 In 1946, bovine virus diarrhea was discovered, which is still possibly the most common pathogen of cattle throughout the world and in 1957, equine arterivirus was discovered.In the 1950s, improvements in virus isolation and detection methods resulted in the discovery of several important human viruses including varicella zoster virus, the paramyxoviruses, – which include measles virus, and respiratory syncytial virus – and the rhinoviruses that cause the common cold.In the 1960s more viruses were discovered.