Seroprevalence and characterization of pestivirus infections in small ruminants and new world camelids in Switzerland

Abstract

The seroprevalence of pestivirus infections in small ruminants and new world camelids in Switzerland was determined. In 5'059 sera of sheep from 382 herds, 503 sera of goats from 54 herds and 109 sera of alpacas and lamas from 53 herds, population prevalences of 16.1% (sheep), 25.4% (goats) and 4.6% (new world camelids), respectively, were found. In order to determine the source of infection, the serological reactions were further characterized by cross-neutralization against two pestiviruses representing the genotypes BVDV (Bovine Virus Diarrhea Virus)-1 and BDV (Border Disease Virus)-1. Based on the ratio of respective antibody titres, 56.1% of the infections in sheep were induced by a BDV-1, 12.9% by a BVDV-1 and 31.0% by an unresolved pestivirus. In goats, the corresponding proportions were 23.4%, 10.2% and 66.4%, respectively. In Alpacas and Lamas, the source of infection of 1 animal was BDV-1 and that of 4 seropositive animals remained unresolved. In view of the phylogenetic relationship between pestiviruses, the unresolved source of infection is most probably attributable to other pestivirus genotypes circulating in small ruminants and new world camelids. Due to the predominance of pestiviral genotypes other than BVDV-1, the risk of transmission of BVDV from persistently infected small ruminants and new world camelids to cattle appears to be moderate, apart from close direct contact in mixed animal husbandry, communal pasturing and grazing in the Alps.

Influence of border disease virus (BDV) on serological surveillance within the bovine virus diarrhea (BVD) eradication program in Switzerland

“…In a study published in 1995, seroprevalence in registered sheep flocks of breeding associations and in large flocks was around 20 and 65%, respectively [22]. More recent data pointed to a slightly lower seroprevalence of 13.5% [23] or 16.1% [18] in sheep and 25.4% in goats [18]. In the latter study, it was demonstrated by means of cross-serum neutralisation tests (cross-SNT) that 9% of the sheep and 6% of the goats were infected with BDV.…”

Short communication: Transmission of border disease virus to seronegative cows inseminated with infected semen

“…SNT was used to identify the pestivirus specificity of the antibodies (Danuser et al, 2009; the BD virus type that was isolated from the bull calf was used instead of the Moredun type). As cross reactions between BVD and BD viruses are common based on their genetic relationship (Becher et al, 2003), only BD virus antibody titres at least four times higher than the BVD virus antibody titres were considered significantly higher (Braun et al, 2013;Danuser et al, 2009).All animals remained clinically inapparent with the exception of increased temperature (>39.0°C) on 1 or 2 days in 2 of 5 j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / r v s c inseminated cows and in the control cow, but only late after day 48. All of the five inseminated cows remained seronegative to day 7 after insemination ( Fig.…”

“…The optical density (OD) was expressed as percentage of the OD of a standard serum; relative OD readings between 20% and 30% were considered indeterminate and those >30% were considered positive. SNT was used to identify the pestivirus specificity of the antibodies (Danuser et al, 2009; the BD virus type that was isolated from the bull calf was used instead of the Moredun type). As cross reactions between BVD and BD viruses are common based on their genetic relationship (Becher et al, 2003), only BD virus antibody titres at least four times higher than the BVD virus antibody titres were considered significantly higher (Braun et al, 2013;Danuser et al, 2009).…”

Bovine Viral Diarrhea-an Emerging Disease in Camelids a Review

“…In the US several other researchers have isolated the 1b BVDV (Carman et al, 2005) but the same genotype was also found in alpacas in the UK (Anonymous, 2005;Fahmy, 1999c) and Switzerland (Danuser et al, 2009). Mueller and Broadbent (2007) reported that the oldest surviving PI alpaca survived 30 months.…”

“…Pestivirus infection has only been recently recognized as a potential cause of serious illness in both NWCs and OWCs (Evermann, 2006), indicating that members of the camelid group are susceptible to infection. In NWCs, Pestivirus has been intensively researched in North America (Byers, 2008;Kim et al, 2009), the UK (Mueller and Broadbent, 2007) as well as in Switzerland (Danuser et al, 2009). BVDV may cause a severe disease in alpacas and llamas, including diarrhea, reproductive loss, wastage and death, posing a significant threat to a herd's health as it does in bovines (Belknap et al, 2000).…”