International trades, local spread and viral evolution: The case of porcine circovirus type 2 (PCV2) strains heterogeneity in Italy

Franzo, Giovanni; Tucciarone, Claudia Maria; Dotto, Giorgia; Gigli, Alessandra; Ceglie, Letizia; Drigo, Michele

doi:10.1016/j.meegid.2015.04.004

Cited by 37 publications

(35 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Additionally, the exclusion of correlated SNPs hampered the definition of the genomic positions eventually involved in the escape process43. Finally, a widespread between farms PCV2 circulation has been reported in countries with a high pig production34 and consequently, even if the precise vaccination status was known in Reiner et al 43,. this paradoxically did not imply that the detected strains had not previously evolved in a vaccinated population.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Porcine circovirus type 2 (PCV2) evolution before and after the vaccination introduction: A large scale epidemiological study

Franzo

Tucciarone

Cecchinato

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

Since their commercialization, vaccines against Porcine circovirus type 2 (PCV2) have been the cornerstone control strategy. Nevertheless, the periodic emergence of new genotype waves and the recent reports of vaccine failure outbreaks have raised the question if widespread vaccination strategies could have driven viral evolution and affected different genotype fitness. To investigate this issue an in-deep analysis, based on a bioinformatics and biostatistics approach, has been implemented. ORF2 sequences from vaccinated and non-vaccinated populations (i.e. domestic pigs before and after vaccine introduction and wild boars) were considered. The action of selective forces on PCV2 strains has been analyzed and compared among groups. Remarkable differences were found in the selective forces acting on viral populations circulating in different “immune environments”. Particularly for PCV2a, a directional selection promoting a change in the viral capsid away from the vaccine specific antigenic determinants has been detected after vaccine introduction. Involved amino acids were previously reported to be part of viral epitopes whose variability is responsible of immune escape. Our findings support a change in PCV2 evolutionary pattern after widespread vaccination introduction and stress once more the compulsoriness of a continuous monitoring of PCV2 epidemiology to promptly act in response to the emergence of possible vaccine-escaping mutants.

show abstract

Section: Discussionmentioning

confidence: 99%

“…However, it is extremely challenging to recruit a significant number of farms where vaccination has not been applied for a long time despite PCV2 circulation. Additionally, contact network between farms is so dense that would be impossible to exclude the recent introduction of strains previously circulating in vaccinated farms34.…”

mentioning

confidence: 99%

Porcine circovirus type 2 (PCV2) evolution before and after the vaccination introduction: A large scale epidemiological study

Franzo

Tucciarone

Cecchinato

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although this genotype has a worldwide distribution [43], the most current prevalent genotype in the pig population is PCV2b [1, 44]. Indeed, it has been proposed that PCV2b is more prevalent than PCV2a in PCV2-SD cases and in vaccinated farms [45].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of natural porcine circovirus type 2 (PCV2) subclinical infection and seroconversion dynamics in piglets vaccinated at different ages

Oliver-Ferrando

Segalés

López-Soria

et al. 2016

Vet Res

View full text Add to dashboard Cite

This study aimed to determine the porcine circovirus type 2 (PCV2) serological and virological dynamics in piglets vaccinated at different ages in a PCV2 subclinical infection (PCV2-SI) scenario. Six hundred and forty-four 2 week-old healthy piglets were selected and distributed into four treatment groups: vaccination at 3, 6 or 10 weeks of age (3W-VAC, 6W-VAC and 10W-VAC groups, respectively) and unvaccinated pigs (NON-VAC group). Blood (n = 112 pigs) and oral fluid (OF) (n = 40 pens) samples were taken throughout the study to assess PCV2 load, humoral immunity and viral genotyping. Percentage of PCV2-DNA positive sera mainly raised by 10 weeks of age, being maximum at 14 weeks of age, and then started to decrease at 18 and 25 weeks of age. Specifically, PCV2 vaccination at 3 or 6 weeks of age yielded similar results, since they produced an earlier seroconversion and reduced, at different sampling points, the proportion of viremic animals in comparison to the unvaccinated group. In contrast, PCV2 vaccination at 10 weeks of age only achieved such reduction at 25 weeks of age; in this case, vaccination coincided with the increase of the percentage of viremic pigs in the population. Both serological techniques used in sera and OF offered similar results with a high and statistically significant correlation. In contrast, a higher percentage of PCV2 DNA positivity was detected in OF in comparison with sera. In conclusion, under the present study conditions, the optimal time for PCV2 piglet vaccination was at either 3 or 6 weeks of age.

show abstract

“…The spread of PCV2 can be viewed within the scope of international transmission through trading of pigs and pig products and also transmission among local herds. PCV2 has been confirmed to be transmitted through trading of live pigs with subclinical infection due to the subtle nature of the disease, which invariably calls for a more critical diagnostic check on imported animals or their products [5, 118]. There have been reported cases of transmission through selection of boars for breeding purposes and the importation of semen for the purpose of artificial insemination [119–121].…”

Section: Porcine Circovirus Type 2 (Pcv2)mentioning

confidence: 99%

Global Status ofPorcine circovirusType 2 and Its Associated Diseases in Sub-Saharan Africa

Afolabi

Iweriebor

Okoh

et al. 2017

Advances in Virology

View full text Add to dashboard Cite

Globally, Porcine circovirus type 2 (PCV2) is a recognized viral pathogen of great economic value in pig farming. It is the major cause of ravaging postweaning multisystemic wasting syndrome (PMWS) and many other disease syndromes generally regarded as Porcine circovirus associated diseases (PCVAD) in Europe. PCV2 infections, specifically PMWS, had impacted huge economic loss on swine production at different regions of the world. It has been studied and reported at different parts of the globe including: North and South America, Europe, Asia, Oceania, Middle East, and the Caribbean. However, till date, this virus and its associated diseases have been grossly understudied in sub-Sahara African region and the entire continent at large. Two out of forty-nine, representing just about 4% of countries that make up sub-Sahara Africa presently, have limited records on reported cases and occurrence of the viral pathogen despite the ubiquitous nature of the virus. This review presents an overview of the discovery of Porcine circovirus and its associated diseases in global pig herds and emphasizes the latest trends in PCV2 vaccines and antiviral drugs development and the information gaps that exist on the occurrence of this important viral pathogen in swine herds of sub-Saharan Africa countries. This will serve as wake-up call for immediate and relevant actions by stakeholders in the region.

show abstract

International trades, local spread and viral evolution: The case of porcine circovirus type 2 (PCV2) strains heterogeneity in Italy

Cited by 37 publications

References 34 publications

Porcine circovirus type 2 (PCV2) evolution before and after the vaccination introduction: A large scale epidemiological study

Porcine circovirus type 2 (PCV2) evolution before and after the vaccination introduction: A large scale epidemiological study

Evaluation of natural porcine circovirus type 2 (PCV2) subclinical infection and seroconversion dynamics in piglets vaccinated at different ages

Global Status ofPorcine circovirusType 2 and Its Associated Diseases in Sub-Saharan Africa

Contact Info

Product

Resources

About