According to Summit Medical Group, the pus in boils is contagious, making it important to cover a boil with a bandage to prevent passing the infection to others. Boils are caused by Staphylococcus bacteria.
To prevent the spread of bacteria, when a person has an active boil infection, he should not share towels and washcloths with others, notes Summit Medical Group. All bandages that come in contact with a boil should be carefully thrown away to prevent contamination of other areas of the skin or other people. Showering using an antibacterial soap can also help decrease the staph bacteria load on the skin and prevent the spread of infection.