High prevalence rates of Toxoplasma gondii in cat-hunted small mammals - Evidence for parasite induced behavioural manipulation in the natural environment?

Toxoplasma gondii causes one of the most frequent parasitic infections in vertebrates on earth. The present study aimed to assess the occurrence of T. gondii infection in cat-hunted wild small mammals, and to determine the circulating T. gondii genotypes in cat prey. There is evidence suggesting that T. gondii may manipulate rodents' behaviour enhancing transmission to their definitive feline host by facilitating predation. Given that most studies focusing on rodent behavior have been performed under laboratory conditions, we tested this hypothesis in the natural environment. We analysed 157 cat-hunted wild small mammals of six different species from Switzerland. Brain and skeletal muscle samples from each animal were tested for T. gondii DNA by PCR, and positive samples were genotyped using a multilocus sequence typing approach, including 10 genetic markers. Additionally, to evaluate exposure to cat faeces, the presence of Taenia taeniaeformis metacestodes was investigated at necropsy. The prevalence of T. gondii in cat-hunted Arvicola amphibius s.l. was 11.1% (7/63), 14.6% (7/48) in Apodemus spp., 13.6% (3/22) in Myodes glareolus, 6.7% (1/15) in Crocidura russula, and 0% in Microtus arvalis (0/8) and Sorex sp. (0/1). All completely genotyped T. gondii parasites, exhibited the ToxoDB #3 genotype, a Type II variant. We additionally analysed 48 trap-captured A. amphibius s.l., which all tested negative for T. gondii infection, contrasting with the higher prevalence in cat-hunted A. amphibius s.l. (0% vs. 11.1%; p = 0.0176). Furthermore, T. taeniaeformis was detected in both groups, indicating widespread contamination with cat faeces in the sampled areas. These results provide evidence that T. gondii infected rodents are at higher risk to be predated by cats and therewith support the behaviour manipulation hypothesis.

A predictive flight-altitude model for avoiding future conflicts between an emblematic raptor and wind energy development in the Swiss Alps.

Deployment of wind energy is proposed as a mechanism to reduce greenhouse gas emissions. Yet, wind energy and large birds, notably soaring raptors, both depend on suitable wind conditions. Conflicts in airspace use may thus arise due to the risks of collisions of birds with the blades of wind turbines. Using locations of GPS-tagged bearded vultures, a rare scavenging raptor reintroduced into the Alps, we built a spatially explicit model to predict potential areas of conflict with future wind turbine deployments in the Swiss Alps. We modelled the probability of bearded vultures flying within or below the rotor-swept zone of wind turbines as a function of wind and environmental conditions, including food supply. Seventy-four per cent of the GPS positions were collected below 200 m above ground level, i.e. where collisions could occur if wind turbines were present. Flight activity at potential risk of collision is concentrated on south-exposed mountainsides, especially in areas where ibex carcasses have a high occurrence probability, with critical areas covering vast expanses throughout the Swiss Alps. Our model provides a spatially explicit decision tool that will guide authorities and energy companies for planning the deployment of wind farms in a proactive manner to reduce risk to emblematic Alpine wildlife.

Decline in Distribution and Abundance: Urban Hedgehogs under Pressure.

Increasing urbanization and densification are two of the largest global threats to biodiversity. However, certain species thrive in urban spaces. Hedgehogs Erinaceus europaeus have been found in higher densities in green areas of settlements as compared to rural spaces. With recent studies pointing to dramatically declining hedgehog numbers in rural areas, we pose the question: how do hedgehogs fare in urban spaces, and do these spaces act as refuges? In this study, recent (2016-2018) and past (1992) hedgehog abundance and distribution were compared across the city of Zurich, Switzerland using citizen science methods, including: footprint tunnels, capture-mark recapture, and incidental sightings. Our analyses revealed consistent negative trends: Overall hedgehog distribution decreased by 17.6% ± 4.7%, whereas abundance declined by 40.6% (mean abundance 32 vs. 19 hedgehogs/km2, in past and recent time, respectively), with one study plot even showing a 91% decline in this period (78 vs. 7 hedgehogs/km2, respectively). We discuss possible causes of this rapid decline: increased urban densification, reduction of insect biomass, and pesticide use, as well as the role of increasing populations of badgers (a hedgehog predator) and parasites or diseases. Our results suggest that hedgehogs are now under increasing pressure not only in rural but also in urban areas, their former refuges.

Conquering Switzerland: the emergence of Angiostrongylus vasorum in foxes over three decades and its rapid regional increase in prevalence contrast with the stable occurrence of lungworms.

Angiostrongylus vasorum, Crenosoma vulpis and Capillaria aerophila are the most common lungworms of domestic and wild canids. We investigated the short- and long-term lungworm prevalence changes in the Swiss fox population with a focus on A. vasorum. Between 2012 and 2017, lungs and hearts of 533 foxes from north-eastern Switzerland were necropsied and blood samples tested for circulating A. vasorum antigen. Angiostrongylus vasorum prevalence increased steadily from 21.5% in 2012 to 81.8% in 2017. In contrast, C. aerophila and C. vulpis prevalences fluctuated between 41.8 and 74.7%, and 3.6 and 14.9%, respectively. Based on 3955 blood samples collected between 1986 and 2017 from three geographic areas and during four time periods, antigen seropositivity increased from 2.4 to 62.0%. In north-eastern Switzerland, seropositivity was initially low (1.9 and 1.7% in the first two time periods) but increased in the following two decades to 22.2 and 62.0%, respectively. Our findings depict the spectacular expansion of A. vasorum in the past three decades. Regionally, the prevalence in foxes increased 4-fold within 6 years in some regions. This underpins the important role of foxes as reservoir hosts, likely explaining the increasing number of cases of canine angiostrongylosis in Switzerland. Our findings are representative of central Europe and may help anticipating future developments in areas where A. vasorum is present but (still) infrequent.

A grid-cell based fecal sampling scheme reveals: land-use and altitude affect prevalence rates of Angiostrongylus vasorum and other parasites of red foxes (Vulpes vulpes).

In view of the role of foxes as a reservoir for Angiostrongylus vasorum, a nematode of the heart and lungs of dogs and foxes, its occurrence across Switzerland was investigated in foxes applying a standardized sampling scheme for fox fecal samples. In 72 study areas, which consisted of three 1-km2 grid cells, a total of 1481 samples were collected by walking transects following linear features in the terrain, and analyzed by a flotation-sieving method. The overall prevalence rate of A. vasorum in fecal samples was 8.8% (95% confidence interval, CI 7.4-10.3%), being significantly higher in the Swiss Plateau (11.4%, CI. 9.4-13.8%) compared with other bioregions, and more prevalent in areas with less than 50% of cultivated land (p = 0.043). Prevalence rates increased with decreasing altitudes being significantly higher below 400 m above sea level (20.6%, 95% CI 15.2-26.9%), while all samples collected above 900 m asl were negative. Eggs of Toxocara sp. (12.1%), Taeniidae (10.5%), Capillaria spp. (8.3%), Trichuris vulpis (5.5%), hookworms (5.3%), Toxascaris leonina (1.3%) and Strongyloides sp. (0.4%) were furthermore identified. Taeniid eggs were positively and Capillaria spp. negatively associated with the amount of cultivated land. The prevalence rates based on our fecal analyses were generally lower compared with previous studies from Switzerland which were based on fox necropsies. However, the grid cell-based sampling scheme with replicable transects for fox feces collection proved to be a suitable, non-invasive method for parasitic large-scale surveys providing information on the relative infectious pressure for the local dog population.

Mathematical modelling of Echinococcus multilocularis abundance in foxes in Zurich, Switzerland.

BACKGROUND: In Europe, the red fox (Vulpes vulpes) is the main definitive host of Echinococcus multilocularis, the aetiological agent of a severe disease in humans called alveolar echinococcosis. The distribution of this zoonotic parasite among the fox population is remarkably aggregated with few heavily infected animals harbouring much of the parasite burdens and being responsible for most of the environmental parasitic egg contamination. Important research questions explored were: (i) spatial differences in parasite infection pressure related to the level of urbanization; (ii) temporal differences in parasite infection pressure in relation to time of the year; (iii) is herd immunity or an age-dependent infection pressure responsible for the observed parasite abundance; (iv) assuming E. multilocularis infection is a clumped process, how many parasites results from a regular infection insult. METHODS: By developing and comparing different transmission models we characterised the spatio-temporal variation of the infection pressure, in terms of numbers of parasites that foxes acquired after exposure per unit time, in foxes in Zurich (Switzerland). These included the variations in infection pressure with age of fox and season and the possible regulating effect of herd immunity on parasite abundance. RESULTS: The model fitting best to the observed data supported the existence of spatial and seasonal differences in infection pressure and the absence of parasite-induced host immunity. The periodic infection pressure had different amplitudes across urbanization zones with higher peaks during autumn and winter. In addition, the model indicated the existence of variations in infection pressure among age groups in foxes from the periurban zone. CONCLUSIONS: These heterogeneities in infection exposure have strong implications for the implementation of targeted control interventions to lower the intensity of environmental contamination with parasite eggs and, ultimately, the infection risk to humans.

Microtus arvalis and Arvicola scherman: Key Players in the Echinococcus multilocularis Life Cycle.

A broad range of rodent species are described as potential intermediate hosts for Echinococcus multilocularis, a wide-spread zoonotic cestode causing alveolar echinococcosis. However, little is known about the relative contribution of these species for parasite reproduction and the maintenance of its life cycle. In a comparative study in a high endemic region in Zurich, Switzerland, we investigated prevalence rates and fertility of E. multilocularis in the most abundant vole species as well as the predation rate of foxes on these species. To ensure that the fox families had access to different vole species and that these voles were exposed to the same environmental contamination with parasite eggs, we selected eight study plots where at least two rodent species co-occurred. The parasite prevalence in Microtus arvalis [11.0%, confidence intervals (CI) 8.9-13.4] was significantly higher than in Arvicola scherman (5.3%, 3.9-7.1) and Myodes glareolus (3.9%, 2.0-6.7). None of the, only 29 individuals of, Microtus agrestis was infected (0%, 0.0-9.8) and the species was excluded for further analyses. Logistic regression models for the prevalences revealed significant differences between nearby study plots and higher infection rates for females, heavier individuals, and individuals trapped during spring, when the prevalence in M. arvalis peaked up to 65% (CI 50-79) in one plot. Furthermore, we detected significantly higher percentages of fertile infections in M. arvalis and M. glareolus than in A. scherman (OR 11.2 and 6.4, respectively) and a significantly higher protoscolex number in M. glareolus (median 100,000) than in M. arvalis (13,500) and A. scherman (4,290). The most abundant fox prey remains were of the genera Microtus (12.3%, CI 8.4-17.2) and Arvicola (11.5%, 7.7-16.3), whereas Myodes was never recorded as prey (0.0-1.3%). We conclude that M. arvalis and to a lesser extent A. scherman can be regarded as key intermediate hosts in Western and Central European high-endemic regions whereas M. glareolus and M. agrestis play a marginal role. We, therefore, postulate that distribution models of these species could contribute to predict parasite occurrence on a more detailed spatial scale than models of the distribution of foxes which have a very broad and uniform distribution.

Human-wildlife interactions and zoonotic transmission of Echinococcus multilocularis.

The life cycle of the zoonotic cestode Echinococcus multilocularis depends on canids (mainly red foxes) as definitive hosts and on their specific predation on rodent species (intermediate hosts). Host densities and predation rates are key drivers for infection with parasite eggs. We demonstrate that they strongly depend on multi-faceted human-wildlife interactions: vaccination against rabies, elimination of top predators, and changing attitude towards wildlife (feeding) contribute to high fox densities. The absence of large canids, low hunting pressure, and positive attitudes towards foxes modify their anti-predator response ('landscape of fear'), promoting their tameness, which in turn facilitates the colonization of residential areas and modifies parasite transmission. Such human factors should be considered in the assessment of any intervention and prevention strategy.

Stability of the southern European border of Echinococcus multilocularis in the Alps: evidence that Microtus arvalis is a limiting factor.

SUMMARY The known range of the zoonotic fox tapeworm Echinococcus multilocularis has expanded since the 1990s, and today this parasite is recorded in higher abundances throughout large parts of Europe. This phenomenon is mostly attributed to the increasing European fox populations and their invasion of urban habitats. However, these factors alone are insufficient to explain the heterogeneous distribution of the parasite in Europe. Here, we analysed the spatial interrelationship of E. multilocularis with the known distribution of seven vole species in Ticino, southern Switzerland. Among 404 necropsied foxes (1990-2006) and 79 fox faecal samples (2010-2012), E. multilocularis was consistently found in the north of the investigated area. No expansion of this endemic focus was recorded during the 22 years of the study period. This stable endemic focus is coincident with the known distribution of the vole species Microtus arvalis but not, or only partly, with the distribution of the other autochthonous vole species. Our results give evidence that this vole species plays a crucial role in the maintenance of the parasite's life cycle and that its absence could be a limiting factor for the spread of E. multilocularis in this region.

Dynamics of the force of infection: insights from Echinococcus multilocularis infection in foxes.

Characterizing the force of infection (FOI) is an essential part of planning cost effective control strategies for zoonotic diseases. Echinococcus multilocularis is the causative agent of alveolar echinococcosis in humans, a serious disease with a high fatality rate and an increasing global spread. Red foxes are high prevalence hosts of E. multilocularis. Through a mathematical modelling approach, using field data collected from in and around the city of Zurich, Switzerland, we find compelling evidence that the FOI is periodic with highly variable amplitude, and, while this amplitude is similar across habitat types, the mean FOI differs markedly between urban and periurban habitats suggesting a considerable risk differential. The FOI, during an annual cycle, ranges from (0.1,0.8) insults (95% CI) in urban habitat in the summer to (9.4, 9.7) (95% CI) in periurban (rural) habitat in winter. Such large temporal and spatial variations in FOI suggest that control strategies are optimal when tailored to local FOI dynamics.

Uneven large-scale movement patterns in wild and reintroduced pre-adult bearded vultures: conservation implications.

After the quasi-extinction of much of the European vertebrate megafauna during the last few centuries, many reintroduction projects seek to restore decimated populations. However, the future of numerous species depends on the management scenarios of metapopulations where the flow of individuals can be critical to ensure their viability. This is the case of the bearded vulture Gypaetus barbatus, an Old World, large body-sized and long-lived scavenger living in mountain ranges. Although persecution in Western Europe restrained it to the Pyrenees, the species is nowadays present in other mountains thanks to reintroduction projects. We examined the movement patterns of pre-adult non-breeding individuals born in the wild population of the Pyrenees (n = 9) and in the reintroduced populations of the Alps (n = 24) and Andalusia (n = 13). Most birds were equipped with GPS-GSM radio transmitters, which allowed accurate determination of individual dispersal patterns. Two estimators were considered: i) step length (i.e., the distance travelled per day by each individual, calculated considering only successive days); and ii) total dispersal distance (i.e., the distance travelled between each mean daily location and the point of release). Both dispersal estimators showed a positive relationship with age but were also highly dependent on the source population, birds in Andalusia and Alps moving farther than in Pyrenees. Future research should confirm if differences in dispersal distances are the rule, in which case the dynamics of future populations would be strongly influenced. In summary, our findings highlight that inter-population differences can affect the flow of individuals among patches (a key aspect to ensure the viability of the European metapopulation of the endangered bearded vulture), and thus should be taken into account when planning reintroduction programs. This result also raises questions about whether similar scenarios may occur in other restoration projects of European megafauna.

Control of Echinococcus multilocularis: strategies, feasibility and cost-benefit analyses.

Echinococcus multilocularis, the zoonotic agent of human alveolar echinococcosis, has considerably extended its range and became more prevalent in many parts of the endemic areas. Accordingly, there is an increasing demand for measures to prevent human infections. Rising public awareness of this zoonosis and individual protective actions should be part of every prevention program. Considering the high reproduction of E. multilocularis in domestic dogs which live in close contact to humans, a monthly deworming scheme for domestic dogs with access to rodents is likely to be of high importance. This holds true if only low prevalences in domestic dogs are recorded, as high densities of these pets can easily outweigh low infections rates. Thus, in central Europe their estimated contribution to environmental contamination with E. multilocularis eggs ranges between 4% and 19%. The estimated contribution of domestic cats is insignificant (<0.3%) due to low parasite reproduction in this species. Control of the parasite by reducing its main wildlife hosts (foxes, vole species) is barely achievable on a larger scale and is generally not well accepted due to ecological considerations and animal welfare concerns. In general, the frequency of the parasite sharply decreases when anthelmintic baits are regularly distributed to foxes. However, eradication of the parasite is unlikely and long-term baiting campaigns are actually the most effective tool to significantly lower the infection pressure with parasite eggs. Regarding the long latency of 5-15 years of alveolar echinococcosis, however, such measures can only be cost effective if they are pursued for several decades and concentrate on restricted areas which are most relevant for the transmission of alveolar echinococcosis such as highly endemic areas in densely populated zones. Thus, the implementation of this approach strongly depends on factors such as public attitude, available financial resources and priority setting of political decision-makers.

Spatio-temporal occurrence of Culicoides biting midges in the climatic regions of Switzerland, along with large scale species identification by MALDI-TOF mass spectrometry.

BACKGROUND: Culicoides biting midges are incriminated as biological vectors of a number of viruses, e.g. bluetongue virus. In order to define vector-free periods/areas and to assess the vectorial role of the various Culicoides species, a comprehensive knowledge on their spatio-temporal occurrence is required. METHODS: Biting midges were monitored on farm sites with livestock in the defined climatic regions, including high altitudes, of Switzerland by overnight trapping at 12 locations once a week over three years using UV-light traps. Based on morphological features, they were separated into three groups (i.e. Obsoletus, Pulicaris, other Culicoides spp.), and identification to the species level was achieved by protein profiling using MALDI-TOF mass spectrometry. RESULTS: Around 550,000 biting midges in total were collected, revealing a dominance (82 to 99%) of the Obsoletus group species up to an altitude of 1,200 m and of the Pulicaris group species above 1,500 m (85% at the highest trapping site at 2,130 m). The maximum number of midges collected in a summer night (756 to 19,682) as well as the total number of midges caught over three years (from 6,933 to 149,439) varied highly among the sites, whereas the annual variation in total midge abundance at the locations was statistically insignificant. MALDI-TOF MS of 100 randomly selected individual biting midges per trapping site yielded high quality spectra for 1,187 of the 1,200 (98.9%) specimens of which 1,173 could be assigned to one of the 15 Culicoides species for which biomarker mass sets are available in the reference database. CONCLUSIONS: There are no biting midge-free zones in all of the agriculturally utilized areas (including alpine summer pastures) of Switzerland. Annual variations of midge numbers at the sampled locations were low, indicating that monitoring of midges should preferably be done by investigating a large number of sites for one season instead of few locations for extended periods of time. High throughput species identification of midges by MALDI-TOF MS is feasible, and this technique adds to other recently developed methods for the identification of midges (PCRs in various formats, interactive identification keys), facilitating epidemiological and biological in-depth studies of these important insects.

Age, season and spatio-temporal factors affecting the prevalence of Echinococcus multilocularis and Taenia taeniaeformis in Arvicola terrestris.

BACKGROUND: Taenia taeniaeformis and the related zoonotic cestode Echinococcus multilocularis both infect the water vole Arvicola terrestris. We investigated the effect of age, spatio-temporal and season-related factors on the prevalence of these parasites in their shared intermediate host. The absolute age of the voles was calculated based on their eye lens weights, and we included the mean day temperature and mean precipitation experienced by each individual as independent factors. RESULTS: Overall prevalences of E. multilocularis and T. taeniaeformis were 15.1% and 23.4%, respectively, in 856 A. terrestris trapped in the canton Zürich, Switzerland. Prevalences were lower in young (≤ 3 months: E. multilocularis 7.6%, T. taeniaeformis 17.9%) than in older animals (>7 months: 32.6% and 34.8%). Only 12 of 129 E. multilocularis-infected voles harboured protoscoleces. Similar proportions of animals with several strobilocerci were found in T. taeniaeformis infected voles of <5 months and ≥5 months of age (12.8% and 11.9%). Multivariate analyses revealed strong spatio-temporal variations in prevalences of E. multilocularis. In one trapping area, prevalences varied on an exceptional high level of 40.6-78.5% during the whole study period. Low temperatures significantly correlated with the infection rate whereas precipitation was of lower importance. Significant spatial variations in prevalences were also identified for Taenia taeniaeformis. Although the trapping period and the meteorological factors temperature and precipitation were included in the best models for explaining the infection risk, their effects were not significant for this parasite. CONCLUSIONS: Our results demonstrate that, besides temporal and spatial factors, low temperatures contribute to the risk of infection with E. multilocularis. This suggests that the enhanced survival of E. multilocularis eggs under cold weather conditions determines the level of infection pressure on the intermediate hosts and possibly also the infection risk for human alveolar echincoccosis (AE). Therefore, interventions against the zoonotic cestode E. multilocularis by deworming foxes may be most efficient if conducted just before and during winter.

Molecular Investigations of Rickettsia helvetica infection in dogs, foxes, humans, and Ixodes ticks.

Rickettsia helvetica, a tick-borne member of the spotted-fever-group rickettsiae, is a suspected pathogen in humans; however, its role in animals is unknown. The aims of this study were to establish a R. helvetica-specific real-time TaqMan PCR assay and apply it to the analysis of tick vectors (to determine potential exposure risk) and blood samples from Canidae and humans (to determine prevalence of infection). The newly designed 23S rRNA gene assay for R. helvetica was more sensitive than a published citrate synthase gene (gltA) assay for several rickettsiae. Blood samples from 884 dogs, 58 foxes, and 214 human patients and 2,073 ticks (Ixodes spp.) collected from either vegetation or animals were analyzed. Although the maximal likelihood estimate of prevalence was 12% in unfed ticks and 36% in ticks collected from animals, none of the 1,156 blood samples tested PCR positive. Ticks from cats were more frequently PCR positive than ticks from dogs. Sequencing of the 23S rRNA and/or the gltA gene of 17 tick pools confirmed the presence of R. helvetica. Additionally, Rickettsia monacensis, which has not been previously found in Switzerland, was identified. In conclusion, R. helvetica was frequently detected in the tick population but not in blood samples. Nevertheless, due to the broad host range of Ixodes ticks and the high rate of infestation with this agent (i.e., R. helvetica was 13 times more frequent in unfed ticks than the tick-borne encephalitis virus), many mammals may be exposed to R. helvetica. The PCR assay described here represents an important tool for studying this topic.

Control strategy for Echinococcus multilocularis.

Echinococcus multilocularis, the causative agent of zoonotic alveolar echinococcosis, can be controlled effectively by the experimental delivery of anthelminthic baits for urban foxes. Monthly baiting over a 45-month period was effective for long-lasting control. Trimonthly baiting intervals were far less effective and did not prevent parasite recovery.

Survey of public knowledge about Echinococcus multilocularis in four European countries: need for proactive information.

BACKGROUND: Public information about prevention of zoonoses should be based on the perceived problem by the public and should be adapted to regional circumstances. Growing fox populations have led to increasing concern about human alveolar echinococcosis, which is caused by the fox tapeworm Echinococcus multilocularis. In order to plan information campaigns, public knowledge about this zoonotic tapeworm was assessed. METHODS: By means of representative telephone interviews (N = 2041), a survey of public knowledge about the risk and the prevention of alveolar echinococcosis was carried out in the Czech Republic, France, Germany and Switzerland in 2004. RESULTS: For all five questions, significant country-specific differences were found. Fewer people had heard of E. multilocularis in the Czech Republic (14%) and France (18%) compared to Germany (63%) and Switzerland (70%). The same effect has been observed when only high endemic regions were considered (Czech Republic: 20%, France: 17%, Germany: 77%, Switzerland: 61%). In France 17% of people who knew the parasite felt themselves reasonably informed. In the other countries, the majority felt themselves reasonably informed (54-60%). The percentage that perceived E. multilocularis as a high risk ranged from 12% (Switzerland) to 43% (France). In some countries promising measures as deworming dogs (Czech Republic, Switzerland) were not recognized as prevention options. CONCLUSION: Our results and the actual epidemiological circumstances of AE call for proactive information programs. This communication should enable the public to achieve realistic risk perception, give clear information on how people can minimize their infection risk, and prevent exaggerated reactions and anxiety.

Real-time PCR investigation of potential vectors, reservoirs, and shedding patterns of feline hemotropic mycoplasmas.

Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, "Candidatus Mycoplasma haemominutum," and "Candidatus Mycoplasma turicensis." The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods and from rodent blood or tissue samples from Switzerland and from salivary and fecal swabs from two experimentally infected and six naturally infected cats. All samples were analyzed with real-time PCR, and some positive samples were confirmed by sequencing. Feline hemotropic mycoplasmas were detected in cat fleas and in a few Ixodes sp. and Rhipicephalus sp. ticks collected from animals but not in ticks collected from vegetation or from rodent samples, although the latter were frequently Mycoplasma coccoides PCR positive. When shedding patterns of feline hemotropic mycoplasmas were investigated, "Ca. Mycoplasma turicensis" DNA was detected in saliva and feces at the early but not at the late phase of infection. M. haemofelis and "Ca. Mycoplasma haemominutum" DNA was not amplified from saliva and feces of naturally infected cats, despite high hemotropic mycoplasma blood loads. Our results suggest that besides an ostensibly indirect transmission by fleas, direct transmission through saliva and feces at the early phase of infection could play a role in the epizootiology of feline hemotropic mycoplasmas. Neither the investigated tick nor the rodent population seems to represent a major reservoir for feline hemotropic mycoplasmas in Switzerland.

Influence of urbanization on the epidemiology of intestinal helminths of the red fox (Vulpes vulpes) in Geneva, Switzerland.

Dixenous helminths that depend on rodent intermediate hosts are supposed to be negatively affected by urbanization due to lower supply of rodents in urbanized environments. Prevalence rates of dixenous, non-strictly monoxenous, and monoxenous helminths in 228 red foxes (Vulpes vulpes) along a gradient of increasing urbanization were assessed by morphological parasite identification in the city of Geneva, Switzerland. Multivariate analyses for the five most prevalent helminth species or genera revealed a significant decrease of prevalence rates for the dixenous helminths Echinococcus multilocularis and Taenia spp. from the rural (52.1 and 54.3%, respectively) to the urban area (30.0 and 20.0%, respectively), but not for the monoxenous nematode Uncinaria stenocephala (overall prevalence of 78.2%) and the non-strictly monoxenous nematode Toxocara canis (overall prevalence of 44.3%). The lower prevalence of Toxascaris leonina in the urban area (8.0%) compared to the rural area (59.6%) raises the question of whether rodent paratenic hosts play a major role for the population dynamics of this species.

Wilderness in the city: the urbanization of Echinococcus multilocularis.

A distinct increase in fox populations, particularly in urban areas, has been observed in Europe. This is of particular concern in endemic regions of the small fox tapeworm Echinococcus multilocularis, the aetiological agent of human alveolar echinococcosis. Novel tools have facilitated the investigation of the ecology of urban foxes and have demonstrated the urban wildlife cycle of E. multilocularis. Such studies are essential for estimating the risk of transmission to humans and to determine the basics for the development of control strategies.