Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "Disease is not contagious, and evil omens are not permissible."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14232
Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Disease is not contagious, the owl is not an evil omen, and the month of Safar is not an evil omen either." Then a Bedouin stood up and said: O Messenger of Allah (peace and blessings be upon him)! Camels are in the sand like gazelles, then a camel with mange is brought among them and they all become mangy. The Messenger of Allah (peace and blessings be upon him) asked: "Then who gave the mange to the first one?"
(b) In the narration of Yunus: The Messenger of Allah (peace and blessings be upon him) said: "Disease is not contagious, the month of Safar is not an evil omen, and no owl is an evil omen." Then a Bedouin said: Then what about the camels that are healthy like gazelles, and a camel with mange comes among them and makes them mangy too? He (peace and blessings be upon him) asked: "Then who gave the mange to the first one?"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14233