A COMPETITIVE ELISA FOR THE SERODIAGNOSIS OF HYPODERMOSIS

Hypodermosis is a parasitic disease of cattle caused by Hypoderma line atum and H. bovis. It is an important health and welfare problem of in fested cattle and a cause of considerable economic loss. In live anima ls, detection can be either by direct clinical examination of infested cattle and palpation of second and third stage larvae in the back or by the use of serological methods. This paper describes a competitive ELISA for the detection of antibodies to Hypoderma species in cattle s era. It has been validated using a small panel of 40 samples from clin ically positive cattle and 200 samples from clinically negative (unexp osed) cattle from a warble free area. Sensitivity and specificity calc ulated from this panel were 100% and 92% respectively at 2 SD from the mean or 92.5% and 98.5% at 3 SD from the mean. The use of serology an d direct clinical examination of affected cattle, are discussed as met hods for monitoring hypodermosis. The competitive ELISA should prove a useful adjunct to the standard sandwich ELISA, particularly in the re solution of samples which display non-specific binding properties.