Performance of clinical signs to detect bluetongue virus serotype 8 outbreaks in cattle and sheep during the 2006-epidemic in The Netherlands.
The performance of clinical signs as a diagnostic test for the detection of BTV-8 outbreaks during the 2006-epidemic in The Netherlands was evaluated by constructing and analysing receiver operating characteristic (ROC) curves. The area under the ROC curve of the BT-associated clinical signs in cattle was 0.77. An optimal efficient test (maximising both sensitivity and specificity) in cattle herds combined a sensitivity (Se) of 67% with a specificity (Sp) of 72%, comprising the following clinical signs: ulcerations and/or erosions of oral mucosa or erosions of lips/crusts in or around nostrils or oedema of the nose or hyperaemic/purple coloration of tongue, tongue protrusion or coronitis or apathy/tiredness or muscle necrosis, stiffness of limbs or loathing or refusal to move, prostration or torticollis or anoestrus. The area under the ROC curve of the BT-associated clinical signs in sheep was 0.81. The optimal efficient test in sheep flocks combined a Se of 76% with a Sp of 72%, comprising the following clinical signs: ulcerations of oral mucosa or serous nasal discharge or erosions/ulceration of tongue mucosa or hypersensitivity of the skin or muscle necrosis, stiffness of limbs or coronitis or grinding of teeth or salivation or weakness/paresis.
Elbers
A R W
AR
Department of Virology, Central Veterinary Institute of Wageningen UR, Lelystad, PO Box 2004, 8203 AA Lelystad, The Netherlands. armin.elbers@wur.nl
Backx
A
A
Ekker
H M
HM
van der Spek
A N
AN
van Rijn
P A
PA
D000818:Animals; D001819:Bluetongue / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D001820:Bluetongue virus / Q000145:classification*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000821:virology; D004196:Disease Outbreaks / Q000662:veterinary*; D009426:Netherlands / Q000453:epidemiology; D011159:Population Surveillance; D012680:Sensitivity and Specificity