Impaired response to killed Newcastle disease vaccine in chicken possessing circulating antibody to chicken Anaemia agent

Abstract

Broiler breeder hens from the same hatch were reared as two separate flocks, one in the field and one in experimental accommodation. Both received the same vaccination programme using the same batches of vaccines. One flock showed serological evidence of infection with chicken anaemia agent starting at 8 weeks, the other starting at 22 weeks old. Newcastle disease mean antibody titres 4 weeks after killed vaccine injected at 18 or 19 weeks old were 4.6 logs lower in the flock showing chicken anaemia agent antibody from 8 weeks old than in the flock seroconverting at 22 weeks. Three other field flocks showing poor responses to killed Newcastle disease vaccines were examined and found to be chicken anaemia agent positive when vaccinated: a further three flocks showing good Newcastle disease antibody responses were shown to be chicken anaemia agent-antibody negative. No difference in response to infectious bronchitis or infectious bursal disease killed vaccines was demonstrable between the two trial flocks. The significance of chicken anaemia agent as a potential immunosuppressive agent for chickens is discussed with special reference to the control of Newcastle disease in laying and breeding hens.

Detection of chicken anaemia virus by DNA hybridization and polymerase chain reaction

“…Advantages of the PCR are its speed (an analysis takes about 5 h for amplification and agarose gel electrophoresis), specificity and sensitivity. Especially, specificity and sensitivity are particularly important for screening of SPF flocks or for testing contaminations of live virus vaccines (Box et al, 1988) to be used in poultry.…”

Immune suppression of commercial broilers in Croatia, Slovenia, and Bosnia and Herzegovina from 1981 to 1991

“…Although IBD virus is known to interact with CAV (Rosenberger & Cloud, 1989), its incidence was not associated with declining HI titres in this instance (Cvelic-Cabrilo et al, 1988). Box et al (1988) also failed to incriminate IBD virus with poor immune responses to ND vaccine. Many other viruses have been shown to have more severe consequences in the presence of concurrent CAV infection (Yuasa et ah, 1979;von Biilow et al, 1986avon Biilow et al, , 1986bEngstrom, 1988;Otaki et al, 1988a).…”

“…Many other viruses have been shown to have more severe consequences in the presence of concurrent CAV infection (Yuasa et ah, 1979;von Biilow et al, 1986avon Biilow et al, , 1986bEngstrom, 1988;Otaki et al, 1988a). Whereas these interactions are poorly understood, there is no question that CAV causes immune suppression and interferes with both cellular (Otaki et al, 1988b) and humoral (Box et al, 1988;Otaki et al, 1988b) immune responses.…”

“…CAV was considered because it had caused problems in Europe in the 1980s, and had been shown to interfere with immune responses to ND vaccine (Box et al, 1988). It could be evaluated by molecular techniques if archival tissues could be found.…”

A micro‐scale serum neutralisation test for the detection and titration of antibodies to chicken anaemia agent ‐ prevalence of antibodies in Danish chickens

“…Evidently the CAA infection causes anaemia and severe immunodepression (Yuasa et al, 1979;Taniguchiefa/., 1982Taniguchiefa/., ,1983Goryoetal, 1985;Bülowera/., 1986a, b;Goryo et al, 1987;Box et al, 1988;Otaki et al, 1988;Goryo et al, 1989). It has also been associated with haemorrhagic syndrome and gangrenous dermatitis (Yuasa et al, 1987;Engström et al, 1988;Vielitz and Landgraf, 1988).…”