Hi, thanks for using healthcare magic
Hand foot and mouth disease is caused by different viruses. The coxsackie A type 16 is the cause in most cases but there are at least 6 other types of coxsackie that can cause it and also enterovirus
This is why it is possible to be infected more than once. Even though you may have developed immunity to the particular virus that caused the first infection there are other potential viruses that can cause this infection.
It is possible to prevent the spread or to prevent recurrence by washing your hands often with soaps and disinfectants, disinfecting surfaces and reducing any future contact (hugs, kisses sharing utensils) with persons that are infected.
In terms of treatment, it is mainly supportive . This means adequate fluid intake and treating any pain or fever
I hope this helps