Respiratory disease (rhinotracheitis) in turkeys in Brittany, France, 1981-1982. I. Field observations and serology.

During the summer of 1981, a respiratory disease epidemic occurred in turkeys in Brittany, France. Since this initial epizootic, which lasted through fall, epizootic waves similar to the initial one have occurred at approximately 6-month intervals, with smaller peaks at 2-month intervals. The epidemiology, clinical signs, and postmortem findings were highly suggestive of an epizootic of chlamydiosis. Serological tests for chlamydia, paramyxoviruses, avian influenza, adenovirus 127, mycoplasma, and Alcaligenes faecalis were conducted. The chlamydia tests were the only ones consistently positive.

[Results of a serological survey made in France (Vendeé region) in domestic ducks]. / Resultats d'une enquete serologique effectuee en France (vendee) Chez le canard a rotir.

The sera of domestic ducks were examined for antibodies to several infectious agents of palmipeds during the winter of 1982 in the abattoirs in la Vendée, an important region of duck production in the West of France. The performance of each batch and their antecedents was also studied. In Barbary ducks and crossbred ducks (from male wild ducks and female domestic ducks), antibodies were found to the virus of egg drop syndrome 16 (EDS 76), to Newcastle disease virus (NDV), to duck hepatitis virus and to chlamydia psittici. In Nantais ducks (resulting from a cross between Khaki Campbell and Pekin ducks), antibodies were detected against EDS 76 virus, duck hepatitis virus and chlamydia. The frequency and levels of antibodies varied between types or strains of ducks. About 50% of the Barbary ducks had high levels of antibodies to EDS 76 virus, whereas 70 to 80% of crossbred and Nantais ducks had these antibodies but at very low levels. Virtually 100% of Barbary ducks had high levels of antibodies against Derzsy's disease virus whereas only 10% of the batches of crossbred ducks had antibodies at varying levels. The proportion of batches with antibodies against NDV was higher in crossbred ducks (25%) than in Barbary ducks (2%) and the titres were low. Antibodies to duck hepatitis virus, when present, were of a high titre irrespective of type or strain of duck. Infection by chlamydia was suspected in 3% of lots of Barbary ducks, in 33% of lots of crossbred ducks, and in 3.7% of lots of Nantais ducks. These findings are discussed and considered in relation to breeding history and performance of the flocks. The EDS 76 virus could in certain circumstances cause weight loss in male Barbary ducks. These epidemiological observations need to be confirmed experimentally.

[Comparison of counterimmunoelectrophoresis with standard serological tests in the diagnosis of ovine brucellosis]. / Comparaison entre électrosynérèse et épreuves sérologiques classiques dans le diagnostic de la brucellose ovine.

Sera from 30 sheep experimentally infected and from 126 others with chronic brucellosis were comparatively studied by serum agglutination (SA), complement fixation (CF), rose bengal (RB), and counter-immunoelectrophoresis (CIEP) test. Standard serological tests, particularly SA and RB, essentially detect antibodies against cell-wall fractions of Brucella (LPS), whereas CIEP responds to intracellular antigens. Antibodies involved in this test appear late but remain a long time in the sera. CIEP is therefore recommended for screening of animals with chronic brucellosis in which SA and often CF and RB tests too negative.

[Immunization of ewes against experimental Brucella melitensis infection: comparison of eleven vaccines]. / Immunisation de la brebis contre l'infection expérimentale à Brucella melitensis: comparison de onze vaccins

A comparative study of 11 antibrucellic vaccines has been carried out in the Limousin region of 360 ewe-lambs divided into groups of 30, a 12th group serving as control. After being vaccinated at 8 months, the ewe-lambs were covered between 9 1/2 and 10 1/2 months, then infected at 11 months with Br. melitensis strain 53 H 38 by instillation of 4 x 10(6) germs on the conjonctiva. Six of these vaccines reduced the number of abortions and the excretion of brucella at parturition: three consisted of an inactivated suspension of a virulent S strain of Br. melitensis in oily adjuvant, another consisted of an inactivated suspension of a modified non-agglutinogenic strain of Br. melitensis also in oily adjuvant, the fifth was prepared from Br. melitensis H 105 and Br. abortus B 112 with saponin and the sixth from a strain of Br. melitensis modified with aluminium hydroxide as adjuvant.