Serological survey of bluetongue virus serotype-8 infection in South American camelids in Switzerland (2007-2008).
BACKGROUND
Outbreak of bluetongue virus serotype-8 (BTV-8) infection in domestic ruminants in Northern Europe.


OBJECTIVE
To investigate the South American camelids' (SAC) susceptibility to BTV-8 infection, their role in the epidemiology of the disease, and the use of currently available serological screening tests in SAC in an endemic region.


METHODS
Three hundred and fifty-four unvaccinated and 27 vaccinated SAC (170 llamas, 201 alpacas), ranging in age from 1 month to 17 years between June and August 2008. The SAC originated from 44 herds throughout the country, representing 10% of the Swiss SAC population.


METHODS
Prospective, observational study of a convenience sample of SAC. Serum samples were analyzed with 2 serological screening tests. When results diverged, a 3rd ELISA was carried out for confirmation (ID Screen Bluetongue Competition ELISA kit).


RESULTS
All sera from the 354 unvaccinated animals were negative in the endemic region. Reliable seroconversion was observed after administration of 2 doses of vaccine.


CONCLUSIONS
This study suggests a low susceptibility of SAC to BTV-8 despite the presence of the virus in the cattle and small ruminant population, indicating that SAC do not play a major role in the epidemiology of BTV-8. Furthermore, these results indicate that commercially available serological tests for BTV-8 can be used in SAC.
Zanolari
P
P
Clinic for Ruminants, Vetsuisse Faculty, University of Berne, P.O. Box 8466, Bremgartenstrasse 109a, 3001 Berne, Switzerland. patrik.zanolari@knp.unibe.ch
Chaignat
V
V
Kaufmann
C
C
Mudry
M
M
Griot
C
C
Thuer
B
B
Meylan
M
M
D000818:Animals; D001819:Bluetongue / Q000453:epidemiology / Q000821:virology*; D001820:Bluetongue virus / Q000145:classification* / Q000302:isolation & purification*; D002161:Camelids, New World; D002417:Cattle; D004196:Disease Outbreaks / Q000662:veterinary; D004197:Disease Reservoirs / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay; D013557:Switzerland / Q000453:epidemiology