Selection of European Union standard reference sera for use in the serological diagnosis of infectious bovine rhinotracheitis

Abstract

Selection of European Union standard reference sera for use in the serological diagnosis of infectious bovine rhinotracheitis B. PERRIN (1) , T. CALVO (2) , P. CORDIOLI (3) , M. COUDERT (1) , S. EDWARDS (4) , M. ELOIT (s) , B. GUÉRIN (6) , J.A. KRAMPS (7) , P. LENIHAN (8) , E. PASCHALERI (9) , M. PERRIN (1) , J. SCHON (10) , J.-T. VAN OIRSCHOT (7) , E. VANOPDENBOSCH (11) , G. WELLEMANS (11) , G. WIZIGMANN (12) and M. THIBIER (6) Summary: A study, consisting of three trials, was undertaken in order to find standard reference sera for use in serological diagnostic procedures for infectious bovine rhinotracheitis (IBR) in the European Union (EU). A total of forty-nine laboratories participated in the trials, in which panels of positive, weak positive, and negative candidate sera were tested blind by neutralisation, indirect and blocking enzyme-linked immunosorbent assay, indirect immunofluorescence and passive haemagglutination. A serum which scored positive in all tests in all laboratories was selected as a strong positive standard serum. The chosen negative standard serum gave negative results in virtually all tests. A 1/36 dilution of a positive serum was chosen as the weak positive standard serum and only very sensitive techniques were able to score it positive. Three EU reference sera are now available for the standardisation of serological tests for IBR.

Serum neutralization with different types and subtypes of bovine herpesvirus 1 and 5

“…Nonetheless, ELISAs for antibodies to bovine herpesviruses should have their validation parameters redefined with sera tested against a wider number of viruses. This might reveal that perhaps many of the discrepancies found between results of SN and ELISAs may in fact be due to SN's low sensitivity, what becomes evident particularly when tests are performed and compared within different laboratories (Perrin et al 1993, 1994, Kramps et al 1996. As previously reported, SN with a 24 hour incubation (Bitsch 1978, Perrin et al 1993) is expected to be more sensitive than the one hour incubation SN.…”

“…Particularly where eradication is to be achieved, and in view of the particularities of herpesvirus latency, false negative results might miss a significant population of potential virus shedders, thus compromising eradication policies and perpetuating the infection in flocks. Moreover, in situations were seronegativity is a mandatory requirement such as in the international trade of animals (Perrin et al 1993, 1994, Kramps et al 1996, Van Oirschot 2000, regulatory organs …”

“…However, the actual degree of serologic cross-reactivity induced by such viruses has not been evaluated in detail. Most diagnostic and research laboratories rely on SN tests with a single challenge virus -usually a BoHV-1.1 strain -to evaluate serological responses to bovine herpesviruses (Perrin et al 1993, 1994, Kramps et al 1996, Van Oirschot 2000. As both virus types (and most subtypes) may circulate in herds, the choice of a challenge virus may significantly influence the test's sensitivity (defined here as the capacity to detect positive sera within a population of serum samples).…”

Bovine herpesvirus-1 (BHV-1) – a re-emerging concern in livestock: a revisit to its biology, epidemiology, diagnosis, and prophylaxis

“…Secondary immune responses are characterized primarily by the formation of IgG 2 antibody. The VNT has been widely used and is the gold standard by which other techniques have been evaluated (Perrin et al 1996). However, the ELISA is a specific, sensitive, and more practical test for detection of BHV-1 antibodies.…”

Genetic immunisation of cattle against Bovine herpesvirus 1: glycoprotein gD confers higher protection than glycoprotein gC or tegument protein VP8

“…Virus neutralising antibody titres (VNT) were determined in a microtitration system as previously described [20]. BoHV-1-specific antibody titres were determined with a home-made indirect ELISA system proven to be efficient in a compared ring trial [24,42]. Briefly, a BoHV-1 antigen and a control preparation were prepared by sonicating lysates of BV158-infected or mockinfected MDBK cells before an incubation of 2 h at RT in 0.5% non-ionic detergent IGEPAL CA-630 (Sigma-Aldrich).…”