A 117-year retrospective analysis of Pennsylvania tick community dynamics.

BACKGROUND: Tick-borne diseases have been increasing at the local, national, and global levels. Researchers studying ticks and tick-borne diseases need a thorough knowledge of the pathogens, vectors, and epidemiology of disease spread. Both active and passive surveillance approaches are typically used to estimate tick population size and risk of tick encounter. Our data consists of a composite of active and long-term passive surveillance, which has provided insight into spatial variability and temporal dynamics of ectoparasite communities and identified rarer tick species. We present a retrospective analysis on compiled data of ticks from Pennsylvania over the last 117 years. METHODS: We compiled data from ticks collected during tick surveillance research, and from citizen-based submissions. The majority of the specimens were submitted by citizens. However, a subset of the data was collected through active methods (flagging or dragging, or removal of ticks from wildlife). We analyzed all data from 1900-2017 for tick community composition, host associations, and spatio-temporal dynamics. RESULTS: In total there were 4491 submission lots consisting of 7132 tick specimens. Twenty-four different species were identified, with the large proportion of submissions represented by five tick species. We observed a shift in tick community composition in which the dominant species of tick (Ixodes cookei) was overtaken in abundance by Dermacentor variabilis in the early 1990s and then replaced in abundance by I. scapularis. We analyzed host data and identified overlaps in host range amongst tick species. CONCLUSIONS: We highlight the importance of long-term passive tick surveillance in investigating the ecology of both common and rare tick species. Information on the geographical distribution, host-association, and seasonality of the tick community can help researchers and health-officials to identify high-risk areas.

The Discovery of Q Fever and Its Cause.

An outbreak of a febrile illness among workers in a slaughterhouse in Brisbane, Australia led E.H. Derrick to discover a new infection, which he labeled Q fever. Almost simultaneously, investigators in Montana discovered a new organism in ticks that caused fever in guinea pigs. Eventually, investigators found that the Q fever and tick microbes were identical. Outbreaks of Q fever occurred in laboratories, and epidemics of it affected both Axis and Allied troops in Europe during World War II, but it was only afterwards that an explanation emerged about what the major reservoir of the organism was and how infection was most commonly transmitted to animals and humans.

The Current Status of Ticks in Turkey: A 100-Year Period Review from 1916 to 2016.

Environmental and bio-ecological changes, some administrative and political mistakes, and global warming seriously affect the behaviors of ticks in Turkey and globally. The global public sensitivity toward tick infestations has increased along with increases in tick-borne diseases (TBDs). Recently, the World Health Organization (WHO) developed a new political concept, "One Health," for specific struggle strategies against tick infestations and TBDs. To highlight the importance of the issue, the WHO had declared the year 2015 for vector-borne diseases and adopted the slogan "small bites big threat". In global struggle strategies, the epidemiological aspects and dynamics of increasing tick populations and their effects on the incidence of the TBDs mainly with zoonotic characteristics have been specifically targeted. In Turkey, during the last century, approximately 47 tick species, including eight soft and 39 hard tick species in three and six genera belonging to Argasidae and Ixodidae, respectively, had already been reported. In this article, the recorded tick species, regional infestations, and medical and veterinary importance in Turkey were chronologically reviewed based on a 100-year period between 1916 and 2016.

Parasitism of prehistoric humans and companion animals from Antelope Cave, Mojave County, northwest Arizona.

Previously, we reported a tick recovered from Antelope Cave in extreme northwest Arizona. Further analyses of coprolites from Antelope Cave revealed additional parasitological data from coprolites of both human and canid origin. A second tick was found. This site is the only archaeological locality where ticks have been recovered. We also discovered an acanthocephalan in association with Enterobius vermicularis eggs in the same coprolite. This association shows that the coprolite was deposited by a human. This discovery expands our knowledge of the range of prehistoric acanthocephalan infection. In addition, findings from canid coprolites of Trichuris vulpis are reported. This is the first published discovery of T. vulpis from a North American archaeological context. The close association of dogs with humans at Ancestral Puebloan (Anasazi) sites raises the potential that zoonotic parasites were transferred to the human population. The archaeological occupation is associated with the Ancestral Pueblo culture 1,100 yr ago.

Heartwater: an abridged historical account.

Heartwater was first recognised and recorded in South Africa as early as 1838. Since then the disease has been described from almost all the countries in Africa south of the Sahara, from certain islands around Africa and from a number of islands in the Caribbean. Most of the research on the disease, at least until fairly recently, was conducted in South Africa. Progress in research on the disease has been slow but a few important findings are highlighted in this paper.

A tick from a prehistoric Arizona coprolite.

Ticks have never been reported in archaeological analyses. Here, we present the discovery of a tick from a coprolite excavated from Antelope Cave in extreme northwest Arizona. Dietary analysis indicates that the coprolite has a human origin. This archaeological occupation is associated with the Ancestral Pueblo culture (Anasazi). This discovery supports previous hypotheses that ticks were a potential source of disease and that ectoparasites were eaten by ancient people.

Five decades of tick-man interaction in Denmark--an analysis.

The tick Ixodes ricinus (L.) is a known vector of several zoonotic diseases such as Tick Borne Encephalitis (TBE), Lyme borreliosis and ehrlichiosis. The interaction between humans and ticks are at the very core of our understanding of the epidemiology of tick borne zoonoses, but only few experimental studies have been performed. Hence our understanding of the epidemiology of tick-borne disease has to rest on the assumption that the potential tick activity, which is reflected in tick samples from the vegetation or samples from animals, corresponds with tick-human interaction. Observations which may reflect the long term tick-human contact are available in Denmark. These observations are records of requests for information on I. ricinus forwarded to the Danish Pest Infestation Laboratory (DPIL). This article was based on the assumption that the request could be seen as a measure of tick-human interaction reflecting the tick densities in relative terms. The perceived tick densities given by the number of requests on I. ricinus divided by the total number of requests to DPIL was fairly stable from 1965 to 1985, while it doubled during the late 1980's reaching a higher level in the beginning of the 1990's. The perceived density was well explained by the variation in temperature, solar radiation (monthly measurement) and deer abundance (yearly assessments). The measure of deviation, i.e. the ratio between observed requests + 1 and modelled requests + 1, for the individual years varied between 0.91 and 1.20, with considerable within-year variation. A gradual change in periodicity of the residual might suggest gradually changing tick population dynamics. In conclusion, the perceived tick densities appear to be consistent with the current knowledge of tick ecology and tick-transmitted diseases.

[History of the geographic ranges and migration routes of ticks in the genus Dermacentor Koch, 1844 (Ixodidae)]. / K istorii arealov i putei rasseleniia kleshchei roda Dermacentor Koch, 1844 (Ixodidae).

The mutually checking parasitological and zoogeographic criteria for the issue in question made it possible to express the viewpoint and present supporting data on the origin and spread of Dermacentor ticks. Their origin was dated back to Oligocene (38 mln years ago). Having appeared in Angar Mainland, the ticks spread by land in Europe, North America (Miocene, 25 mln years ago) and Africa (Pliocene, 5 mln years ago). The list of species according to zoogeographic regions is given.