Inspection for Trichinella in the EU - food safety or export concerns

The former 15 EU countries have been spending an estimated 570 million Euro yearly to inspect for Trichinella in pigs primarily raised on industrialized farms with negligible little risk of acquiring the parasite; human trichinellosis in the EU is generally caused by game meat, imported horse meat, or meat from local pigs raised outdoors

Gastrointestinal Parasites of Two Populations of Arctic Foxes (<em>Vulpes lagopus</em>) from Northeast Greenland

Parasitological examination of 275 faecal samples from Arctic foxes (Vulpes lagopus) collected at Zackenberg Valley and Karupelv Valley in north-east Greenland from 2006 to 2008 was conducted using sieving and microscopy. Overall, 125 (45.5%) samples contained parasite eggs of Taenia crassiceps, Taenia serialis, Toxascaris leonina, Eucoleus boehmi, Physalopteridae and Ancylostomatidae, and Strongyloides-like larvae. As long-term ecological studies are conducted at both sampling locations, the present findings constitute a baseline data set for further parasitological monitoring

Source attribution of human echinococcosis: A systematic review and meta-analysis

Author summary Echinococcus granulosusandE.multilocularisare zoonotic parasites that cause human cystic (CE) and alveolar (AE) echinococcosis, respectively, in humans: both diseases resulting in a substantial burden of disease. They are transmitted to humans via wild or domestic caniid definitive hosts. This study aimed at finding and evaluating the source attribution of echinococcosis and provides evidence that transmission by direct contact with the definitive hosts perhaps results in 26.1% and 34.4% cases of CE and AE, respectively. Indirect transmission by contaminated water may result in 29.4% and 24.8% of cases of CE and AE, respectively. There is evidence that indirect transmission through contaminated food may result in 23.5% of cases of CE globally. Contaminated food may result in 32.5% of cases of AE, but only in low incidence regions such as Europe. In areas of high human incidence such as China, the evidence for foodborne AE was not convincing. Other sources of transmission such as contact with a contaminated environment result in approximately 30.4% of CE cases and 11.1% of AE cases. Background A substantial proportion of echinococcosis transmission to humans via contamination of food has been assumed. However, the relative importance of food as a transmission vehicle has previously been estimated through expert opinion rather than empirical data. Objective To find and evaluate empirical data that could be used to estimate the source attribution of echinococcosis, in particular the proportion that is transmitted through contaminated food. Methods A systematic review was undertaken to identify reports on the risk factors for human cystic (CE) and alveolar (AE) echinococcosis. Data bases searched included PubMed, Scopus, Web of Knowledge, Cab Direct, Science Direct, Google Scholar, eLIBRARY.RU, CyberLeninka, CNKI and VIP. Search terms included Echinococc*, hydatid, epidemiology, logistic regression, risk factors, odds ratio, relative risk, risk factors. Reports, including grey literature where available, that had suitable data were selected and data were extracted. The main pathways of transmission were hypothesised to be contact with the definitive host, contaminated water, contaminated food and contaminated environment (other than food). For each study the attributable fraction for these potential sources of infection was calculated from the data presented. A meta-analysis was then undertaken to obtain pooled estimates for the relative contribution of these transmission pathways. Results Data from 28 cross-sectional studies and 14 case-control studies were extracted. There was strong evidence for transmission by direct contact with dogs for both CE and AE. The estimated attributable fractions were 26.1% (CI 13.8%-39.6%) and 34.4% (CI 20.7% -48.2%) respectively. Transmission through contaminated water was estimated to be responsible for approximately 29.4% (CI 12.1%-51.7%) for CE and 24.8% (CI 10.6% to 42.6%) for AE. Contaminated food may be responsible for approximately 23.4% of CE cases (CI 2.1%-47.3%). Globally, there was insufficient evidence to conclude AE can be transmitted by food, although case control studies from low human incidence areas suggested that possibly 32.5% (CI 10.0%-53.2%) could be transmitted by food. There was also insufficient evidence that direct contact with foxes was a significant source of human disease. There were no suitable studies with a risk of environmental contact reported, but the residual attributable fraction thatwould likely include this pathway was approximately 30.4% for CE and 11.1% for AE. Conclusions The results support the hypothesis that dog contact and drinking contaminated water are major pathways of transmission of both CE and AE. For contaminated food, the results are less consistent, but suggest that it is an important transmission pathway and provide better evidence than expert elicitations as previously used

Bacteria-induced egg hatching differs for Trichuris muris and Trichuris suis

Eggs of the porcine whipworm Trichuris suis are currently explored in human clinical trials as a treatment of immune-mediated diseases. In this context, only the infective, embryonated eggs, constitute the Active Pharmaceutical Ingredient (API). The rodent whipworm, Trichuris muris is commonly used as a laboratory model to study Trichuris biology. The embryonated eggs (containing a fully developed larva) are biologically active and will invade the large intestinal mucosa of the host. This study aims to assess the in vitro hatching of T. muris and T. suis eggs in various bacterial cultures as a measure for their biological activity.; Eggs of T. muris and T. suis were incubated with Escherichia coli strain (BL-21) at three concentrations in a slightly modified in vitro egg hatching assay previously developed for T. muris. Additionally, E. coli strains (M15, SG13009, PMC103, JM109, TUNER, DH5alpha, TOP10) and five Gram-positive bacteria (Enterococcus caccae, Streptococcus hyointestinalis, Lactobacillus amylovorus, L. murinus, and L. reuteri) were tested as a hatching stimulus for T. muris and T. suis eggs.; Whereas T. muris eggs hatched, T. suis did not, even when exposed to different concentrations and strains of E. coli after 4 and 24-hour incubation. When incubated with Gram-positive bacteria, only T. muris eggs showed noticeable hatching after 20 h, although with high variability.; The observed difference in hatching of T. muris and T. suis eggs incubated with selected bacteria, indicate significant biological differences which may reflect specific adaptation to different host-specific gut microbiota

Genetic differentiation of populations of Greenlandic Arctic fox

Most microsatellites are very polymorphic. This makes them powerful markers for observing genetic differentiation between closely related populations. The population structure of the Greenlandic Arctic fox (Alopex lagopus) was studied genetically by analysing six polymorphic microsatellite loci of 75 foxes from four populations in different parts of Greenland. Genotypes were determined at the six loci for most of the individuals. Population differentiation was quantified in three different ways both within the total population and pairwise between all populations. The tests were Fisher's exact test, Rho estimates and Fst estimates, all of which supported a highly significant subdivision of the total population, and they showed significant differentiation in allele frequencies between all pairs of localities. It is concluded that the known long-distance migration of the Greenlandic Arctic fox has not resulted in complete genetic mixing of the populations. Fisher's exact test was also used to estimate levels of genetic differentiation between the two colour morphs: white and blue. No difference was found between allele frequencies of the two color morphs in any of the locations, and it was concluded that the white and blue morphs of the Greenlandic Arctic fox share the same habitat, at least during the mating season

Fox serum proteomics analysis suggests host-specific responses to Angiostrongylus vasorum Infection in Canids

Dogs infected with the cardiopulmonary nematode Angiostrongylus vasorum may suffer from respiratory distress and/or bleeding disorders. Descriptions of clinical signs in foxes are rare, despite high prevalence. To evaluate the impact of infection on coagulation and immune response, serum proteins from eight experimentally infected foxes before and after inoculation (day 0, 35, 84, 154) were subjected to differential proteomic analyses based on quantitative data and compared to available data from dogs. The number of proteins with differential abundance compared to the uninfected baseline increased with chronicity of infection. Bone marrow proteoglycan, chitinase 3-like protein 1 and pulmonary surfactant-associated protein B were among the most prominently increased proteins. The abundance of several proteins involved in coagulation was decreased. Enriched pathways obtained from both increased and decreased proteins included, among others, “platelet degranulation” and “haemostasis”, and indicated both activation and suppression of coagulation. Qualitative comparison to dog data suggests some parallel serum proteomic alterations. The comparison, however, also indicates that foxes have a more adequate immunopathological response to A. vasorum infection compared to dogs, facilitating persistent infections in foxes. Our findings imply that foxes may be more tolerant to A. vasorum infection, as compared to dogs, reflecting a longer evolutionary host–parasite adaptation in foxes, which constitute a key wildlife reservoir

Mitochondrial Ribosome as the Target for the Macrolide Antibiotic Clarithromycin in the Helminth Echinococcus multilocularis

The mitochondrial rRNA of the tapeworm species Echinococcus multilocularis carries an adenine at sequence position 2058 (numbering according to that for Escherichia coli) of the large-subunit rRNA (lsrRNA), while the nucleus-encoded rRNA, as determined in this study, is characterized by 2058G. This indicates a dichotomy in the drug susceptibilities of ribosomes: cytoplasmic ribosomes are predicted to be resistant to macrolide antibiotics, while mitochondrial ribosomes lack the most common chromosomal resistance determinant, lsrRNA 2058G. Upon incubation with the macrolide clarithromycin, the formation of vesicles from metacestode tissue was reduced in a dose-dependent manner. Electron microscopy revealed distinct morphological alterations both of the mitochondria and of the vesicle wall (e.g., loss of microtriches) in drug-treated vesicles. Adult worms lost their motility and displayed morphological changes (shortening and constriction of proglottids and the presence of vacuoles) upon incubation with clarithromycin. Our findings demonstrate that macrolides have distinct in vitro effects on E. multilocularis, endorsing the use of sequence-based in silico approaches for exploitation of available ribosomal drugs as anthelmintic agents

Seroprevalence of Human Toxocariasis in Denmark▿

The seroprevalence of Toxocara in the Danish population was assessed from 3,247 sera from individuals originally screened for toxoplasmosis. Of 87 enzyme-linked immunosorbent assay-positive sera, 79 were confirmed by Western blotting, yielding a crude seroprevalence of 2.4%. This indicates that the seroprevalence of toxocariasis in Denmark is low compared to those in other European countries