Relative Efficiency of Test Procedures to Detect Lymphoid Leukosis Virus Infection

Abstract

A total of 2544 comparisons were used to study the relative efficiency of various test procedures currently used to detect lymphoid leukosis virus infection in chickens. Meconium, blood, cloacal swabs, and egg albumen were collected from day-old chicks and adult hens from four breeder flocks. The phenotypic mixing was used as the biological assay for infectious virus. The complement fixation test and enzyme-linked immunosorbent assays were used as direct assays for the group-specific antigen of the avian leukosis-sarcoma viruses. Analysis of test results of biological assays has shown that blood from virus-infected chicks was more frequently positive than meconium. Also, direct assay for group-specific antigen was as efficient as the biological assays for detection of positive albumen samples from freshly laid eggs. The rate of false-positive reactors recognized by direct assays was lower in albumen samples than in cloacal swabs collected from hens that produce endogenous virus or group-specific antigen. Data also showed a relatively high concordance, ranging from 71 to 100%, between various assays with test materials from adult hens. Progress in reducing rates of exogenous lymphoid leukosis virus infection can be significant if dams are selected on the basis of any one of the test procedures examined. For complete eradication however, day-old chicks should be selected on the basis of the biological assay of blood of individual chicks reared in small groups.

The use of Elisa for detection of exogenous and endogenous avian leukosis viral antigens in basic breeding flocks

“…In addition, since of the 12 endogenous ALV* eggs (Table 4) only five albumens from the same eggs were gs + , the excretion of endogenous ALV gs-antigens seems to have an intermittent character. Our observations confirm those of Fadly et al (1981) who detected endogenous ALV gs-antigens in albumen samples from both gs+chf 1 " and V-E + phenotype flocks. However, the endogenous ALV gs-antigen levels seem to be below those of exogenous ALV gs-antigens.…”

Practical application of Elisa for detection of vertical transmission of leukosis virus in commercial layer hens

“…Results obtained with the ELISA system in the present studies support the report of Fadly et al (1981) that gs antigen may be present in large amount in vaginal swabs but absent in albumen samples from hens expressing endogenous gs antigen (or virus). The present study also confirms earlier results (Spencer et al, 1976;Payne et al, 1979) on the predictive value of tests on albumens in the detection of congenital transmission of LLV by infected hens.…”

Application of monoclonal antibodies in the dutch avian leukosis control programme

“…Circumstantial evidence for the shedding of gsa of endogenous origin has been described but this usually resulted in relatively low levels of endogenous gsa (Fadly et al, 1981;De Boer et al, 1983). Congenital transmission (via the exogenous route of infection) of complete endogenous ALV, which should give rise to higher titres of endogenous gsa, seems to be restricted by its own gag gene products (Robinson and Eisenman, 1984).…”