title: A comparison of a blocking ELISA and a haemagglutination inhibition assay for the detection of antibodies to Avibacterium (Haemophilus) paragallinarum in sera from artificially infected chickens.
abstract: The ability of blocking ELISAs and haemagglutination-inhibition (HI) tests to detect antibodies in sera from chickens challenged with either Avibacterium (Haemophilus) paragallinarum isolate Hp8 (serovar A) or H668 (serovar C) was compared. Serum samples were examined weekly over the 9 weeks following infection. The results showed that the positive rate of serovar A specific antibody in the B-ELISA remained at 100% from the second week to the ninth week. In chickens given the serovar C challenge, the highest positive rate of serovar C specific antibody in the B-ELISA appeared at the seventh week (60% positive) and was then followed by a rapid decrease. The B-ELISA gave significantly more positives at weeks 2, 3, 7, 8 and 9 post-infection for serovar A and at week 7 post-infection for serovar C. In qualitative terms, for both serovar A and serovar C infections, the HI tests gave a lower percentage of positive sera at all time points except at 9 weeks post-infection with serovar C. The highest positive rate for serovar A HI antibodies was 70% of sera at the fourth and fifth weeks post-infection. The highest rate of serovar C HI antibodies was 20% at the fifth and sixth weeks post-infection. The results have provided further evidence of the suitability of the serovar A and C B-ELISAs for the diagnosis of infectious coryza.
authors.affiliation: Institute for Animal Husbandry and Veterinary Science, Beijing Academy of Agriculture and Forestry Science, Haidian, Beijing, People's Republic of China.
authors.forename: H
authors.initials: H
authors.lastname: Sun
authors.forename: D
authors.initials: D
authors.lastname: Miao
authors.forename: P
authors.initials: P
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Gong
authors.forename: P J
authors.initials: PJ
authors.lastname: Blackall
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis* / Q000097:blood; D000918:Antibody Specificity; D002645:Chickens; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006192:Haemophilus Infections / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary; D044134:Haemophilus paragallinarum / Q000145:classification / Q000276:immunology*; D006385:Hemagglutination Inhibition Tests / Q000379:methods*; D011201:Poultry Diseases / Q000175:diagnosis / Q000276:immunology; D012703:Serotyping; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial