Definitely yes with an indwelling catheter, and the chance of infection(s) are directly proportional to length of time that it dwells
Lina needs to be able to see what Mr. Brown is reading aloud. The more senses used to learn, the better the outcome. The younger the child, the more crucial it is to integrate the senses in order to develop the "whole" brain.
Sounds like Sergio might be suffering from a fungal infection.