Points to keep in mind (re-iterating what others have said):
1. Reptiles can carry salmonella, so can many foods, dogs, cats, etc. Washing of hands is critical to prevent YOU from physically carrying the salmonella bacteria to the baby, no matter what the source.
2. Babies have an immature immune system and so are often more susceptible to infection. Obviously is is best to not have a baby anywhere near a reptile cage, handling equipment, water bowls and the reptiles themselves. Keep the baby away from the pets (this is easy until the baby is a toddler and starts walking, but by then their immune systems are more developed.) The CDC says to age 5. That is very hard to do in a household with a mobile and inquisitive child. A locked room is a good solution. Limited contact with hand washing afterwards.
You do the above, and you will have no problems. I happen to know of one case where a toddler got salmonella from (they think but cannot prove) playing in a room where about 50-plus snakes were in racks. The child was playing on the floor in there and did so routinely. In any case, the child was treated and is just fine. Those people now lock the reptile room door. Easy solution, no more problems, much more reponsible on their part.
-----
Mark