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

Abstract

A continuous decline in immune responses to Newcastle disease (ND) vaccine was observed in commercial broiler flocks in Croatia, Slovenia, and Bosnia and Herzegovina beginning in 1982. Floating mean haemagglutination inhibition (HI) titres declined from log(2) 4 in 1983 to a low of log(2) 2.4 in 1986, then were log(2) 2.9 in 1990. Several causes of the decline were discounted, leaving mycotoxins in feed and infection with chicken anaemia virus (CAV) as the two most likely causes. Mycotoxins in feed could not be evaluated retrospectively, but archival tissues were available from Croatia and Slovenia. Tissue sections were examined by in situ hybridization for CAV. Whereas only one chicken from early in the decade was infected, all but one of the chickens from late in the decade were. The increase in CAV detection correlated inversely with ND HI titres. Whereas this correlation does not establish cause and effect, CAV cannot be eliminated as a contributory cause of immune suppression.

Interactions ofPlasmodium juxtanucleareand chicken anaemia virus: establishing a model

“…Thus, the P. juxtanucleare –chicken host model could provide substantial information, allowing measurement of the impacts caused by different pathogens during chronic malarial infection. In this context, coinfection with this plasmodia species and the chicken anaemia virus (CAV), a widespread infection (Nogueira et al 2007; Craig et al 2009; Eltahir et al 2011; Snoeck et al 2012; Marin et al 2013) that is potentially immunosuppressive (Ragland et al 1998; Kuscu and Gurel, 2008; Schat, 2009; Haridy et al 2012; Gallardo et al 2012), could be considered a useful model in determining possible synergistic or antagonistic effects.…”

Epidemiology of viral components causing respiratory problems in broilers in six Egyptian Governorates

“…In addition to, immune suppression in chickens is a frequent problem in poultry production (Jackwood, 1991). It may be caused by many viruses as lymphoid leucosis, IBD, Infectious anemia and Marek's or may be caused by mycotoxin that lead to decline in the immune response to the vaccines and rendered these birds highly susceptible to infection as mentioned by Ragland et al (1998).…”