Leonardo da Vinci made immense contributions to medicine and science during the Renaissance period. He revolutionized the fields of anatomy, medical applications, surgery and infectious disease control through his medical research. Da Vinci was the first to recognize that diseases often spread through direct contact with infected individuals, animals or parasites. He established early practices of hygiene like using soap, keeping environments clean and safely disposing of waste, which reduced disease in Milan. While renowned for his artwork, da Vinci's work in sanitation and hygiene helped establish modern practices of cleanliness and infection control in medicine.