title: Tick-borne encephalitis virus (TBEV) - findings on cross reactivity and longevity of TBEV antibodies in animal sera.
abstract: BACKGROUND
  By using animal sera as sentinels, natural TBEV foci could be identified and further analyses including investigations of ticks could be initiated. However, antibody response against TBEV-related flaviviruses might adversely affect the readout of such a monitoring. Therefore, the cross-reactivity of the applied TBEV serology test systems - enzyme linked immunosorbent assay (ELISA) and virus neutralization test (VNT) - as well as the longevity of TBEV antibody titres in sheep and goats were investigated in this study.
  
  
  RESULTS
  Cross-reactivity of the TBEV antibody test systems with defined antibody-positive samples against selected members of the Flaviviridae family (e.g. Louping ill virus, West Nile virus) was observed for Louping-ill-positive sera only. In contrast, the commercial West Nile virus (WNV) competitive ELISA showed a high level of cross-reactivity with TBEV-specific positive sera.To assess the longevity of TBEV antibody titres, sera from two sheep and two goats, which had been immunized four times with a commercially available TBEV vaccine, were tested routinely over 28 months. In three of the four animals, TBEV-specific antibody titres could be detected over the whole test period.In addition, sera from the years 2010 and 2011 were collected in flocks in different villages of Baden-Württemberg and Thuringia to allow re-examination two to four years after the initial analysis. Interestingly, in most cases the results of the former investigations were confirmed, which may be caused by steadily existing natural TBEV foci.
  
  
  CONCLUSIONS
  Cross-reactivity must be taken into consideration, particularly for TBEV serology in regions with a prevalence of Louping ill virus and for serological testing of WNV by cross-reactive ELISAs. Furthermore, over-interpretation of single TBEV-positive serological results should be avoided, especially in areas without a TBEV history.
authors.affiliation: Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str, 96a, D-07743 Jena, Germany. DrChristineKlaus@gmail.com.
authors.forename: Christine
authors.initials: C
authors.lastname: Klaus
authors.forename: Ute
authors.initials: U
authors.lastname: Ziegler
authors.forename: Donata
authors.initials: D
authors.lastname: Kalthoff
authors.forename: Bernd
authors.initials: B
authors.lastname: Hoffmann
authors.forename: Martin
authors.initials: M
authors.lastname: Beer
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology; D004669:Encephalitis Viruses, Tick-Borne / Q000276:immunology*; D004675:Encephalitis, Tick-Borne / Q000276:immunology / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D015511:Goat Diseases / Q000276:immunology / Q000821:virology; D006041:Goats / Q000276:immunology / Q000821:virology; D006734:Horse Diseases / Q000276:immunology / Q000821:virology; D006736:Horses / Q000276:immunology / Q000821:virology; D008297:Male; D009500:Neutralization Tests / Q000662:veterinary; D012756:Sheep / Q000276:immunology / Q000821:virology; D012757:Sheep Diseases / Q000276:immunology / Q000821:virology; D013987:Ticks / Q000821:virology; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral