -
Trends in Parasitology Aug 2021Although Rickettsia species are molecularly detected among a wide range of arthropods, vector competence becomes an imperative aspect of understanding the... (Review)
Review
Although Rickettsia species are molecularly detected among a wide range of arthropods, vector competence becomes an imperative aspect of understanding the ecoepidemiology of these vector-borne diseases. The synergy between vector homeostasis and rickettsial invasion, replication, and release initiated within hours (insects) and days (ticks) permits successful transmission of rickettsiae. Uncovering the molecular interplay between rickettsiae and their vectors necessitates examining the multifaceted nature of rickettsial virulence and vector infection tolerance. Here, we highlight the biological differences between tick- and insect-borne rickettsiae and the factors facilitating the incidence of rickettsioses. Untangling the complex relationship between rickettsial genetics, vector biology, and microbial interactions is crucial in understanding the intricate association between rickettsiae and their vectors.
Topics: Animals; Arthropod Vectors; Host-Pathogen Interactions; Rickettsia
PubMed: 34162522
DOI: 10.1016/j.pt.2021.05.008 -
Viruses Nov 2014The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are... (Review)
Review
The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are significant human or agricultural pathogens. The viruses within the Orthobunyavirus, Nairovirus, and Phlebovirus genera are transmitted by hematophagous arthropods, such as mosquitoes, midges, flies, and ticks, and their associated arthropods not only serve as vectors but also as virus reservoirs in many cases. This review presents an overview of several important emerging or re-emerging bunyaviruses and describes what is known about bunyavirus-vector interactions based on epidemiological, ultrastructural, and genetic studies of members of this virus family.
Topics: Animals; Arthropod Vectors; Arthropods; Bunyaviridae Infections; Host-Pathogen Interactions; Humans; Orthobunyavirus
PubMed: 25402172
DOI: 10.3390/v6114373