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Harbour porpoises (Phocoena phocoena) are the only cetacean residents found year-round in Swedish waters and they are exposed to numerous natural and anthropogenic threats. Since the in situ monitoring of cetaceans can be difficult, invasive and often expensive, investigation of stranding patterns and examination of stranded animals can be used as a cost-effective source of data to study these elusive animals. The aim of this study was to investigate the spatiotemporal patterns of harbour porpoise stranding reports and the possible underlying causes in Swedish waters over a ten-year period (2014-2023). Additionally, the Swedish stranding network plays a key role in the collection of stranded carcasses for health and disease surveillance, and geographic coverage of the network also was analysed. When making spatial comparisons, the ten-year period was divided into two five-year blocks. Data on 854 stranded harbour porpoises were analysed from the coasts of the Skagerrak, Kattegat, and Baltic Seas. Both significant spatial and temporal patterns could be identified. Strandings peaked in July through September and hotspots occurred along most of the Swedish west coast, with the most frequent hotspots located around & Ouml;resund and especially the area around the Kullen peninsula. The spatial patterns of strandings found in this study are consistent with data on porpoise abundance, prey abundance, and gillnet fisheries' efforts. The latter is known to be one of the primary causes of porpoise mortality. Furthermore, the coverage of the Swedish stranding network increased between the two periods, likely reflecting an increased awareness of the carcass-based surveillance program, and gaps requiring network expansion efforts were identified. These results also provide baseline data to enable the continued monitoring of stranding trends, as changes may indicate changes in population distribution, size or mortality rates.

Avian influenza (AI) is an infectious viral disease of birds, including domestic poultry, which has been causing outbreaks worldwide, leading to several millions of dead wild birds and culled poultry. AI is mainly found in birds, but recently, there was an increase in reported infections in mammals, ranging from no symptoms to mass mortality events and some human cases. Epidemiologically of great concern, evidence of mammalian adaptations have been found, but the transmission routes and pathogenesis in mammals are still to be defined. Hence, it is paramount to address all facets of AI viruses epidemiology, including investigating taxa not customarily thought to be involved in the transmission and/or trafficking of AI, such as wild mammals. The scope of this report was to assess the role of mammals in AI epidemiology, virology and pathology, i.e. AI maintenance, reservoir role, immunity, role of mammals in a potential pandemic. To do so, we performed an all-encompassing review of the literature on the topic with a two-fold approach: a systematic review of the published AI cases in wild mammals and a narrative approach to provide an expert opinion on the role of mammals in AI spread. The final number of peer-reviewed papers included in the systematic literature review was 76, resulting in 120 unique infection records with AI in wild mammal species. The most represented taxa were included in the order Carnivora. The risk of infection was identified mainly as predation (or feeding) upon infected birds or contact with avian species. Evidence of mammal-to-mammal transmission in the wild is only circumstantial and yet to be confirmed. Cases of AI from the systematic review of experimental findings were discussed concerning epidemiology, pathology and virology. Knowledge gaps and potential pandemic drivers were identified. In summary, although a greater number of infections in wild mammals have been reported, there is no hard evidence for sustained mammal-to-mammal transmis

In 2020/2021, several European brown hare syndrome virus (EBHSV) outbreaks were recorded in European hares (Lepus europaeus) from Catalonia, Spain. Recombination analysis combined with phylogenetic reconstruction and estimation of genetic distances of the complete coding sequences revealed that 5 strains were recombinants. The recombination breakpoint is located within the non-structural protein 2C-like RNA helicase (nucleotide position ~ 1889). For the genomic fragment upstream of the breakpoint, a non-pathogenic EBHSV-related strain (hare calicivirus, HaCV; GII.2) was the most closely related sequence; for the rest of the genome, the most similar strains were the European brown hare syndrome virus (EBHSV) strains recovered from the same 2020/2021 outbreaks, suggesting a recent origin. While the functional impact of the atypical recombination breakpoint remains undetermined, the novel recombinant strain was detected in different European brown hare populations from Catalonia, located 20–100 km apart, and seems to have caused a fatal disease both in juvenile and adult animals, confirming its viability and ability to spread and establish infection. This is the first report of a recombination event involving HaCV and EBHSV and, despite the recombination with a non-pathogenic strain, it appears to be associated with mortality in European brown hares, which warrants close monitoring.

Five terms of reference (ToRs) were addressed at the working group. The first three terms of reference were standing ones. Under ToR A, new information on cetacean and seal population abundance, distribution, and population/stock structure, was reviewed, including information on vagrancy in cetacean and pinniped species. For cetaceans, coverage from the latest SCANS-IV survey (summer 2022) was presented as well as the results of recent regional/national surveys, particularly those in the Bay of Biscay and around the Iberian Peninsula. Updates on population estimates and distribution were provided for particular species studies, such as some coastal bottlenose dolphin populations. For seals, latest monitoring results were given for harbour, grey, and Baltic and Saimaa ringed seals. In addition, where possible, local long-term trends were illustrated for those species, based on earlier efforts by WGMME to assemble these data into a seal database. For both species’ groups, recent records of vagrant species were summarised. Under ToR B, cetacean and seal management frameworks in the North Atlantic were discussed, with an overview of the EU Maritime Spatial Planning Directive, and examples from the United Kingdom, Spain and the Faroe Islands of national management frameworks regarding marine mammals., ToR C provided an overview of new published information with regards to anthropogenic threats to marine mammal populations following on from the review by WGMME in 2015 (ICES, 2015) and subsequent updates. These were considered under the following headings: cumulative effects, fishery interactions, chemical pollution including marine debris, underwater noise, ship strikes and other physical trauma, tourism disturbance, climate change, and new pathogens (including avian influenza). ToR D focused upon bycatch. In support of WGBYC, this ToR aimed to contribute to the Roadmap for ICES PETS bycatch advice. ToR E involved liaison with other WGs. The Chairs of the newly-formed WGJCDP introduced to WGMME members, the Joint Cetacean Database Programme, which is to be hosted by the ICES Data Centre. The scope to collect information on other marine species besides cetaceans was discussed. A meeting with another newly formed ICES working group, on Marine Protected Areas, was planned but was deferred at the request of that group. On behalf of the working group, the Chairs would like to thank The Swedish Museum of Natural History for hosting the meeting

The understanding of the pathogenic mechanisms and the clinicopathological forms caused by currently circulating African swine fever virus (ASFV) isolates is incomplete. So far, most of the studies have been focused on isolates classified within genotypes I and II, the only genotypes that have circulated outside of Africa. However, less is known about the clinical presentations and lesions induced by isolates belonging to the other twenty-two genotypes. Therefore, the early clinicopathological identification of disease outbreaks caused by isolates belonging to, as yet, not well-characterised ASFV genotypes may be compromised, which might cause a delay in the implementation of control measures to halt the virus spread. To improve the pathological characterisation of disease caused by diverse isolates, we have refined the macroscopic and histopathological evaluation protocols to standardise the scoring of lesions. Domestic pigs were inoculated intranasally with different doses (high, medium and low) of ASFV isolate Ken05/Tk1 (genotype X). To complement previous studies, the distribution and severity of macroscopic and histopathological lesions, along with the amount and distribution of viral antigen in tissues, were characterised by applying the new scoring protocols. The intranasal inoculation of domestic pigs with high doses of the Ken05/Tk1 isolate induced acute forms of ASF in most of the animals. Inoculation with medium doses mainly induced acute forms of disease. A less severe but longer clinical course, typical of subacute forms, characterised by the presence of more widespread and severe haemorrhages and oedema, was observed in one pig inoculated with the medium dose. The severity of vascular lesions (haemorrhages and oedema) induced by high and medium doses was not associated with the amount of virus antigen detected in tissues, therefore these might be attributed to indirect mechanisms not evaluated in the present study. The absence of clinical signs, lesion

Hälsoundersökning av marina däggdjur

Whilst multiple countries in Europe have wildlife health surveillance (WHS) programmes, they vary in scope. In many countries, coordinated general surveillance at a national scale is not conducted and the knowledge of wildlife health status in Europe remains limited. Learning lessons from countries with established systems may help others to effectively implement WHS schemes. In order to facilitate information exchange, the WHS Network of the European Wildlife Disease Association organised a workshop to both collate knowledge and experience from countries that had started or expanded WHS programmes and to translate this information into practical recommendations. Presentations were given by invited representatives of European countries with different WHS levels. Events that led to the start-up and fostered growth spurts of WHS were highlighted, including action plan creation, partnership formation, organisation restructuring and appraisal by external audit. Challenges to programme development, such as a lack of funding, data sharing, infrastructural provision and method harmonisation, were explored. Recommendations to help overcome key challenges were summarised as: understanding and awareness; cross-sectoral scope; national-scale collaboration; harmonisation of methods; government support; academic support; other funding support; staff expertise and capacity; leadership, feedback and engagement; and threat mitigation and wildlife disease management. This resource may enable the development of WHS programmes in Europe and beyond.

After the re-introduction of African swine fever virus (ASFV) genotype II isolates into Georgia in 2007, the disease spread from Eastern to Western Europe and then jumped first up to Mongolian borders and later into China in August 2018, spreading out of control and reaching different countries of Southeast Asia in 2019. From the initial incursion, along with domestic pigs, wild boar displayed a high susceptibility to ASFV and disease development. The disease established self-sustaining cycles within the wild boar population, a key fact that helped its spread and that pointed to the wild boar population as a substantial reservoir in Europe and probably also in Asia, which may hinder eradication and serve as the source for further geographic expansion. The present review gathers the most relevant information available regarding infection dynamics, disease pathogenesis and immune response that experimental infections with different ASFV isolates belonging to genotype I and II in wild boar and feral pigs have generated. Knowledge gaps in areas such as disease pathogenesis and immune response highlights the importance of focusing future studies on unravelling the early mechanisms of virus-cell interaction and innate and/or adaptive immune responses, knowledge that will contribute to the development of efficacious treatments/vaccines against ASFV.

Since the late 1990s, high mortality and declining populations have been reported among sea birds including Herring gulls ( Larus argentatus) from the Baltic Sea area in Northern Europe. Repeated BoNT type C/D botulism outbreaks have occurred, but it remains unclear whether this is the sole and primary cause of mortality. Thiamine deficiency has also been suggested as a causal or contributing factor. With this study, we aimed to investigate gross and microscopic pathology in Herring gulls from affected breeding sites in Sweden in search of contributing diseases. Herring gulls from Iceland served as controls. Necropsies and histopathology were performed on 75 birds, of which 12 showed signs of disease at the time of necropsy. Parasites of various classes and tissues were commonly observed independent of host age, e.g. oesophageal capillariosis and nematode infection in the proventriculus and gizzard with severe inflammation, air sac larid pentastomes and bursal trematodiasis in pre-fledglings. Gross and microscopic findings are described. Notably, amyloidosis was diagnosed in 93 and 33% of the adult birds from Sweden and Iceland, respectively ( p<0.001), with more pronounced deposits in Swedish birds ( p<0.001). Gastrointestinal deposits were observed in the walls of arteries or arterioles, and occasionally in villi near the mucosal surface. Amyloid was identified within the intestinal lumen in one severely affected gull suggesting the possibility of oral seeding and the existence of a primed state as previously described in some mammals and chickens. This could speculatively explain the high occurrence and previously reported rapid onset of amyloidosis upon inflammation or captivity in Herring gulls. Amyloid-induced malabsorbtion is also a possibility. The Herring gull SAA/AA protein sequence was shown to be highly conserved but differed at the N-terminus from other avian species.

Lagoviruses belong to the Caliciviridae family. They were first recognized as highly pathogenic viruses of the European rabbit (Oryctolagus cuniculus) and European brown hare (Lepus europaeus) that emerged in the 1970–1980s, namely, rabbit haemorrhagic disease virus (RHDV) and European brown hare syndrome virus (EBHSV), according to the host species from which they had been first detected. However, the diversity of lagoviruses has recently expanded to include new related viruses with varying pathogenicity, geographic distribution and host ranges. Together with the frequent recombination observed amongst circulating viruses, there is a clear need to establish precise guidelines for classifying and naming lagovirus strains. Therefore, here we propose a new nomenclature based on phylogenetic relationships. In this new nomenclature, a single species of lagovirus would be recognized and called Lagovirus europaeus. The species would be divided into two genogroups that correspond to RHDV- and EBHSV-related viruses, respectively. Genogroups could be subdivided into genotypes, which could themselves be subdivided into phylogenetically well-supported variants. Based on available sequences, pairwise distance cutoffs have been defined, but with the accumulation of new sequences these cutoffs may need to be revised. We propose that an international working group could coordinate the nomenclature of lagoviruses and any proposals for revision.

The biliary trematode Pseudamphistomum truncatum parasitizes a wide range of fish-eating mammals, including humans. Here we report the emergence of this parasite in grey seals (Halichoerus grypus) in the Baltic Sea. One hundred eighty-three of 1 554 grey seals (11.9%) examined from 2002–2013 had detectable hepatobiliary trematode infection. Parasite identification was confirmed as P. truncatum by sequencing the ITS2 region of a pool of five to 10 trematodes from each of ten seals collected off the coast of seven different Swedish counties. The proportion of seals parasitized by P. truncatum increased significantly over time and with increasing age of seals. Males were 3.1 times more likely to be parasitized than females and animals killed in fishery interactions were less likely to be parasitized than animals found dead or hunted. There was no significant difference in parasitism of seals examined from the Gulf of Bothnia versus those examined from the Baltic Proper. Although the majority of infections were mild, P. truncatum can cause severe hepatobiliary disease and resulted in liver failure in at least one seal. Because cyprinid fish are the second intermediate host for opisthorchiid trematodes, diets of grey seals from the Baltic Sea were analysed regarding presence of cyprinids. The proportion of gastrointestinal tracts containing cyprinid remains was ten times higher in seals examined from 2008 to 2013 (12.2%) than those examined from 2002 to 2007 (1.2%) and coincided with a general increase of trematode parasitism in the host population. The emergence and relatively common occurrence of P. truncatum in grey seals signals the presence of this parasite in the Baltic Sea ecosystem and demonstrates how aquatic mammals can serve as excellent sentinels of marine ecosystem change. Investigation of drivers behind P. truncatum emergence and infection risk for other mammals, including humans, is highly warranted., Patologi hos säl