Echinococcus Multilocularis In Red Foxes Research Articles

4D-Dynamic Representation of DNA/RNA Sequences: Studies on Genetic Diversity of Echinococcus multilocularis in Red Foxes in Poland.

The 4D-Dynamic Representation of DNA/RNA Sequences, an alignment-free bioinformatics method recently developed by us, has been used to study the genetic diversity of Echinococcus multilocularis in red foxes in Poland. Sequences of three mitochondrial genes, i.e., NADH dehydrogenase subunit 2 (nad2), cytochrome b (cob), and cytochrome c oxidase subunit 1 (cox1), are analyzed. The sequences are represented by sets of material points in a 4D space, i.e., 4D-dynamic graphs. As a visualization of the sequences, projections of the graphs into 3D space are shown. The differences between 3D graphs corresponding to European, Asian, and American haplotypes are small. Numerical characteristics (sequence descriptors) applied in the studies can recognize the differences. The concept of creating descriptors of 4D-dynamic graphs has been borrowed from classical dynamics; these are coordinates of the centers or mass and moments of inertia of 4D-dynamic graphs. Based on these descriptors, classification maps are constructed. The concentrations of points in the maps indicate one Polish haplotype (EmPL9) of Asian origin.

Echinococcus multilocularis in red foxes in North Belgium: Prevalence and trends in distribution.

A cross-sectional systematic sampling was carried out during three consecutive winters from 2012 to 2015, to update the knowledge on the fox tapeworm (Echinococcus multilocularis) distribution in the red fox (Vulpes vulpes) in Flanders. Earlier studies reported the low endemicity status of this tapeworm in the northern region of Belgium, in contrast to the south of the country and neighbouring countries. Using a modified Segmental Sedimentation and Counting Technique, followed by PCR-RFLP and sequencing, 923 foxes' intestines were examined for the presence of E. multilocularis. Based on microscopic examination, 38 out of 923 foxes were suspected to be infected with either E. multilocularis or Amoebotaenia spp., of which 19 were molecularly confirmed to be E. multilocularis, 18 were found positive for Amoebotaenia spp. and one was negative. The overall prevalence for E. multilocularis of 2.1% confirms the low endemicity of the fox tapeworm in Flanders. However, in one area in the most eastern part of Flanders (Voeren), neighbouring the Netherlands and Wallonia, a prevalence of 57% (12/21) was observed. Continuous monitoring of the fox tapeworm remains needed to assess spatio-temporal trends in distribution and to assess the risk of this zoonotic infection in Europe. The challenging differential diagnosis of E. multilocularis and Amoebotaenia spp. based on microscopic examination calls for attention.

Genetic diversity of Echinococcus multilocularis in red foxes from two Scandinavian countries: Denmark and Sweden

Echinococcus multilocularis is an endemic parasite of red foxes in several European countries. This parasite has been present for decades in central Europe i.e. Switzerland, Eastern France, Southern Germany and Austria, which constitute the core endemic area of Europe. In the Scandinavian countries Sweden and Denmark, several recent findings were made in foxes. To better understand the dynamics and geographic spread of E. multilocularis in Europe, genetic studies have been undertaken using the DNA microsatellite marker EmsB. In Europe, the parasite spread in hitherto non-endemic areas was suspected to take place after founder events, in which the core endemic area presents a wider genetic diversity in comparison to newly endemic areas. However, identical parasite profiles can be shared between them, highlighting the parasite spreading in a mainland-island system. In this study, Swedish (27 adult worms from seven red foxes) and Danish (38 adult worms from nine red foxes) isolates were examined using fragment size analyses of the tandemly repeated microsatellite EmsB in order to compare the genetic profiles of the Scandinavian worms with a reference collection of European worm isolates from seven countries. Six EmsB profiles were detected in the Scandinavian panel. Three profiles were described in Denmark and four in Sweden. Only one of these profiles was detected in both countries. All profiles identified in the present study have previously been found in other European countries, suggesting an epidemiological link. Due to the relatively low number of Scandinavian E. multilocularis isolates analysed so far, firm conclusions cannot be made regarding the true genetic diversity. Nevertheless, the low genetic variation detected in Sweden and Denmark in this study is similar to the values obtained from peripheral areas of the main European endemic focus, which were more recently colonized by E. multilocularis; and continuous surveillance of this parasite is warranted to provide further insight into its epidemiology in Scandinavia.

Investigation of Echinococcus multilocularis in Environmental Definitive Host Feces in the Asian and the European Parts of Turkey.

A study was carried out to investigate the presence of Echinococcus multilocularis in red foxes (Vulpes vulpes) in two regions of Turkey—central Anatolia (in Asia Minor) and Thrace (in the European part of Turkey). A total of 405 putative fox feces were collected from central Anatolia (186 specimens in 59 locations) and from Thrace (219 specimens in 114 locations). All samples were examined by the flotation and sieving method for taeniid eggs, and positive and putative samples were further analyzed by multiplex PCR. In seven samples from three locations in central Anatolia (5.1%) and in one (0.9%) from Thrace, E. multilocularis DNA was amplified, and this result was confirmed with another PCR specific for E. multilocularis. In addition, Echinococcus granulosus s.l. was found in two (0.5%) of the samples. Although alveolar echinococcosis (AE) is known as a serious zoonosis in Turkey, this is the first field study detecting E. multilocularis in collected fecal samples documenting the environmental contamination with eggs of this zoonotic parasite.

Genetic diversity of Echinococcus multilocularis in red foxes in Poland: the first report of a haplotype of probable Asian origin

The aim of the present study was to estimate the genetic diversity of the cestode Echinococcus multilocularis Leuckart, 1863 in Poland based on sequence analysis of the mitochondrial genes of worms isolated from red foxes, Vulpes vulpes (Linnaeus). Overall, 83 adults of E. multilocularis from the same number of foxes in different parts of Poland were used for analysis. Sequences of the three mitochondrial genes, cytochrome b (cob), NADH dehydrogenase subunit 2 (nad2) and cytochrome c oxidase subunit 1 (cox1), were analysed. Seventy-four individual biological samples were successfully sequenced. Combined sequence analysis of these three genes exhibited fifteen Polish haplotypes (EmPL1-EmPL15). Most isolates (n = 29; 39%) were classified to the EmPL1 haplotype, which occurred mainly in the east, north and centre of Poland. Haplotype EmPL4 (n = 14; 19%) and other haplotypes appeared predominantly in the south and west area. Fourteen haplotypes were grouped in the European clade. One Polish haplotype (EmPL9) (n = 7, 10%) was assigned to the Asian clade with haplotypes from Japan and Kazakhstan. This haplotype was found only in northeast Poland and this is the westernmost report of haplotype of E. multilocularis belonging to the Asian clade in Europe. The investigation demonstrated that populations of E. multilocularis in Poland (and probably also in eastern Europe) included not only different European haplotypes but also those of the Asian origin.

The prevalence of Echinococcus multilocularis in red foxes in Poland—current results (2009–2013)

The aim of the study was to determine the prevalence of Echinococcus multilocularis in red foxes (Vulpes vulpes) in Poland. Overall, 1,546 intestinal samples from 15 of the 16 provinces in Poland were examined by the sedimentation and counting technique (SCT). The mean prevalence of E. multilocularis in Poland was 16.5 % and was found in 14 of the 15 examined provinces. The mean intensity of infection was 2,807 tapeworms per intestine. Distinct differences in prevalence were observed between regions. In some provinces of eastern and southern Poland, the level of prevalence was 50.0 % (Warmińsko-Mazurskie), 47.2 % (Podkarpackie), 30.4 % (Podlaskie) and 28.6 % (Małopolskie), while in other provinces (west and south-west), only a few percent was found: 2.0 % (Dolnośląskie), 2.5 % (Wielkopolskie) and 0.0 % (in Opolskie). The border between areas with higher and lower prevalence seems to coincide with a north–south line running through the middle of Poland, with prevalence from 17.5 to 50.0 % in the eastern half and from 0.0 to 11.8 % in the western half. The dynamic situation observed in the prevalence of this tapeworm indicated the necessity of continuing to monitor the situation concerning E. multilocularis in red foxes in Poland.

Efficacy of anthelmintic baiting of foxes against Echinococcus multilocularis in northern Japan

Field application of anthelmintic baits against Echinococcus multilocularis in red foxes (Vulpes vulpes) was conducted on Nemuro Peninsula at the eastern edge of Hokkaido, Japan. The total study area was 412km2, of which 135km2 were used for bait distribution. Commercial baits containing 50mg praziquantel were distributed by car along roads outside towns and villages in a density of 15/km2. Additional baits were distributed around fox breeding dens. Baiting was done from November 1999 to January 2006 at an average frequency of 4.3 distribution rounds per years (in total 27 rounds). Prevalence in foxes collected in the baiting and non-baiting areas were determined by necropsy. Base prevalence (before baiting) was 49.4% (CI95%: 43.7–55.0) in the baiting area and 70.5% (CI95%: 60.2–79.2) in the non-baiting area. During the first and second half of the baiting period, the prevalence in the baited area changed to 26.2% (CI95%: 14.4–42.3) and later to 15.8% (CI95%: 7.9–28.4), but remained at a high level in the neighboring non-baited area with 60.4% (CI95%: 45.3–73.9) and 65.0% (CI95%: 40.9–83.7). Our data show, that significant prevalence reduction (but not elimination) of E. multilocularis in foxes can be achieved by this method under epidemiological conditions, which are fundamentally different from those in Europe where most previous studies have been done.

Detection of a high-endemic focus of Echinococcus multilocularis in red foxes in southern Denmark, January 2013

The Danish surveillance programme for Echinococcus multilocularis was initiated in September 2011, and so far 679 wild carnivores have been examined. In April 2012, one infected fox was detected in Højer near the Danish-German border, and in January 2013 three additional foxes from the same area were found infected. Local prevalence in the area was 31% (four of 13 foxes) which is a new epidemiological situation calling for reevaluation of the national risk management.

Technical specifications for monitoring Community trends in zoonotic agents in foodstuffs and animal populations

Technical specifications are proposed for the monitoring of temporal trends in zoonotic agents in animal and food populations at Community or Member State group level in the framework of Directive 2003/99/EC. Two types of trend monitoring are identified: trend watching, which covers general observations of harmonised or non-harmonised data for possible trends, and trend analyses which means statistical analyses of harmonised data for the detection of trends over time. Trend watching can be regarded as the first and preliminary step in trend monitoring. The specifications identify a set of criteria for the selection of the zoonotic agent/animal or food category combinations where trend analyses would be justified. Based on data available from 2004 to 2007, the following combinations are suggested for trend analyses: Salmonella in fresh broiler and pig meat, flocks of laying hens and broilers, slaughter and breeding pigs as well as fattening turkeys; Campylobacter in fresh broiler meat; Listeria monocytogenes in smoked fish; Mycobacterium bovis in bovine herds; Brucella in bovine and caprine/ovine herds in co-financed non-officially free Member States; verotoxigenic Escherichia coli O157 in cattle; and Echinococcus multilocularis in red foxes. This list is proposed to be revised on a regular basis taking into account most recent knowledge. Suggestions for minimum sample sizes and number of time points needed for identifying trends are provided. Weighting of the national results should be applied at Community level in order to account for the different sizes of national populations. Biological relevance of trends depends on several factors such as the prevalence of the agent in the population, and the severity of the disease in question, as well as on the impact of the trend on the exposure to humans. Statistical significance of a trend observed in data is therefore only one of the factors impacting on the biological relevance of an observed trend.

Emergence of Echinococcus multilocularis among Red Foxes in northern Germany, 1991–2005

The parasite Echinococcus multilocularis is currently of great concern in Europe because of its spreading behavior, which has public health implications. This study investigates the spatiotemporal distribution of Echinococcus multilocularis in Red Foxes. The infection status of 8459 foxes was sampled from 43 regions in the north German province of Lower Saxony over three investigation periods 1991–1994, 1994–1997 and 2003–2005. Linear empirical Bayesian smoothing within the binomial model was used to produce smoothed choropleth maps. Geostatistical kriging was applied to generate prevalence risk maps. Further geostatistical modeling of the prevalence difference between study periods facilitated spatiotemporal trend investigations. The spatial scan statistic was used for cluster detection analysis. The average prevalence risk for Lower Saxony increased from about 12 to 20% during 1991–2005. Specifically the increases from first to second and to third study periods were estimated by 3.3% (CI 95%: 0.6%–5.9%) and 8.5% (CI 95%: 5.2%–11.8%), respectively. Infections in foxes were clustering and a location stable disease cluster was detected in the south of the province. This study is the first showing evidence for steady emergence of Echinococcus multilocularis in Red Foxes. First cases of human Alveolar Echinococcosis were recorded recently.

Occurence of Echinococcus multilocularis in red foxes (Vulpes vulpes) in southern Poland

Abstract The prevalence of Echinococcus multilocularis in 214 red foxes (Vulpes vulpes) in the southern part of Poland (Małopolskie voivodship) was evaluated post mortem in 2005. Infected foxes were found in 8 districts within 17 examined, with the prevalence from 10.0 % to 63.9 % (a mean 20.1 % in the whole study area). The highest prevalence (41.2 % and 63.9 %) was revealed in two districts, in the south and the east of the province, respectively. The high prevalence of E. multilocularis in red foxes in the region previously recognised as that of low parasite endemicity provides evidence for the need of regular screening of the current epidemiological situation in foxes as well as the monitoring of humans from risk groups for early recognition of possible AE cases.

Spatial spreading of Echinococcus multilocularis in Red foxes ( Vulpes vulpes) across nation borders in Western Europe

The occurrence of the fox tapeworm Echinococcus multilocularis in Red foxes was studied in Belgium and a neighbouring region in The Netherlands. A total number of 1202 foxes were analysed (1018 in Belgium and 184 in The Netherlands) of which 179 were infected with E. multilocularis (164 in Belgium and 15 in The Netherlands). Further, the spatial distribution of infection among sampled foxes was analysed with an ellipsoidal gradient, demonstrating a decreasing prevalence in northwestern direction. Using this gradient, we showed that the spatial patterns of infection in Belgium and the neighbouring region in The Netherlands correspond, indicating a continuous distribution of E. multilocularis across the nation borders. Part of the Belgian data allowed investigating temporal changes in the spatial distribution of E. multilocularis. This revealed a northwestern spread of E. multilocularis.

Occurrence of Echinococcus multilocularis in red foxes from the Carpathian regions of Slovakia and Poland

AbstractThe extensive distribution of Echinococcus multilocularis cestode from endemic alpine areas to the parts of Central Europe has been recorded in recent years. The first confirmed finding of E. multilocularis in Slovakia was recorded in 1999 in the area adjacent to the Polish border. At present, this serious zoonosis occurs almost across the whole territory of Slovakia. The occurrence of these tapeworms in red foxes (Vulpes vulpes) at the border regions of Slovakia and Poland has been monitored. In these districts, out of 152 faecal samples examined, 36.2% were positive for the coproantigen-ELISA. With the sedimentation and counting technique the prevalence of E. multilocularis in red foxes was up to 38.8%. The examination of foxes from neighbouring districts revealed worm burden ranging from 1–15,000 specimens, but the majority of animals harboured medium number of tapeworms. In the Small Carpathian and Sub-Carpathian regions of Poland, out of 65 samples examined, 13.8% were coproantigen positive. Using the small intestine scraping method only 6.1% prevalence of E. multilocularis in red foxes was determined, mostly with a high worm burdens over 1,000 specimens. The results suggest possible transborder transmission of E. multilocularis, the causative agent of serious alveolar echinococcosis.

Echinococcus multilocularis in red foxes ( Vulpes vulpes) of the Italian Alpine region: is there a focus of autochthonous transmission?

Alveolar echinococcosis, caused by the metacestode of Echinococcus multilocularis, is a zoonosis with a wider distribution area than described in the past. Fox populations living in the Alpine regions of Italy had been considered free from this parasite until 2002, when two infected foxes ( Vulpes vulpes) were detected in the Bolzano province (Trentino Alto Adige region) near the Austrian border. The aim of this work was to evaluate the prevalence of infection in red fox populations from five Italian regions. A modified nested PCR analysis was used to detect E. multilocularis DNA in faecal samples. Amplicons were confirmed by sequencing. Of 500 faecal samples from foxes shot in Valle d'Aosta ( n=57), Liguria ( n=44), Lombardy ( n=102), Veneto ( n=56), and Trentino Alto Adige ( n=241) regions, 24 animals, all from the Trentino Alto Adige region, were found positive. Twenty-two positive animals originated from the Bolzano province and two positive animals from the Trento province. Several localities of the Bolzano province, in which positive foxes were detected, are the same as those where alveolar echinococcosis had been described in humans in the second half of the 19th century, suggesting an old endemicity for the investigated area, which is adjacent to endemic areas of Austria. Therefore, the question arises if we are observing an increase and expansion of foci, or if the new records are due to the more sensitive and specific methods used to detect the worm DNA.

Choropleth mapping of regional count data of Echinococcus multilocularis among red foxes in Lower Saxony, Germany

In this paper, choropleth maps display the geographical distribution of Echinococcus multilocularis in red foxes in Lower Saxony. Areas of high prevalence of the infection in foxes and with high fox population density pose high risk for the human population for alveolar echinococcosis. Spatial statistical methods were used to analyse regional count data obtained from 5365 hunted or found-dead foxes. Spatial smoothing (of raw estimates of regional prevalences based on count data before mapping) was used because raw estimates can give an erratic impression of the spatial pattern of the infection. For smoothing, empirical Bayesian methods are used as an explorative spatial epidemiological tool. The resulting map showed the geographical variation of the estimated prevalences around a median at 9% and indicated the presence of spatial-trend effects. Based on this finding, conditional autoregressive spatial modelling for Freeman–Tukey transformed data was used as an inferential spatial epidemiological tool. There were significant additive linear and quadratic spatial-trend effects with elevated prevalences in the north and south and extreme values (prevalences>38%) for the south of Lower Saxony.

Evaluation of fox-chasing enclosures as sites of potential introduction and establishment of Echinococcus multilocularis.

Following detection of Echinococcus multilocularis in red foxes (Vulpes vulpes) illegally imported into South Carolina (USA) for release in fox-chasing enclosures, a survey for E. multilocularis was conducted in four enclosures in Georgia (USA) and six enclosures in South Carolina. Survey methods included examination of potential small mammal intermediate hosts (n = 390) for E. multilocularis larvae, examination of fox and coyote (Canis latrans) scats (n = 59) for taeniid eggs, and examination of one possible canine definitive hosts for adult E. multilocularis. All intermediate and definitive hosts examined were negative for E. multilocularis and taeniid eggs were not recovered from fox and coyote fecal samples. Thus, E. multilocularis may not yet be established in fox-chasing enclosures in Georgia and South Carolina. Despite the failure to demonstrate E. multilocularis in the fox-chasing enclosures surveyed, translocation of wild canids from known enzootic regions should be discouraged because E. multilocularis is known to be ecologically adaptable and because contact with potentially infected definitive hosts during translocation is a public health risk.