1. Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; 1 Shields Avenue Davis CA 95616 USA
2. Faculty of Medical Sciences; School of Veterinary Medicine; University of the West Indies; Champs Fleur Trinidad and Tobago
3. California Animal Health and Food Safety Laboratory; Davis CA 95616 USA
4. Veterinary Diagnostic Laboratory; Ministry of Agriculture; Lands and Marine Resources; Champs Fleur Trinidad and Tobago