| mystery swine disease in the netherlands: the isolation of lelystad virus. | in early 1991, the dutch pig-industry was struck by the so-called mystery swine disease. large-scale laboratory investigations were undertaken to search for the etiological agent. we focused on isolating viruses and mycoplasmas, and we tested paired sera of affected sows for antibodies against ten known pig viruses. the mycoplasmas m. hyosynoviae, m. hyopneumoniae, and acholeplasma laidlawii, and the viruses encephalomyocarditis virus and porcine enterovirus types 2 and 7 were isolated from indi ... | 1991 | 1835211 |