SEROLOGICAL PREVALENCE OF HYPODERMA SPECIES IN CATTLE IN GREAT-BRITAIN (1995 96) AND THE RELATIVE VALUE OF SEROLOGICAL SURVEILLANCE OVER CLINICAL OBSERVATION/

Sera from 100,400 cattle on 2850 farms in England, Scotland and Wales were tested for the presence of antibodies to Hypoderma species betwee n the end of November 1995 and the end of February 1996. Twelve animal s were resampled because the initial results were equivocal but only o ne of them was confirmed as seropositive. This animal was a bull impor ted from Belgium which had been treated with an approved warble fly tr eatment within 24 hours of arrival at its destination in Great Britain , No seropositive animals were confirmed within the native British cat tle population, Statistical analysis of these data indicates that the probable maximum number of infested cattle herds in Great Britain is 1 12, To detect the disease by direct clinical observation would require more than 500 herds to be infested, indicating that the serological t esting of this number of cattle and farms is more than four times as s ensitive as clinical observation for the detection of hypodermosis.