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The article discusses a study which describes a ring trial conducted by 10 European laboratories for the detection of Classical swine fever virus (CSFV). Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) protocols and a standardized protocol commonly used by the Friedrich-Loeffler-Institute (FLI) were used for this ring trial. Results of the trial showed that the real-time RT-PCR assay is a rapid and extremely sensitive tool for the detection of CSFV.

Abstract: Classical swine fever (CSF) is among the most important diseases of domestic pigs and causes great socio-economic losses. Therefore, control of CSF is given high priority within the European Union, including financial support of concerted control actions in candidate and in potential candidate countries. Unfortunately, from some of these countries information on the CSF situation and related data is very limited. This study was undertaken to gather all available information on the domestic pig population and husbandry, and of the CSF situation in domestic pigs and wild boar in South-Eastern European countries that have recently joined or are applying to join the European Union. A characteristic feature of pig production in Eastern Europe is that most of them are in backyard holdings. Although mandatory vaccination is carried out in most of these countries, sporadic CSF outbreaks still occur. Little is still known about the CSF situation in wild boar. In addition, molecular epidemiology of 97 CSF virus isolates available from these countries, from outbreaks that occurred between 1994 and 2007, was performed. Most of the isolates were from Romania and Bulgaria. Genetic typing showed that almost all isolates (with exception of Croatian and of the Macedonian isolates) belonged to genotype 2.3. On the basis of these sequences, and additional sequences from outbreaks in Eastern and Western European countries taken from the database held at the European Union Reference Laboratory (EURL), two clusters could be distinguished within subtype 2.3. They were tentatively named 2.3.1 and 2.3.2. [ABSTRACT FROM AUTHOR]

During a period of 5 years (1997–2001) several outbreaks of classical swine fever (CSF) were recorded in Croatia. For genetic typing, fragments of 150 nucleotides within the 5′-non-translated region (5′-NTR) and 190 nucleotides within the E2 glycoprotein coding gene of nine field isolates that were derived from domestic pigs and wild boars were used. For better epizootiological understanding, isolates from other European countries were included in the study. The results show that the isolates belong to subgroups 2.1 and 2.3 of CSF virus. Isolates from subgroup 2.1 were collected from domestic pigs during sporadic outbreaks in June 1997 and are genetically closely related. A genomic similarity between these isolates and CSF virus isolates from pigs in other European countries from the same year could also be confirmed. In contrast, the isolate from October 1997 was found to be a member of subgroup 2.3, and is closely related to European CSF virus isolates from outbreaks in the last decade in Western and Central European countries. These results show that two different sources of CSF virus caused outbreaks in Croatia during the same year. Furthermore, a close relationship was found between an isolate from a domestic pig in 1999 and isolates of subgroup 2.3 that originated from Croatian wild boars. [Copyright &y& Elsevier]

The heat-stable live-attenuated classical swine fever virus (CSFV) vaccine is an urgent need in many countries of Asia, Europe and Latin America. In this study, the thermostability of lyophilized live-attenuated CSFV vaccine formulations were investigated using accelerated stability at 37 °C for 10 days. The freeze-dried heat-stable formulation ST16, containing excipient combinations of trehalose, glycine, thiourea and phosphate buffer shows the superior thermostability. Moreover, the lyophilized vaccine with formula ST16 kept loss of viral activity less than 0.5 log 10 during 24 months at storage temperatures of 2-8 °C. In thermal study, ST16 stabilized the vaccine within 1.0 log 10 loss after storage at up to 25 °C for 6 months and room temperature for 7 months. Even under the harshest storage conditions of 37 °C for 25 days and 45 °C for 2 weeks, the virus titer dropped less than 1.0 log 10 using ST16. Besides, it is notable that ST16 excluded gelatin and exogenous proteins, which might cause allergic reactions, thus avoiding immune side effects. The vaccine formulated ST16 proved to be safe and effective when immunized to piglets in vivo. The characteristics of dried vaccines were analyzed by X-ray powder diffraction, residual water measurements, differential scanning calorimetry and it was found that vaccine antigen were preserved in an amorphous matrix with high glass transition temperature above 60 °C and low residual water content below 2%, which made the vaccine more stable during storage., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)