Its really important that you keep the baby's environment as free from bacteria as possible. So you always wanna have sanitizer and soap on hand. And really wash your hands with soap or sanitizer every time you get near your baby. If they are sucking on pacifiers or bottles you really wanna sterilize those bottles or pacifiers, or any toys they may be chewing on. You can do this with a sterilizer or a simple pot of water and stove. You also wanna clean your babies' environment if there are any pets or siblings running around the house. There are many products on the market that are free of harmful toxins and are completely safe to spray on toys, on high chairs. Anything your baby touches, you'll wanna clean. And if the friend is over or a sibiling's there, they are touching their mouth and are putting it on the baby's toys; the baby touches that and put it in their mouth, you're gonna spread bacteria. So its very important to wash their pacifiers often, perhaps once a day. Launder their sheets often, launder their blankets if you are taking the blanket out and really try to create a bacteria free environment as much as possible for your child. Exposure to bacteria is actually good for your child in small amounts but too many germs will only make your child sick. So simple cleaning and sterilizing will easily keep your environment very healthy.