species barrier

plural species barriers

1. biologyThe inability of a disease to be transmitted from one species to a different one.

   The people had died because they ate meat from infected cows. A species barrier had crumbled.

   2003 June 3, Sandra Blakeslee, “Mad Cows, Sane Cats: Making Sense of the 'Species Barrier'”, in The New York Times, →ISSN

   1 more example

   The species barrier often is not an absolute barrier and refers to the difficulties in the transfer from one species to the next.

   2004, W. Michael Scheld et al., editors, Infections of the Central Nervous System, Lippincott Williams & Wilkins, →ISBN, page 261