An updated and increased compilation of georeferenced tick locations in Germany is presented here. This data collection extends the dataset published some years ago by another 1448 new tick ...locations, 900 locations of which were digitized from literature and 548 locations are published here for the first time. This means that a total of 3492 georeferenced tick locations is now available for Germany. The tick fauna of Germany includes two species of Argasidae in the genera
Argas
and
Carios
and 19 species of Ixodidae in the genera
Dermacentor
,
Haemaphysalis
, and
Ixodes
, altogether 21 tick species. In addition, three species of Ixodidae in the genera
Hyalomma
(each spring imported by migratory birds) and
Rhipicephalus
(occasionally imported by dogs returning from abroad with their owners) are included in the tick atlas. Of these, the georeferenced locations of 23 tick species are depicted in maps. The occurrence of the one remaining tick species, the recently described
Ixodes inopinatus
, is given at the level of the federal states. The most common and widespread tick species is
Ixodes ricinus
, with records in all 16 federal states. With the exception of Hamburg,
Dermacentor reticulatus
was also found in all federal states. The occurrence of the ixodid ticks
Ixodes canisuga
,
Ixodes frontalis
,
Ixodes hexagonus
and
I. inopinatus
were documented in at least 11 federal states each. The two mentioned argasid tick species were also documented in numerous federal states, the pigeon tick
Argas reflexus
in 11 and the bat tick
Carios vespertilionis
in seven federal states. The atlas of ticks in Germany and the underlying digital dataset in the supplement can be used to improve global tick maps or to study the effects of climate change and habitat alteration on the distribution of tick species.
BACKGROUND: Georeferenced locations of ixodid ticks are required to depict the observed distribution of species. Further, they are used as input data for species distribution models also known as ...niche models. The latter were applied to describe current and future (projected) tick distributions. Beside model assumptions and selected climate parameters, the number of georeferenced tick locations available as a digital dataset is of fundamental importance for the reliability of such models. For Germany, however, no comprehensive dataset of ixodid tick species exists. The goal of this study was to put together all the available information on ixodid tick locations in Germany to produce such a digital dataset and to visualize it in a map. FINDINGS: A total of 2,044 georeferenced locations of ixodid ticks in Germany were compiled from two existing datasets (altogether 993 locations) and an extensive literature study (1,051 locations). The resulting digital dataset comprises the following tick species: Ixodes ricinus (1,855 locations), Ixodes apronophorus (1), Ixodes frontalis (1), Ixodes hexagonus (1), Ixodes trianguliceps (4), Dermacentor marginatus (77), Dermacentor reticulatus (96), Haemaphysalis concinna (8) and Hyalomma marginatum (1). The data were used to draw a tick map for Germany, showing I. ricinus occurring in the whole federal territory, while D. marginatus has been restricted to the climatically favoured region of the Rhine valley. Clustered locations of D. reticulatus were also documented in the Rhine valley as well as in Berlin and its vicinity. CONCLUSIONS: The introduced map depicts for the first time the available geographical coordinates of ixodid tick locations in Germany. The digital dataset used to draw the map is provided to the scientific community as a basis for further investigations such as species distribution modelling.
Ticks are arthropods and the most important vectors of major human diseases after mosquitoes. Due to their impact on public health, in vitro and in vivo assays have been developed to identify ...molecules with repellent activities on ticks. Repellents are useful to reduce tick bite exposure and the potential transmission of pathogens; they can be used topically or in impregnated clothing. Presently, mainly synthetic molecules are commercialized as skin repellents, e.g., N,N-diethyl-meta-toluamide (DEET), IR3535, picaridin or KBR 3023, and para-menthanediol. Permethrin is largely used for fabric impregnation. Intensive research has been conducted to identify new molecules with repellent activity and more recently, plant-derived molecules, as an alternative to synthetic molecules.
Ticks of the species Ixodes ricinus are the main vectors of Lyme Borreliosis and Tick-borne Encephalitis - two rapidly emerging diseases in Europe. Repellents provide a practical means of protection ...against tick bites and can therefore minimize the transmission of tick-borne diseases. We developed and tested seven different dodecanoic acid (DDA)-formulations for their efficacy in repelling host-seeking nymphs of I. ricinus by laboratory screening. The ultimately selected formulation was then used for comparative investigations of commercially available tick repellents in humans.
Laboratory screening tests were performed using the Moving-object (MO) bioassay. All test formulations contained 10% of the naturally occurring active substance DDA and differed only in terms of the quantitative and qualitative composition of inactive ingredients and fragrances. The test procedure used in the human bioassays is a modification of an assay described by the U.S. Environmental Protection Agency and recommended for regulatory affairs. Repellency was computed using the equation: R = 100 - NR/N x 100, where NR is the number of non-repelled ticks, and N is the respective number of control ticks. All investigations were conducted in a controlled laboratory environment offering standardized test conditions.
All test formulations strongly repelled nymphs of I. ricinus (100-81% protection) as shown by the MO-bioassay. The majority of ticks dropped off the treated surface of the heated rotating drum that served as the attractant (1 mg/cm2 repellent applied). The 10% DDA-based formulation, that produced the best results in laboratory screening, was as effective as the coconut oil-based reference product. The mean protection time of both preparations was generally similar and averaged 8 hours.Repellency investigations in humans showed that the most effective 10% DDA-based formulation (~1.67 mg/cm2 applied) strongly avoided the attachment of I. ricinus nymphs and adults for at least 6 hours. The test repellent always provided protection (83-63%) against I. ricinus nymphs equivalent to the natural coconut oil based reference product and a better protection (88-75%) against adult ticks than the synthetic Icaridin-containing reference repellent.
We found that the 10% DDA-based formulation (ContraZeck(R)) is an easily applied and very effective natural repellent against I. ricinus ticks. By reducing the human-vector contact the product minimises the risk of transmission of tick-borne diseases in humans.
A high-resolution city map showing the geographic distribution of 12 tick species (Acari: Argasidae, Ixodidae) that have been recorded from the metropolitan area of Berlin, Germany is presented. A ...total of 237 tick locations was mapped. These include ten ixodid tick species: Dermacentor reticulatus, Haemaphysalis concinna, Hyalomma rufipes, Ixodes ricinus, Ixodes canisuga, Ixodes hexagonus, Ixodes arboricola, Ixodes frontalis, Ixodes trianguliceps and Rhipicephalus sanguineus sensu lato. The two tick species Hy. rufipes and R. sanguineus s.l. are not endemic to Berlin. Hyalomma rufipes ticks are introduced in Europe with migratory birds from Africa every spring. Rhipicephalus sanguineus s.l. are introduced to Central Europe with dogs that had travelled to or were imported from countries where this tick is endemic. In Germany, they are able to develop and reproduce inside heated buildings. Occurrences of two soft tick species, the pigeon tick Argas reflexus and the short-legged bat tick Carios vespertilionis were also mapped. Other tick species that are likely to be endemic to Berlin and its environs, but for which documented findings or geographical coordinates are lacking, are mentioned. These include the long-legged bat tick I. vespertilionis and the marten tick I. rugicollis documented in Brandenburg, the federal state surrounding Berlin. It can be assumed that if appropriate field studies are carried out, these tick species will also be found in the metropolitan area of Berlin. The high-resolution mapping of all tick species found in a city (like Berlin) forms the basis for further investigations into the impact of climate change and changing land use on ticks and tick-borne diseases, precisely in those habitats where most people will live in the future.
The goal of this paper is to present up-to-date maps depicting the geographical distribution of Dermacentor species in Europe based on georeferenced sampling sites. Therefore, a dataset was compiled, ...resulting in 1286 D. marginatus (Sulzer, 1776) and 1209 D. reticulatus (Fabricius, 1794) locations. Special emphasis is given to the region of the European Alps depicting a presumable climate barrier of the mountains and to overlaps in the distribution of both species as well as on the situation in eastern European countries. For the latter newly described Dermacentor findings comprise 59 locations in Romania and 62 locations in Ukraine. The geographical distributions of both species in Europe range from Portugal to Ukraine (and continue to the east of Kazakhstan). Although it is well known that D. marginatus is adapted to a warmer and drier climate at more southern latitudes and D. reticulatus to a moderately moist climate at more northern latitudes, the distribution limits of both species were not well known. Here, the northern and southern distribution limits for both species in Europe, as determined from the georeferenced database, were specified for D. marginatus by the belt of 33-51° N latitude and for D. reticulatus by the belt of 41-57° N latitude. Thus, overlapping species distributions were found between 41° N and 51° N.
Two studies were performed to elucidate the current distribution of the tick
Dermacentor reticulatus in Germany. In the first one in 2003, a total of 365 dogs from 171 sites in the states of Berlin ...and Brandenburg was screened for ticks, and the corresponding outdoor sites that the dogs usually visited were searched for host-seeking ticks by the flagging method. A total of 1155 ticks was removed from the dogs. The majority were
Ixodes ricinus (88.5%), followed by
D. reticulatus (9.1%) and
I. hexagonus (2.4%). Altogether, 222 dogs carried
I. ricinus (60.8%), 41
D. reticulatus (11.2%) and 15
I. hexagonus (4.1%) ticks. Based on scutal index determination, the removed
I. ricinus and
D. reticulatus had been feeding on the dogs for a mean of 4.0 and 4.5 days, respectively. The dogs infested with
D. reticulatus lived at 26 different sites, all previously unknown as
Dermacentor sites. Seven of the sites could be confirmed subsequently by flagging the vegetation for ticks. In the second study, a total of 721 deer was shot at 201 different sites from a total of 160 districts all over Germany during the autumn hunting season 2004. A total of 23 deer (3.2%) originating from 14 sites was infested with
D. reticulatus. Hereby, significantly more red deer (
Cervus elaphus elaphus) than roe deer (
Capreolus capreolus) or fallow deer (
Dama dama) harboured
D. reticulatus ticks. Only two of the sites found had already been known as
D. reticulatus areas, whereas all other sites in Brandenburg, Saxony Anhalt, Hesse and Bavaria had been unknown. The results of both studies show that
D. reticulatus presently occurs at far more sites than previously known in Germany and thus most likely has expanded its range. Additionally, a total of 135
D. reticulatus removed from deer was screened for
Babesia canis and
Rickettsia sp. by PCR. A total of 31
D. reticulatus (23%) were positive for
Rickettsia. Sequencing revealed in all cases 100% identity with the strain RpA4 that was first isolated from
Rhipicephalus ticks in Russia.
Increasing resistance of head lice against neurotoxic agents and safety concerns have led to the search for treatment alternatives. Dimeticones with a physical mode of action are safe, and bear a ...reduced risk for the development of resistance.
We performed in vitro bioassays to assess pediculicidal and ovicidal activities of a new dimeticone-based product, and a randomized controlled clinical trial to assess efficacy, following 10 min application. Of 153 individuals screened, 100 participants with active head louse infestations were randomly assigned to treatment with either a dimeticone-based test product, or a 0.5% permethrin-based reference product (50 participants per group). Participants received two topical applications of either the test (10 min) or reference products (45 min) at days 0 and 7 or 8. Outcome measures included the efficacies of treatment and their safety, as well as global and local tolerability at baseline, and days 1, 7, and 10.
After 10 min exposure, all lice treated with the dimeticone test product were classified as non-viable in the in vitro assay. Ovicidal activity after treatment of eggs with the dimeticone test product was 96.8%. In the clinical trial, 96 patients completed all study visits. In the full analysis set (FAS) population, on day 1 after one application, 98% of patients were cured in the test group, as compared to 84% cured in the reference group. All participants in both groups were free of head lice on day 10, following two applications (100% cure rate). In total, 42 adverse events (AEs) in 23 patients of both treatment groups were recorded, with the majority of AEs classified as mild.
We have shown a high level of pediculicidal and ovicidal activity, and clinical efficacy and safety, of a brief application of a new dimeticone-based product. The short application time and reduced risk for the development of resistance are key drivers for improved patients' compliance.
EU Clinical Trials Register EudraCT 2016-004635-20 . Registered 14 November 2016.
Test systems for tick repellents Dautel, Hans
International journal of medical microbiology,
04/2004, Letnik:
293
Journal Article
Recenzirano
There is an interest in the development of repellents for personal protection of humans and animals against ticks. Evaluation of new substances or formulations needs adequate test procedures to show ...efficacy of the compounds. A variety of repellent assays for ticks are described in the literature. Available biotests can be grouped in three categories (i) use of live hosts, (ii) use of some kind of tick attractant associated with hosts, or (iii) no use of attractants at all. The latter are often better to standardize and are cheap, but suffer from a poor ability to filter out weak repellents. The former two are usually more predictive in terms of forecasting the efficacy of the product under practical conditions, although sometimes difficult to standardize, particularly in the field, but usually expensive and time consuming. Therefore, recent developments concentrated on laboratory assays like the Moving-object bioassay or the human volunteer test, allowing the tick to display its host-seeking behaviour as close as possible to that shown in nature, yet offering a standardized procedure.
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