Tags

Type your tag names separated by a space and hit enter

Changes in the incidences of the different serovars of Haemophilus paragallinarum in South Africa: a possible explanation for vaccination failures.

Abstract

Infectious coryza remains an important disease in the poultry industry despite the long-term and widespread use of vaccines against its causative agent, Haemophilus paragallinarum, in South Africa. In order to detect antigenic changes between populations of H. paragallinarum isolated before the use of vaccines against infectious coryza in this country, and field isolates obtained after the introduction of infectious coryza vaccines, 106 different NAD-dependent isolates (of which 93 were identified as H. paragallinarum) from 63 different farms, and dating from 1972 to March 1995, were identified by means of rabbit antisera against serogroups A, B and C. Serogroup C isolates show weaker cross-protection, requiring the further subdivision of this serogroup into its four different serovars. The percentages of the different serovars obtained in the 1970s, confirmed previously published data on South African isolates. A tendency towards a decrease in the number of serogroup A and serovar C-2 isolates, and an increase in the percentage of serovar C-3 isolates, was noted among isolates of the 1980s. These changes were markedly enhanced in the isolates obtained from 1990 to March 1995. The percentage of serogroup A isolates decreased significantly from 34% in the 1970s to only 5% in the 1990s, and that of serovar C-2 isolates, from 31-18%, while the abundance of serovar C-3 isolates increased significantly from 31% in the 1970s to 73% in the 1990s. Serogroup B remained more or less constant and never reached more than 10% of the population. These results indicate the need for the incorporation of serovar C-3 in a vaccine for use in South Africa, particularly in those areas of the country from which isolates were collected during this study. Some of the NAD-dependent isolates obtained from poultry in South Africa between 1970 and 1995, were biochemically identified as Pasteurella avium and P. volantium. As H. avium has been subdivided and reclassified into the genus Pasteurella, this represents the first report of the identification of P. avium and P. volantium in South Africa.

Authors+Show Affiliations

,

Department of Poultry Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.

,

Source

MeSH

Agglutination Tests
Animals
Antigens, Bacterial
Chickens
Haemophilus
Haemophilus Infections
Hemagglutination Tests
Incidence
Poultry Diseases
Respiratory Tract Infections
Serotyping
South Africa
Vaccines

Pub Type(s)

Journal Article

Language

eng

PubMed ID

8917859

Citation

Bragg, R R., et al. "Changes in the Incidences of the Different Serovars of Haemophilus Paragallinarum in South Africa: a Possible Explanation for Vaccination Failures." The Onderstepoort Journal of Veterinary Research, vol. 63, no. 3, 1996, pp. 217-26.
Bragg RR, Coetzee L, Verschoor JA. Changes in the incidences of the different serovars of Haemophilus paragallinarum in South Africa: a possible explanation for vaccination failures. Onderstepoort J Vet Res. 1996;63(3):217-26.
Bragg, R. R., Coetzee, L., & Verschoor, J. A. (1996). Changes in the incidences of the different serovars of Haemophilus paragallinarum in South Africa: a possible explanation for vaccination failures. The Onderstepoort Journal of Veterinary Research, 63(3), pp. 217-26.
Bragg RR, Coetzee L, Verschoor JA. Changes in the Incidences of the Different Serovars of Haemophilus Paragallinarum in South Africa: a Possible Explanation for Vaccination Failures. Onderstepoort J Vet Res. 1996;63(3):217-26. PubMed PMID: 8917859.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Changes in the incidences of the different serovars of Haemophilus paragallinarum in South Africa: a possible explanation for vaccination failures. AU - Bragg,R R, AU - Coetzee,L, AU - Verschoor,J A, PY - 1996/9/1/pubmed PY - 1996/9/1/medline PY - 1996/9/1/entrez SP - 217 EP - 26 JF - The Onderstepoort journal of veterinary research JO - Onderstepoort J. Vet. Res. VL - 63 IS - 3 N2 - Infectious coryza remains an important disease in the poultry industry despite the long-term and widespread use of vaccines against its causative agent, Haemophilus paragallinarum, in South Africa. In order to detect antigenic changes between populations of H. paragallinarum isolated before the use of vaccines against infectious coryza in this country, and field isolates obtained after the introduction of infectious coryza vaccines, 106 different NAD-dependent isolates (of which 93 were identified as H. paragallinarum) from 63 different farms, and dating from 1972 to March 1995, were identified by means of rabbit antisera against serogroups A, B and C. Serogroup C isolates show weaker cross-protection, requiring the further subdivision of this serogroup into its four different serovars. The percentages of the different serovars obtained in the 1970s, confirmed previously published data on South African isolates. A tendency towards a decrease in the number of serogroup A and serovar C-2 isolates, and an increase in the percentage of serovar C-3 isolates, was noted among isolates of the 1980s. These changes were markedly enhanced in the isolates obtained from 1990 to March 1995. The percentage of serogroup A isolates decreased significantly from 34% in the 1970s to only 5% in the 1990s, and that of serovar C-2 isolates, from 31-18%, while the abundance of serovar C-3 isolates increased significantly from 31% in the 1970s to 73% in the 1990s. Serogroup B remained more or less constant and never reached more than 10% of the population. These results indicate the need for the incorporation of serovar C-3 in a vaccine for use in South Africa, particularly in those areas of the country from which isolates were collected during this study. Some of the NAD-dependent isolates obtained from poultry in South Africa between 1970 and 1995, were biochemically identified as Pasteurella avium and P. volantium. As H. avium has been subdivided and reclassified into the genus Pasteurella, this represents the first report of the identification of P. avium and P. volantium in South Africa. SN - 0030-2465 UR - https://www.unboundmedicine.com/medline/citation/8917859/Changes_in_the_incidences_of_the_different_serovars_of_Haemophilus_paragallinarum_in_South_Africa:_a_possible_explanation_for_vaccination_failures_ L2 - https://medlineplus.gov/haemophilusinfections.html DB - PRIME DP - Unbound Medicine ER -