Incorporating tick feeding behaviour into R0 for tick-borne pathogens.

Incorporating tick feeding behaviour into R0 for tick-borne pathogens. Theor Popul Biol. 2019 Nov 12;: Authors: Johnstone-Robertson SP, Diuk-Wasser MA, Davis SA Abstract Tick-borne pathogens pose a considerable disease burden in Europe and North America, where increasing numbers of human cases and the emergence of new tick-borne pathogens has renewed interest in resolving the mechanisms underpinning their geographical distribution and abundance. For Borrelia burgdorferi and tick-borne encephalitis (TBE) virus, transmission of infection from one generation of ticks to another occurs when older nymphal ticks infect younger larval ticks feeding on the same host, either indirectly via systemic infection of the vertebrate host or directly when feeding in close proximity. Here, expressions for the basic reproduction number, R0, and the related tick type-reproduction number, T, are derived that account for the observation that larval and nymphal ticks tend to aggregate on the same minority of hosts, a tick feeding behaviour known as co-aggregation. The pattern of tick blood meals is represented as a directed, acyclic, bipartite contact network, with individual vertebrate hosts having in-degree, kin, and out-degree, kout, that respectively represent cumulative counts of nymphal and larval ticks fed over the lifetime of the host. The in- and out-degree are not independent when co-aggregation occurs such that [Formula: see text] where 〈.〉 indicates expected va...
Source: Theoretical Population Biology - Category: Biology Authors: Tags: Theor Popul Biol Source Type: research

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(CNN/CBS) — The climate crisis is making us more vulnerable to ticks in an unprecedented and growing threat to public health, according to a new report. Bacterial and protozoan tick-borne diseases doubled in the United States between 2004 and 2016, the report notes, and in 2017, more than 90% of the 60,000 vector-borne diseases in the United States were linked to these particular bloodsucking bugs. The warmer temperatures brought by the climate crisis, in addition to ecological changes and reforestation, have extended the bugs’ range into regions that had not seen certain types of ticks for many decades, if eve...
Source: WBZ-TV - Breaking News, Weather and Sports for Boston, Worcester and New Hampshire - Category: Consumer Health News Authors: Tags: Boston News Health Syndicated CBSN Boston Lone Star Tick ticks Source Type: news
der F Abstract Introduction: Despite advancements in diagnostic capabilities and the availability of effective antimicrobial agents, community-acquired infections of the central nervous system (CNS) are still associated with high mortality rates. Aim: To assess the epidemiological and clinical characteristics of community-acquired CNS infections treated in the West Pannonian region between 2010 and 2016. Method: Clinical data of 176 patients were retrospectively analysed in two age cohorts: 15 to 65 and more than 65 years of age. Results: Neuroinfections were found to be bacterial in 81, viral in 91, parasitic in ...
Source: Orvosi Hetilap - Category: General Medicine Authors: Tags: Orv Hetil Source Type: research
Authors: Brodziński S, Nasierowski T Abstract In the second part of the article case reports of three patients were presented. All patientswere treated for Borrelia infection and all of them developed psychotic disorders. History of each patient was different, as well as the probability of causal relationship between neuroborreliosis and psychosis. The first case concerns a female patient with no former psychiatric history, who developed psychotic episode secondary to neuroborreliosis. Psychotic disorders resolved after antibiotic treatment. In the second case, a male patient was previously twice hospitalized in p...
Source: Psychiatria Polska - Category: Psychiatry Tags: Psychiatr Pol Source Type: research
Vector-Borne and Zoonotic Diseases, Ahead of Print.
Source: Vector-Borne and Zoonotic Diseases - Category: Infectious Diseases Authors: Source Type: research
oor Ticks are vectors of several pathogens that can be transmitted to humans and their geographic ranges are expanding. The exposure of ticks to new hosts in a rapidly changing environment is likely to further increase the prevalence and diversity of tick-borne diseases. Although ticks are known to transmit bacteria and viruses, most studies of tick-borne disease have focused upon Lyme disease, which is caused by infection with Borrelia burgdorferi. Until recently, ticks were considered as the vectors of a few viruses that can infect humans and animals, such as Powassan, Tick-Borne Encephalitis and Crimean–Co...
Source: Viruses - Category: Virology Authors: Tags: Review Source Type: research
Publication date: Available online 22 April 2019Source: Ticks and Tick-borne DiseasesAuthor(s): Pavel Švec, Václav Hönig, Dana Zubriková, Maria Wittmann, Kurt Pfister, Libor GrubhofferAbstractResearch projects in the field of eco-epidemiology of tick-borne diseases often require extensive sampling of arthropod vectors in the field. The aim of our study was to use geographical information systems (GIS) to select appropriate sampling sites of Ixodes ricinus ticks in central European habitat for further ecological studies of vector-borne pathogens (tick-borne encephalitis virus and Borrelia burgdorfe...
Source: Ticks and Tick borne Diseases - Category: Zoology Source Type: research
Authors: Boulanger N, Boyer P, Talagrand-Reboul E, Hansmann Y Abstract Ticks are a major group of arthropod vectors, characterized by the diversity of pathogens they transmit, by their impact on human and animal health, and by their socioeconomic implication especially in countries of the Southern Hemisphere. In Europe, Ixodes is the most important tick due to its wide distribution in the ecosystems and the variety of transmitted pathogens, in particular Borrelia (responsible for Lyme borreliosis), but also the tick-borne encephalitis virus. Their increased presence in the environment since the beginning of the 20t...
Source: Medecine et Maladies Infectieuses - Category: Infectious Diseases Tags: Med Mal Infect Source Type: research
In this study, the prevalence of antibodies against two Babesia spp. was investigated in a cohort of patients that were seropositive for Borrelia (B.) burgdorferi sensu lato (s.l.). Data were compared to a control group of healthy individuals. Sera were collected from 283 individuals residing in the southernmost region of Sweden, Skåne County. Almost one third of the sera were from patients with a confirmed seropositive reaction against B. burgdorferi s.l. All sera samples were assessed for IgG antibodies against Babesia (Ba.) microti and Ba. divergens by indirect fluorescent antibody (IFA) assays. Seropositive IgG t...
Source: Ticks and Tick borne Diseases - Category: Zoology Source Type: research
Publication date: July 2018Source: Ticks and Tick-borne Diseases, Volume 9, Issue 5Author(s): Mateusz Markowicz, Anna-Margarita Schötta, Michael Kundi, Petra Bogovič, Katarina Ogrinc, Franc Strle, Gerold StanekAbstractThe aims of the study were to determine and compare the concentration of CXCL13 in cerebrospinal fluid (CSF) of patients with Lyme neuroborreliosis (LNB) and various other neurological disorders applying a Luminex based assay and ELISA, and to find factors associated with CXCL13 concentration. CSF samples obtained from four clinically well-defined groups of patients (proven LNB, suspected LNB, tick-born...
Source: Ticks and Tick borne Diseases - Category: Zoology Source Type: research
Publication date: July 2018Source: Ticks and Tick-borne Diseases, Volume 9, Issue 5Author(s): Vivian Kjelland, Katrine M. Paulsen, Rikke Rollum, Andrew Jenkins, Snorre Stuen, Arnulf Soleng, Kristin S. Edgar, Heidi H. Lindstedt, Kirsti Vaino, Moustafa Gibory, Åshild K. AndreassenAbstractThe aim of this study was to determine the occurrence of tick-borne pathogens of medical importance in questing ticks collected from five recreationally used islands along the Norwegian coastline. Furthermore, since coinfection may affect the disease severity, this study aimed to determine the extent of coinfection in individual ticks ...
Source: Ticks and Tick borne Diseases - Category: Zoology Source Type: research
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