title: Variation among New and Old World arenaviruses.
mesh_terms: D000349:Africa; D000818:Animals; D001116:Arenaviridae / Q000276:immunology / Q000648:ultrastructure; D001117:Arenaviridae Infections / Q000635:transmission / Q000662:veterinary; D006801:Humans; D008854:Microscopy, Electron; D009500:Neutralization Tests; D013020:South America