1. What is infant thrush? Infant thrush, also known as hand, foot and mouth disease, is an infectious disease caused by the coxsackie virus. The disease mainly affects infants and young children, and is characterized by blisters and ulcers in the mouth, hands and feet, accompanied by symptoms such as fever and loss of appetite. The main routes of transmission of the disease are droplet transmission and contact transmission. 2. Causes of infant thrush 1. Coxsackie virus infection: The disease is caused by the Coxsackie virus and is mainly spread through droplets and contact. 2.