Untersuchungen zum Nachweis des bovinen Herpesvirus Typ 1 (BHV1) mittels Intrakutantest II. Mitteilung: Experimentelle Untersuchungen

Abstract

Summary Investigations concerning the proof of BHV1 infection by an intradermal test II. Experiments A purified concentrated BHV1 antigen that had been tested in field trials was also tested under isolated conditions in BHV1 positive and negative cattle. The antigen proved to act specifically even after storage for 2 years at + 4 °C or for 6 months at 37 °C. The best results were obtained when the test was read 48–72 hours after the injection, which is in agreement with the field trials. The increase in skin thickness decreased unless boostered by infection or vaccination gradually. The test is unsuitable to control a vaccination programme. There was no correlation between the increase in thickness and humoral antibody titers. Repeated application of the intradermal injection of the antigen did not result in seroconversion in seronegative cattle. The biological limits of the test evaluation are discussed. Zusammenfassung Ein in Praxisversuchen bereits erprobtes, konzentriertes und gereinigtes BHV 1‐Intrakutantest‐antigen wurde in Experimenten unter isolierter Haltung an BHV 1‐seropositiven und ‐seronegativen Rindern geprüft. Die Untersuchungen ergaben Spezifität, mindestens 2jährige Haltbarkeit und über 6 Monate Thermostabilität bei bis zu 37 °C. In Übereinstimmung mit den Ergebnissen vorangegangener Feldversuche war der beste Kontrollzeitpunkt der Hautdickenzunahme am 2. und 3. Tag nach Testansatz. Die Hautdickenzunahme von BHV 1‐infizierten Rindern nahm ohne deren Boostermöglichkeit in zahlreichen Einzelfällen mit zunehmendem Abstand vom Infektionstermin ab. Zur Kontrolle eines BHV 1‐Impferfolges war der Intrakutantest nicht geeignet. Eine Korrelation zwischen Stärke der Hautdickenzunahme und Höhe der Antikörpertiter beim Einzeltier wurde nicht beobachtet. Eine wiederholte Anwendung des Intrakutantestes bei BHV 1‐negativen Rindern führte nicht zur Stimulation zellvermittelter oder humoraler Antikörper. Die biologisch bedingten Grenzen der Testbewertung werden diskutiert.

An Intradermal Test for the Diagnosis of BHV‐1 Infection. The Effect of Repeated Testing on the Immune Status of Cattle

“…O u r data are in agreement with those by STRAUB et al (1990) who in experiment performed on 6 seronegative calves and 3 with passively acquired antibodies, found that sixtuple administration of the antigen between 3 and 67 weeks of their life, caused no seroconversion or positive DTH reaction. In a study of DEPTULA (1988) repeated skin testing exerted no effect on the immune status of 25 seronegative cattle.…”

“…A possibility of detecting cattle infected with bovine herpesvirus type 1 (BHV-1) following intradermal injection of inactivated BHV-1 antigen was first demonstrated by DARCEL and DORWARD (1972). Further studies documented a diagnostic value of the intradermal (ID) testing (a delayed-type hypersensitivity test) of cattle infected with BHV-1 STRAUB et al, 1990;WIZIGMANN et al, 1989). Since this test is based on the intradermal administration of the virus antigen, it is essential from a practical point of view to know the effect it exerts on the immune status especially in animals free from BHV-1 infection.…”

An Evaluation of an Intradermal Test for the Diagnosis of Bovine Herpesvirus Type 1 (BHV‐1) Infection in Cattle

“…et al, 1983;STRAUB et al, 1990) a high agreement (94.5 YO) was found between the VN24 and ID results. Moreover ID test compared to VN24 one showed also a high specificity and sensitivity.…”

“…To make the test comparable it is essential to establish a threshold value for the skin positive reactions unequivocally. Such the value was different and rather arbitrary accepted in earlier reports (CORREA-GIR6N et al, 1975;AGUILAR-SETIBN et al, 1983;STRAUB et al, 1990).…”

BHV1 infections: Relevance and spread in Europe

“…Lately an intradermal test has been introduced whereby it is for example possible to differentiate between a passively and an actively acquired immunity [9][10][11].…”