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•Different PCV2 genotypes circulated at low frequency until the 90s.•Farming strategy changes and international trade play important roles in PCV2 spread.•Three major genotypes have ...successively emerged during the last 20years.•Several recombinant clusters are distributed worldwide nowadays.•Recombination and immune derived selective pressure are important drivers of PCV2 evolution.
Since the first description of Porcine circovirus type 2 (PCV2), four genotypes (PCV2a, PCV2b, PCV2c and PCV2d) have been recognized and three of them have been shown to exhibit worldwide distribution. Here, the population dynamics of PCV2 has been reconstructed over time and the factors that have shaped its evolution determined. The results obtained confirm that PCV2 originated approximately at the beginning of the 20th century. The most recent common ancestor of genotypes PCV2a, PCV2b, PCV2c and PCV2d circulated in the 1950s, 1980s, 1960s and 1950s, respectively, and the population sizes of the individual genotypes remained low until the mid 90s, coinciding with the identification of PCV2 as a major pathogen of the pig industry.
The population dynamics of PCV2 have been characterized by the appearance of periodic waves of distinct genotypes that, after an initial rise, spread following major swine commercial routes and were then superseded by subsequent emerging genotypes. Various recombinant forms displayed comparable population dynamics and spreading routes to those of major genotypes, suggesting that recombinant strains are able to compete with parental ones. The capsid gene is subjected to immune selection and evasion of the host immune response seems to be a major force for the emergence and spread of new genotypes. In contrast, the evolution of other genes appears to be constrained by the particular genomic organization of PCV2. In summary, obtained results suggest that changes in farming strategies, international trade, host population immunity, recombination and the constraints imposed by genome organization have all played a major role in the evolutionary dynamics of PCV2.
Cystic echinococcosis (CE) is a neglected zoonosis caused by infection with the cestode Echinococcus granulosus sensu lato. We carried out a systematic literature review on E. granulosus s.l. human ...and animal (cattle, sheep, dog) infection in European Mediterranean and Balkan countries in 2000-2019, to provide a picture of its recent epidemiology in this endemic area. MEDLINE, EMBASE, Scopus, Google Scholar and Open Grey databases were searched. Included cases were: i) for humans, data from hospital records and imaging studies; ii) for dogs, data from necropsy and coprological studies; iii) for ruminants, cases based on slaughter inspection. The NUTS (Nomenclature of Territorial Units for Statistics) classification was used to categorize extracted data in epidemiological units, defined as data referred to one NUTS2 (basic region) in one year time. Data were then aggregated to NUTS1 level (major regions), calculating the average incidence value of included epidemiological units. For prevalence studies covering different epidemiological units, the pooled prevalence was estimated. Data were extracted from 79 publications, 25 on human infection (covering 437 epidemiological units), and 54 on animal infection (52 epidemiological units for cattle, 35 for sheep and 25 for dogs). At NUTS1 level, average annual incidence rates of human CE ranged from 0.10-7.74/100,000; pooled prevalence values ranged from 0.003-64.09% in cattle, 0.004-68.73% in sheep, and 0-31.86% in dogs. Southern and insular Italy, central Spain, Romania and Bulgaria reported the highest values. Bovine data showed a more similar pattern to human data compared to sheep and dogs. Limitation of evidence included the paucity of human prevalence studies, data heterogeneity, and the patchy geographical coverage, with lack of data especially for the Balkans. Our results confirm Italy, Spain, and Eastern Europe being the most affected areas, but data are extremely heterogeneous, geographical coverage very patchy, and human prevalence studies extremely scant. Results also highlight the notorious problem of underreporting of E. granulosus s.l. infection in both humans and animals.
Background
Feline parvovirus (FPV) is a common and potentially lethal infectious agent in cats.
Objective
To assess the prognostic value of age, neuter status, serum concentrations of serum amyloid A ...(SAA), haptoglobin, cholesterol and total thyroxine (tT4), and the presence of systemic inflammatory response syndrome (SIRS) in cats with panleukopenia.
Animals
Client‐owned cats with FPV infection diagnosed by a positive fecal ELISA test, positive PCR on feces or blood or both.
Methods
Retrospective cohort study. The electronic medical database was searched for cats with FPV infection presented between January 2010 and January 2018. Cats were divided into survivors and nonsurvivors according to their survival status 28 days after hospital admission. The prognostic importance of each variable was investigated univariately and by multivariable Cox's proportional‐hazards regression. Finally, receiver operator characteristic (ROC) curve analysis was used to identify the best cutoff value for discriminating survivors from nonsurvivors for the statistically significant prognostic predictors identified by multivariable analysis.
Results
Seventy cats were enrolled in the study. Multivariable analysis determined that only serum tT4 concentration at hospital admission was significantly (P = .01) associated with survival. A cutoff value of 0.82 μg/dL was identified by ROC curve analysis for serum tT4 concentration in discriminating survivors from nonsurvivors. Sensitivity at this cutoff was 73.9% and specificity was 82.9% (area under the curve, 0.783; 95% confidence interval, 0.668‐0.873; P < .0001).
Conclusion and Clinical Relevance
Serum tT4 concentration at hospital admission has prognostic value in cats with FPV infection.
Despite the fact that vaccine resistance has been typically considered a rare phenomenon, some episodes of vaccine failure have been reported with increasing frequency in intensively-raised ...livestock. Infectious bronchitis virus (IBV) is a widespread avian coronavirus, whose control relies mainly on extensive vaccine administration. Unfortunately, the continuous emergence of new vaccine-immunity escaping variants prompts the development of new vaccines. In the present work, a molecular epidemiology study was performed to evaluate the potential role of homologous vaccination in driving IBV evolution. This was undertaken by assessing IBV viral RNA sequences from the ORF encoding the S1 portion of viral surface glycoprotein (S) before and after the introduction of a new live vaccine on broiler farms in northern-Italy. The results of several biostatistics analyses consistently demonstrate the presence of a higher pressure in the post-vaccination period. Natural selection was detected essentially on sites located on the protein surface, within or nearby domains involved in viral attachment or related functions. This evidence strongly supports the action of vaccine-induced immunity in conditioning viral evolution, potentially leading to the emergence of new vaccine-escape variants. The great plasticity of rapidly-evolving RNA-viruses in response to human intervention, which extends beyond the poultry industry, is demonstrated, claiming further attention due to their relevance for animal and especially human health.
Members of the genus Circovirus are host-specific viruses, which are totally dependent on cell machinery for their replication. Consequently, certain mimicry of the host genome features is expected ...to maximize cellular replicative system exploitation and minimize the recognition by the innate immune system. In the present study, the analysis of several genome composition and codon bias parameters of circoviruses infecting avian and mammalian species demonstrated the presence of quite distinctive patterns between the two groups. Remarkably, a higher deviation from the expected values based only on mutational patterns was observed for mammalian circoviruses both at dinucleotide and codon levels. Accordingly, a stronger selective pressure was estimated to shape the genome of mammalian circoviruses, particularly in the Cap encoding gene, compared to avian circoviruses. These differences could be attributed to different physiological and immunological features of the two host classes and suggest a trade-off between a tendency to optimize the capsid protein translation while minimizing the recognition of the genome and the transcript molecules. Interestingly, the recently identified Porcine circovirus 3 (PCV-3) had an intermediate pattern in terms of genome composition and codon bias. Particularly, its Rep gene appeared closely related to other mammalian circoviruses (especially bat circoviruses) while the Cap gene more closely resembled avian circoviruses. These evidences, coupled with the high selective forces apparently modelling the PCV-3 Cap gene composition, suggest the potential recombinant origin, followed or preceded by a host jump, of this virus.
White striping (WS) is an alteration of breast and thigh muscles of broiler chickens characterized by the presence of white striations parallel to the direction of muscle fibers. This study was ...performed to evaluate the prevalence and the predisposing factors to WS in commercial broilers of different weight reared in northern Italy. Fifty seven broiler flocks, including animals of medium- and heavy-weight, were grossly evaluated at slaughter for the presence of WS. For each flock, breeding data (mean BW at slaughter, ADG, sex, color of skin and fat, genetic line, age, antibiotic treatment, and prevalence of deep pectoral myopathy) were collected and statistically analyzed to assess their correlation with WS. Histology of breast fillets affected by different grades of WS was performed to evaluate potential differences between medium- and heavy-weight broilers. The overall prevalence of WS in medium- and heavy-weight broilers (mean BW 2.59 ± 0.13 kg and 3.64 ± 0.34 kg, respectively) was 70.2 ± 7.9% and 82.51 ± 8.5%, respectively, while the percentage of severe WS was 13.3 ± 7.1% and 25.7 ± 12.8%, respectively. A strong correlation was found between presence of WS, BW at slaughter, and ADG (Pearson correlation = 0.69, P < 0.01; Pearson correlation = 0.67, P < 0.01). WS also closely correlated with the prevalence of deep pectoral myopathy (Spearman's Rho slaughterhouse 1 = 0.74, Spearman's Rho slaughterhouse 2 = 0.51, P < 0.01). No correlation was found between genetics or sanitary status of the flock and WS. Histology confirmed that breasts with WS lesions were affected by a polyphasic degenerative and necrotizing myopathy, and that the lesions, as expected, were more severe in heavy-weight broilers. In conclusion, WS is a major concern in commercial meat poultry reared in Italy, affecting more severely heavier broilers, and it is mainly related to the BW and ADG of animals.
Abstract
Background
Vector-borne zoonotic diseases are a concerning issue in Europe. Lyme disease and tick-borne encephalitis virus (TBEV) have been reported in several countries with a large impact ...on public health; other emerging pathogens, such as
Rickettsiales
, and mosquito-borne flaviviruses have been increasingly reported. All these pathogens are linked to wild ungulates playing roles as tick feeders, spreaders, and sentinels for pathogen circulation. This study evaluated the prevalence of TBEV,
Borrelia burgdorferi
sensu lato,
Rickettsia
spp.,
Ehrlichia
spp., and
Coxiella
spp. by biomolecular screening of blood samples and ticks collected from wild ungulates. Ungulates were also screened by ELISA and virus neutralization tests for flaviviral antibody detection.
Results
A total of 274 blood samples were collected from several wild ungulate species, as well as 406
Ixodes ricinus
, which were feeding on them. Blood samples tested positive for
B. burgdorferi
s.l. (1.1%; 0-2.3%) and
Rickettsia
spp. (1.1%; 0-2.3%) and showed an overall flaviviral seroprevalence of 30.6% (22.1–39.2%): 26.1% (17.9–34.3%) for TBEV, 3.6% (0.1–7.1%) for Usutu virus and 0.9% (0-2.7%) for West Nile virus. Ticks were pooled when possible and yielded 331 tick samples that tested positive for
B. burgdorferi
s.l. (8.8%; 5.8–11.8%),
Rickettsia
spp. (26.6%; 21.8–31.2%) and
Neoehrlichia mikurensis
(1.2%; 0-2.4%). TBEV and
Coxiella
spp. were not detected in either blood or tick samples.
Conclusions
This research highlighted a high prevalence of several tick-borne zoonotic pathogens and high seroprevalence for flaviviruses in both hilly and alpine areas. For the first time, an alpine chamois tested positive for anti-TBEV antibodies. Ungulate species are of particular interest due to their sentinel role in flavivirus circulation and their indirect role in tick-borne diseases and maintenance as
Ixodes
feeders and spreaders.
The genus Circovirus includes several species and mostly causes asymptomatic infections. Porcine circovirus 2 (PCV-2) and, with increasing evidence, Porcine circovirus 3 (PCV-3), have been associated ...with different clinical conditions all over the world. In 2019, a new porcine circovirus (PCV-4) was identified from diseased animals in China. Because of the lessons learned from PCV-2 and PCV-3, it appears mandatory to investigate the actual distribution of this new virus and its potential association with clinical outcomes. To this purpose, an exploratory study to detect PCV-4 by molecular methods was performed in Italy and Spain by testing more than 300 samples of different types (serum and tissues), collected from both healthy and diseased pigs and wild boar as well. All samples, independently from the country, type, health status and host, tested PCV-4 negative. Therefore, no evidence of PCV-4 presence was found in Italy and Spain through this exploratory study. Considering the dense pig trade among European countries, its presence in the continent can similarly be considered unlikely. The reasons behind the restricted PCV-4 distribution compared to other porcine circoviruses will require further investigations. Careful surveillance might nevertheless be important since prompt recognition of PCV-4 would allow the implementation of effective countermeasures to prevent its spreading and potential economic losses.
Successful reproductive performance is key to farm competitiveness in the global marketplace. Porcine parvovirus 1 (PPV1) has been identified as a major cause of reproductive failure, and since 2001 ...new species of porcine parvoviruses, namely PPV2-7, have been identified, although their role is not yet fully understood yet. The present study aimed to investigate PPVs' presence in reproductive failure outbreaks occurring in 124 farms of northern Italy. Fetuses were collected from 338 sows between 2019 and 2021 and tested for PPVs by real-time PCR-based assays and for other viruses responsible for reproductive disease. At least one PPV species was detected in 59.7% (74/124) of the tested farms. In order, PPV1, PPV5, PPV6, PPV7 and PPV4 were the most frequently detected species, whereas fewer detections were registered for PPV2 and PPV3. Overall, the new PPV2-7 species were detected in 26.6% (90/338) of the cases, both alone or in co-infections: PCV-2 (7.1%, 24/338), PCV-3 (8.2%, 28/338), and PRRSV-1 (6.2%, 21/338) were frequently identified in association with PPVs. Single PPVs detections or co-infections with other agents commonly responsible for reproductive failure should encourage future studies investigating their biological, clinical, and epidemiological role, for a better preparedness for potential emerging challenges in intensive pig production.
Aleutian mink disease virus (AMDV) is one the most relevant pathogens of domestic mink, where it can cause significant economic losses, and wild species, which are considered a threat to mink farms. ...Despite their relevance, many aspects of the origin, evolution, and geographic and host spreading patterns of AMDV have never been investigated on a global scale using a comprehensive biostatistical approach. The present study, benefitting from a large dataset of sequences collected worldwide and several phylodynamic-based approaches, demonstrates the ancient origin of AMDV and its broad, unconstrained circulation from the initial intercontinental spread to the massive among-country circulation, especially within Europe, combined with local persistence and evolution. Clear expansion of the viral population size occurred over time until more effective control measures started to be applied. The role of frequent changes in epidemiological niches, including different hosts, in driving the high nucleotide and amino acid evolutionary rates was also explored by comparing the strengths of selective pressures acting on different populations. The obtained results suggest that the viral passage among locations and between wild and domesticated animals poses a double threat to farm profitability and animal welfare and health, which is particularly relevant for endangered species. Therefore, further efforts must be made to limit viral circulation and to refine our knowledge of factors enhancing AMDV spread, particularly at the wild-domestic interface.
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