In the Old Testament, God gave the Israelites laws regarding food and sanitation.  One example is, "Meat that touches anything ceremonially unclean must not be eaten; it must be burned up" Leviticus 7:19 (NIV). Another example is:

Of the animals that move along the ground, these are unclean for you: the weasel, the rat, any kind of great lizard, the gecko, the monitor lizard, the wall lizard, the skink and the chameleon. Of all those that move along the ground, these are unclean for you. Whoever touches them when they are dead will be unclean till evening. When one of them dies and falls on something, that article, whatever its use, will be unclean, whether it is made of wood, cloth, hide or sackcloth. Put it in water; it will be unclean till evening, and then it will be clean.  If one of them falls into a clay pot, everything in it will be unclean, and you must break the pot. Any food you are allowed to eat that has come into contact with water from any such pot is unclean, and any liquid that is drunk from such a pot is unclean. Anything that one of their carcasses falls on becomes unclean; an oven or cooking pot must be broken up. They are unclean, and you are to regard them as unclean. A spring, however, or a cistern for collecting water remains clean, but anyone who touches one of these carcasses is unclean. If a carcass falls on any seeds that are to be planted, they remain clean. But if water has been put on the seed and a carcass falls on it, it is unclean for you. Leviticus 11:29-38 (NIV)

• Do you see these laws as being excessive or beneficial? Why?
• How might God have been seeking to protect his people from the effects of microorganisms through these laws?
• What further microorganism "controls" might have been helpful and accessible to the Israelites?