Pre-screening of crude peptides in a serological bead-based suspension array.

Most serological assays detect antibody responses in biological samples through affinity of serum antibodies for antigens provided in the assay. Certain antigens, however, may be difficult to produce and/or may contain unwanted epitopes. In these cases, a practical alternative may be the use of peptides as representatives for specific epitopes.

Influence of Age and Dose of African Swine Fever Virus Infections on Clinical Outcome and Blood Parameters in Pigs.

African swine fever (ASF) is a fatal disease for domestic pigs, leading to serious economic losses in countries where ASF is endemic. Despite extensive research, efficient vaccines against ASF are lacking. Since peripheral blood cells are important mediators for vaccines, we study the impact of ASF on blood parameters in pigs with different ages and infected with different doses of ASF virus.

High turnover drives prolonged persistence of influenza in managed pig herds.

Pigs have long been hypothesized to play a central role in the emergence of novel human influenza A virus (IAV) strains, by serving as mixing vessels for mammalian and avian variants. However, the key issue of viral persistence in swine populations at different scales is ill understood. We address this gap using epidemiological models calibrated against seroprevalence data from Dutch finishing pigs to estimate the 'critical herd size' (CHS) for IAV persistence.

No evidence of African swine fever virus replication in hard ticks.

African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in Europe, Ixodes ricinus and Dermacentor reticulatus, have not been assessed for their vector competence for ASFV.

Seroprevalence of Schmallenberg virus antibodies among dairy cattle, the Netherlands, winter 2011-2012.

Infections with Schmallenberg virus (SBV) are associated with congenital malformations in ruminants. Because reporting of suspected cases only could underestimate the true rate of infection, we conducted a seroprevalence study in the Netherlands to detect past exposure to SBV among dairy cattle. A total of 1,123 serum samples collected from cattle during November 2011-January 2012 were tested for antibodies against SBV by using a virus neutralization test; seroprevalence was 72.

Classical swine fever and avian influenza epidemics: lessons learned.

Experience with recent large-scale epidemics of Classical Swine Fever and Avian Influenza--among others in the Netherlands--have teached us several lessons that should prepare us better for future outbreaks. Among others, improving early detection of outbreaks--by using syndrome surveillance systems--is a key factor, in which farmers and veterinary practitioners have an imminent role. A major step in this respect is facilitation of the use of exclusion diagnostics without closing down the farm in clinical situations with non-specific clinical signs observed in sick animals.

The effect of tissue degradation on detection of infectious virus and viral RNA to diagnose classical swine fever virus.

A considerable part of tissue samples that are collected for the monitoring of classical swine fever (CSF) from the wild boar population or from domestic pigs are unsuitable for virus detection using the fluorescent antibody test (FAT) or virus isolation (VI), due to tissue degradation. Reverse transcription polymerase chain reaction (RT-PCR) has a higher sensitivity than the FAT and VI, and is supposed to be less sensitive to sample degradation. Reliable and quantitative information on how long viral RNA and infectious virus can be detected in organs and which organs are most susceptible to degradation is, however, lacking.

Quantification of classical swine fever virus in aerosols originating from pigs infected with strains of high, moderate or low virulence.

During epidemics of classical swine fever (CSF), the route of virus introduction into a farm is often unclear. One of the suggested routes is via the air. Under experimental conditions, airborne transmission over a short distance seems possible, but analysis of outbreak data is still inconclusive.

Survival of classical swine fever virus at various temperatures in faeces and urine derived from experimentally infected pigs.

Indirect transmission of classical swine fever virus (CSFV) can occur through contact with mechanical vectors, like clothing and footwear or transport vehicles, contaminated with the secretions or excretions of infected pigs. A prerequisite for indirect transmission is survival of the virus on the mechanical vector. Consequently, to obtain more insight into these transmission routes, it is important to know how long the virus remains viable outside the host.

Detection and quantification of classical swine fever virus in air samples originating from infected pigs and experimentally produced aerosols.

During epidemics of classical swine fever (CSF), neighbourhood infections occurred where none of the 'traditional' routes of transmission like direct animal contact, swill feeding, transport contact or transmission by people could be identified. A hypothesized route of virus introduction for these herds was airborne transmission. In order to better understand this possible transmission route, we developed a method to detect and quantify classical swine fever virus (CSFV) in air samples using gelatine filters.