Swine vesicular disease, studies on pathogenesis, diagnosis, and epizootiology: a review.

Swine vesicular disease (SVD) is a contagious viral disease of swine. It causes vesicular lesions indistinguishable from those observed of foot-and-mouth disease. Infection with SVD virus (SVDV) can lead to viraemia within 1 day and can produce clinical signs 2 days after a pig has come into contact with infected pigs or a virus-contaminated environment. Virus can be detected 3.5 hours after infection using immunohistochemistry. In these in vitro studies, this technique was superior to in-situ hybridization. In SVDV-infected tissues, however, more infected cells were positive using in-situ hybridization, and these were already seen 4.5 hours after infection. For serological diagnosis of SVD several new enzyme-linked immunosorbent assays (ELISA's) have been developed. The newest ELISAs, based on monoclonal antibodies, are superior to the previous tests. The new tests produce fewer less false-negative results and enable large-scale serological screening. In screening programmes a small percentage of false positive reactors have been detected. The cause of these false-positive reactions has not been identified, though infections with human Coxsackie B5 virus can be excluded.

Likelihood of introducing selected exotic diseases to domestic swine in the continental United States of America through uncooked swill.

To help policy makers determine the need for current regulations (which require cooking of swill prior to feeding to swine), an assessment of the likelihood of exposing domestic swine in the continental United States of America (USA) to selected foreign animal disease agents by feeding uncooked swill was carried out. The hazard was assumed to originate from contraband food items entering the USA and subsequently being discarded in household waste. Such food waste may be collected by licensed waste feeders and fed to swine. This study showed that, of the four diseases studied, the probability of exposure was highest for the classical swine fever (hog cholera) virus. The median annual likelihood of one or more contaminated loads of swill being fed to swine in the continental USA was estimated as follows: classical swine fever virus: 0.063, foot and mouth disease virus: 0.043, swine vesicular disease virus: 0.005, African swine fever virus: 0.005.