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APPENDIX 4 |
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Ground Hornbill Vaccination Trial
by Dr Gabby Drake
Background
Status is vulnerable in S Africa ~1500 Southern Ground Hornbills in the wild in Southern Africa Est. 70% of habitat is gone Kruger and surrounding parks are their stronghold, extinct from much of their range Threatened by habitat loss, nest site destruction, poisoning, shooting, trade and use in traditional medicine
Hornbill Biology
Lifespan of 40-50 years Live in groups of 2-10, with only 1 breeding female Produce 1-3 eggs in the wild in the spring Breeding success of 1 chick raised to adult every 9 years! So, long lived, slow reproducing, every bird counts!
Madikwe 2006
In situ conservation Madikwe juveniles died of ND in 2006 Clinical signs included, anorexia, vomiting, depression and sudden death Female died after 48 hours illness, the male was found dead 15 days later Post Mortem confirmed Newcastle Disease
Newcastle Disease
Caused by a virus: paramyxovirus -1 Quite hardy, airbourne transmission, contact to sick birds, transmission by fomites Known to cause disease in 236 species of bird of 27/50 orders Notifiable disease widespread in wild birds in S Africa Quickly fatal in susceptible birds Eg Chickens
Vaccination
Giving all or part or a disease organism to a healthy individual to stimulate a protective immune response (antibodies)
Live attenuated best immunity, but risky as will multiply in host and could cause disease! Killed/Inactivated safer as no multiplication in host, but less immunity created
Health Exams on arrival, bloods, CBC, biochemistry, xrays, faecal examination Day 0: Blood sample for antibody titre & primer vaccine (Ulster, Deltammune) intraoccular Day 21: Inactivated Ostrich vaccine (Struvac, Deltammune) Subcutaneous Day 49: Blood sample for antibody titre
Possible Outcomes
1. No effect on the Hornbills 2. Clinical disease in the Hornbills 3. Acquired immunity to Newcastle Disease in the Hornbills
Results
Trial MALE: Pre-vac titre= 0 Post-vac titre= 8 Trial FEMALE: Pre-vac titre= 0 Post-vac titre= 9
Hugo, Priscilla, Tsuwane, Marilyn and Derek all titres= 0 (not exposed)
Follow Up
Blood sample these birds every 3 months this will assess how long immunity lasts from this vaccination protocol If immunity decreases quickly, consider booster vaccination Test exposure is not an option as the disease is potentially fatal, and these are endangered birds
Future
Run the same trial on Hornbill chicks Potentially vaccinate all pre-release birds and at risk birds in Zoos/Private collections Use a similar protocol for other at risk exotic species
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