Surveillance of Sarcoptic Mange in Iberian Ibexes (Capra pyrenaica) and Domestic Goats (Capra hircus) in Southern Spain.

Sarcoptic mange is a highly contagious skin disease caused by Sarcoptes scabiei. Sera were collected from 411 Iberian ibexes, comprising 157 individuals with sarcoptic mange skin lesions and 254 clinically healthy animals, in 13 population nuclei across Andalusia (southern Spain) between 2015 and 2021. Skin samples from 88 of the 157 animals with mange-compatible lesions were also obtained. Moreover, 392 serum samples from domestic goats (Capra hircus) were collected in the same region and study period. Antibodies against S. scabiei were tested using an in-house indirect ELISA, while the presence of mites of S. scabiei was evaluated in the skin samples by potassium hydroxide digestion. Seropositivity was found in eight (3.1%) of the clinically healthy ibexes and in 104 (66.2%) of the animals with mange-compatible lesions. The presence of S. scabiei was confirmed in 57 (64.8%) out of the 88 skin samples analysed and anti-S. scabiei antibodies were found in 49 (86.0%) of these 57 mite-positive individuals. Seropositive animals were detected in population nuclei with previous records of sarcoptic mange, where S. scabiei mites were detected by potassium hydroxide digestion in individuals with sarcoptic mange-compatible external lesions. However, seropositivity was not observed in population nuclei that were historically free of this disease. None of the 392 domestic goats had antibodies against S. scabiei, suggesting an independent epidemiological cycle of sarcoptic mange in Iberian ibex populations in the study area, and a limited or null role of domestic goats in the transmission of the parasite to this wild species. Overall, our findings underscore the importance of maintaining and/or implementing integrated surveillance programs and control strategies in wildlife and livestock, to limit the risk of S. scabiei circulation in Iberian ibex populations.

Mitochondrial genetic diversity and phylogenetic relationships of Echinococcus multilocularis in Europe.

The cestode Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a fatal zoonotic parasitic disease of the northern hemisphere. Red foxes are the main reservoir hosts and, likely, the main drivers of the geographic spread of the disease in Europe. Knowledge of genetic relationships among E. multilocularis isolates at a European scale is key to understanding the dispersal characteristics of E. multilocularis. Hence, the present study aimed to describe the genetic diversity of E. multilocularis isolates obtained from different host species in 19 European countries. Based on the analysis of complete nucleotide sequences of the cob, atp6, nad2, nad1 and cox1 mitochondrial genes (4,968 bp), 43 haplotypes were inferred. Four haplotypes represented 62.56 % of the examined isolates (142/227), and one of these four haplotypes was found in each country investigated, except Svalbard, Norway. While the haplotypes from Svalbard were markedly different from all the others, mainland Europe appeared to be dominated by two main clusters, represented by most western, central and eastern European countries, and the Baltic countries and northeastern Poland, respectively. Moreover, one Asian-like haplotype was identified in Latvia and northeastern Poland. To better elucidate the presence of Asian genetic variants of E. multilocularis in Europe, and to obtain a more comprehensive Europe-wide coverage, further studies, including samples from endemic regions not investigated in the present study, especially some eastern European countries, are needed. Further, the present work proposes historical causes that may have contributed to shaping the current genetic variability of E. multilocularis in Europe.

A highly endemic area of Echinococcus multilocularis identified through a comparative re-assessment of prevalence in the red fox (Vulpes vulpes), Alto Adige (Italy: 2019-2020).

Surveillance of Echinococcus multilocularis at the edge of its range is hindered by fragmented distributional patterns and low prevalence in definitive hosts. Thus, tests with adequate levels of sensitivity are especially important for discriminating between infected and non-infected areas. In this study we reassessed the prevalence of E. multilocularis at the southern border of its distribution in Province of Bolzano (Alto Adige, northeastern Alps, Italy), to improve surveillance in wildlife and provide more accurate estimates of exposure risk. We compared the diagnostic test currently implemented for surveillance based on coproscopy and multiplex PCR (CMPCR) to a real-time quantitative PCR (qPCR) in 235 fox faeces collected in 2019 and 2020. The performances of the two tests were estimated using a scraping technique (SFCT) applied to the small intestines of a subsample (n = 123) of the same foxes as the reference standard. True prevalence was calculated and the sample size required by each faecal test for the detection of the parasite was then estimated. True prevalence of E. multilocularis in foxes (14.3%) was markedly higher than reported in the last decade, which was never more than 5% from 2012 to 2018 in the same area. In addition, qPCR showed a much higher sensitivity (83%) compared to CMPCR (21%) and agreement with the reference standard was far higher for qPCR (0.816) than CMPCR (0.298) meaning that for the latter protocol, a smaller sample size would be required to detect the disease. Alto Adige should be considered a highly endemic area. Routine surveillance on definitive hosts at the edges of the E. multilocularis distribution should be applied to smaller geographic areas, and rapid, sensitive diagnostic tools using directly host faeces, such as qPCR, should be adopted.

Sarcoptic Mange in Wild Caprinae of the Alps: Could Pathology Help in Filling the Gaps in Knowledge?

Sarcoptic mange represents the most severe disease for wild Caprinae individuals and populations in Europe, raising concerns for both conservation and management of these ungulates. To date, this disease has been investigated in different wild caprine species and under many different perspectives including diagnostics, epidemiology, impact on the host populations, and genetics of both hosts and parasite, with the aim to disentangle the host-Sarcoptes scabiei relationship. Notwithstanding, uncertainty remains and basic questions still need an answer. Among these are the effect of immune responses on mange severity at an individual level, the main drivers in host-parasite interactions for different clinical outcomes, and the role of the immune response in determining the shift from epidemic to endemic cycle. A deeper approach to the pathology of this disease seems therefore advisable, all the more reason considering that immune response to S. scabiei in wild Caprinae, generally classified as a hypersensitivity, remains poorly understood. In this paper, we reviewed the pathological features associated to sarcoptic mange in wildlife, exploring different kinds of hypersensitivity and outcomes, with the objective of highlighting the major drivers in the different responses to this disease at an individual level and proposing some key topics for future research, with a particular attention to Alps-dwelling wild caprines.

Insight into an outbreak of Salmonella Choleraesuis var. Kunzendorf in wild boars.

An unusual mortality of wild boars occurred in Italy from 2012 to 2015 due to Salmonella Choleraesuis infection. In order to confirm the occurrence of an outbreak of S. Choleraesuis in wild boars and to epidemically characterise the unique S. Choleraesuis biovar, a collection of isolates belonging to wild boars was investigated from the phenotypic, molecular and genomic points of view (PFGE and WGS). Moreover, the possibility of transmission to domestic pigs and humans, temporally and geographically close to the wild boar epidemic, was tested by also including in the panel isolates from infected domestic pigs and from one human case of infection. Wild boar isolates displayed a high genetic correlation, thus suggesting they are part of the same outbreak, with a common invasiveness potential. Conversely, no correlation between pig isolates and those from the other sources (wild boars and human) was found. However, the phylogenetic and PFGE analyses suggest a high degree of similarity between the human and the investigated wild boar outbreak isolates, implying the potential for the spread of Salmonella Choleraesuis among these species.

Infracommunity crowding as an individual measure of interactive-isolationist degree of parasite communities: disclosing the effects of extrinsic and host factors.

BACKGROUND: Interactions between parasite species within a host play a fundamental role in shaping parasite communities that have been classified within a continuum between interactive and isolationist. Interactive communities are principally structured by interactions between parasite species, while isolationist communities are structured by processes independent of the presence of other parasite species. Assessing whether, and to what extent, parasite communities exist along this continuum has been challenging due to a lack of an index that quantifies the degree of interactivity. Moreover, the absence of an index at the individual host level has made it unfeasible to identify host and extrinsic factors that may influence the degree of interactivity of a parasite community. METHODS: Here we propose an infracommunity crowding index that can reflect the degree of interactivity of a parasite community within each individual. This index quantifies the mean number of parasites that the average parasite within a community is exposed to, including the different aspects of parasite communities important in determining the level of interactivity, i.e. total abundance, species richness and evenness. We applied this analytical approach to the abomasal parasite communities of three alpine ruminant species that are traditionally viewed as isolationist. RESULTS: The application of our index to abomasal parasite communities shows that the majority of parasites live in highly crowded communities, suggesting that these host species harbour interactive parasite communities. In addition, the infracommunity crowding was highly variable and influenced by the host species, as well as by the timing of sampling and host age and sex. CONCLUSIONS: Despite increasing evidence on the influence of interactions between parasite species in shaping infections, an analytical measure to quantify the degree of interactivity of parasite communities is lacking. Here we present a new analytical approach which, when applied to parasite communities, appears to be sensitive to both extrinsic and host factors, highlighting that the degree of interactivity is not a static and specific feature of host species, but rather a dynamical process that keeps evolving during host's life. The new index provides opportunities for further investigations aimed at revealing the determinants of parasite interactivity.

Abomasal nematode community in an alpine chamois (Rupicapra r. rupicapra) population before and after a die-off.

Abomasa of 185 chamois shot during 5 consecutive hunting seasons were collected as part of a health monitoring program in an alpine area of Italy and examined for nematodes. The data were obtained during both the preceding period and that following a severe die-off caused by a pneumonia outbreak. Prevalence, mean abundance, mean intensity, and Thul Importance index were consistently high, in particular for Haemonchus contortus, having a low host specificity and high pathogenic potential. Species typical of cervids were also consistently detected. The abomasal nematode community showed an isolationist structure, suggesting its composition was primarily determined by external factors such as interspecific interaction among host species and environmental conditions. The effect of different factors (host sex, sampling site, and time) on nematode counts and aggregation were analyzed and discussed considering the peculiarities of the study site and the chamois population crash. In the light of parallel results for health monitoring, abomasal parasitism could represent a predisposing factor for the observed die-off.