Genotypic diversity of CSFV field strains: A silent risk reduces vaccination efficacy of CSFV vaccines in Vietnam

Nguyễn, Ngọc Hải; Phuong, Binh Nguyen Thi; Nguyen, Trung Quan; Tien, Duy; Thi, My Duyen Nguyen; Mai, Nguyen

doi:10.1016/j.virol.2022.04.002

“…Cases occurred on farms that recorded vaccination, this could be related to illegal movements of unvaccinated animals (52); and, they could also be a result of vaccination failures due to poor handling and malpractice as evidenced in Colombia (4,19). The risk associated with temperature in the spatiotemporal analysis, could be related to vaccination failures, as the vaccine cold-chain in regions such as the Amazon and the Coastal with average temperatures above 20 degrees Celsius, which corroborates that vaccination strategies alone are not sufficient to eradicate the dis-ease (53,54); possible antigenic alteration due to vaccination pressure and their effects on disease epidemiology could also be further analysed (55,56).…”

Section: Discussionmentioning

confidence: 87%

Risk factors and spatiotemporal analysis of classical swine fever in Ecuador

Acosta

¹

,

Dietze

²

,

Baquero

³

et al. 2022

Preprint

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Classical swine fever (CSF) is one of the most important re-emergent swine diseases worldwide. Despite concerted control efforts in the Andean countries, the disease remains endemic in several areas, limiting production and trade opportunities. In this study, we aim to determine herd-level risk factors and spatiotemporal implications associated with CSF. We analysed passive surveillance datasets and vaccination programmes from 2014 to 2020; Then, structured a herd-level case-control study using a multivariable logistic model containing 339 cases, and a spatiotemporal Bayesian model, considering 115 thousand premises, 2.3 million annual vaccine doses and a population of 1.6 million pigs distributed in 1,006 parishes. Our results showed that the risk factors that increased the odds of CSF occurrence were swill feeding (OR 9.28), time of notification (OR 2.18), animal entry in the last 30 days (OR 2.08), lack of CSF vaccination (OR 1.88), age of animals between 3-6 months (OR 1.58) and being in the coastal region (OR 1.87). Spatiotemporal models showed that the vaccination campaign reduced the risk by 33% while temperature increased the risk by 17%. The calculated priority index aims to facilitate the intervention process that should be focused on a couple of provinces, mainly in Morona Santiago and Los Rios as well as in specific parishes around the country. Our findings provide insight and understanding of the risk factors associated with CSF in Ecuador, which stands for the Andean region; even though the results are specific for the implementation of risk-based surveillance for CSF, data and methods could be valuable for the prevention and control of diseases such as African swine fever, or porcine reproductive and respiratory syndrome. In conclusion, the results highlight the complexity of the CSF control programme, the need to inform decision-makers, involve stakeholders and implement better strategies to update continental health policies to eradicate swine diseases.

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“…The first case of CSFV genotype 2.6 (historically classified as genotype 2.2) in South-East Asia was reported in 2001 from Thailand, and later from the neighboring countries [64][65][66]. The appearance and efficient spread of CSFV genotype 2.6 in Asia, likely from an ancestral CSFV strain that circulated in Italy in 1998, indicates the continuous evolution of CSFV in the region, reducing the effectiveness of the current vaccination efforts [67]. No reports of CSFV genotype 2 were present in South America before 2005.…”

Section: Discussionmentioning

confidence: 99%

Molecular and Pathological Characterization of Classical Swine Fever Virus Genotype 2 Strains Responsible for the 2013–2018 Outbreak in Colombia

Robert,

Goonewardene,

Lamboo

et al. 2023

Viruses

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Classical swine fever (CSF) is a highly contagious transboundary viral disease of domestic and wild pigs. Despite mass vaccination and continuous eradication programs, CSF remains endemic in Asia, some countries in Europe, the Caribbean and South America. Since June 2013, Northern Colombia has reported 137 CSF outbreaks, mostly in backyard production systems with low vaccination coverage. The purpose of this study was to characterize the virus responsible for the outbreak. Phylogenetic analysis based on the full-length E2 sequence shows that the virus is closely related to CSF virus (CSFV) genotype 2.6 strains circulating in Southeast Asia. The pathotyping experiment suggests that the virus responsible is a moderately virulent strain. The 190 nucleotide stretch of the E2 hypervariable region of these isolates also shows high similarity to the CSFV isolates from Colombia in 2005 and 2006, suggesting a common origin for the CSF outbreaks caused by genotype 2.6 strains. The emergence of genotype 2.6 in Colombia suggests a potential transboundary spread of CSFV from Asia to the Americas, complicating the ongoing CSF eradication efforts in the Americas, and emphasizes the need for continuous surveillance in the region.

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“…Some cases occurred on premises with previous vaccination records, possibly related to illegal movements of unvaccinated animals [ 47 ] or vaccination failures because of poor handling and mismanagement, as evidenced in neighbouring Colombia [ 4 , 20 ]. The risk associated with higher temperatures in the spatiotemporal analysis could also be linked to problems in the vaccine cold-chain in regions such as the Amazon and the coast, which represent a logistical challenge when addressing average temperatures above 20 degrees Celsius, corroborating that vaccination strategies alone may not eradicate the disease [ 58 , 59 ]; Furthermore, possible antigenic alterations because of vaccination pressure and their effects on the epidemiology of the disease could also be further analysed [ 60 , 61 ].…”

Section: Discussionmentioning

confidence: 99%

Risk Factors and Spatiotemporal Analysis of Classical Swine Fever in Ecuador

Acosta

¹

,

Dietze²,

Baquero³

et al. 2023

Viruses

View full text Add to dashboard Cite

Classical swine fever (CSF) is one of the most important re-emergent swine diseases worldwide. Despite concerted control efforts in the Andean countries, the disease remains endemic in several areas, limiting production and trade opportunities. In this study, we aimed to determine the risk factors and spatiotemporal implications associated with CSF in Ecuador. We analysed passive surveillance and vaccination campaign datasets from 2014 to 2020; Then, we structured a herd-level case–control study using a logistic and spatiotemporal Bayesian model. The results showed that the risk factors that increased the odds of CSF occurrence were the following: swill feeding (OR 8.53), time until notification (OR 2.44), introduction of new pigs during last month (OR 2.01) and lack of vaccination against CSF (OR 1.82). The spatiotemporal model showed that vaccination reduces the risk by 33%. According to the priority index, the intervention should focus on Morona Santiago and Los Rios provinces. In conclusion, the results highlight the complexity of the CSF control programs, the importance to improve the overall surveillance system and the need to inform decision-makers and stakeholders.

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Genotypic diversity of CSFV field strains: A silent risk reduces vaccination efficacy of CSFV vaccines in Vietnam

Cited by 3 publications

References 27 publications

Risk factors and spatiotemporal analysis of classical swine fever in Ecuador

Risk factors and spatiotemporal analysis of classical swine fever in Ecuador

Molecular and Pathological Characterization of Classical Swine Fever Virus Genotype 2 Strains Responsible for the 2013–2018 Outbreak in Colombia

Risk Factors and Spatiotemporal Analysis of Classical Swine Fever in Ecuador

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