Illness associated with paramyxo-like virus infection in a zoologic collection of snakes.

Of 438 snakes in a zoologic collection, 35 died during a 3-month period; all were members of the family Viperidae. Clinical signs consisted of gaping of the mouth followed within 1 day by convulsions. All necropsied animals had a mucoid exudate throughout the respiratory tract. Histologic evaluation of lung revealed evidence of interstitial pneumonia, with occasional eosinophilic intracytoplasmic inclusions in epithelial cells. A paramyxo-like virus, isolated in viper heart cells from lung tissue, was observed by electron microscopy to be budding from cell membranes. The virus hemagglutinated chicken red blood cells at 5 C, and antibody titers were assayed by hemagglutination inhibition. In a random survey of 22 snakes from the zoologic collection, antibody titers to the virus ranged from 1/20 to 1/2,560.