[Epidemiology of bovine hypodermyiasis in canton Vaud: comparison of two methods of mapping the infestation with a view to strategic treatment].

The geographic distribution of bovine hypodermyiasis in the canton Vaud/Switzerland has been investigated in two ways: By direct examination of the animals by the livestock officers at the 1993 annual census and by ELISA on bulk milk sampled in January 1994. The efficacy of the two methods is compared and the distribution of hypodermyiasis presented on a map. The serological analyses have revealed a highly satisfactory degree of sensitivity and specificity (92.1% and 98.1%, resp.). The epidemiological interpretation however, is rather difficult, partly because quite often the animals are not infested on their farms but rather while being on alpine pastures. A monitoring of the herds with a view to an efficient control of hypodermyiasis could thus in a first instance be based on the indications provided by the livestock officers, whereas a serological monitoring in a second place would allow to detect the last and remaining foci of infestation.