Instructions about building the tabernacle in Exodus are insufficient to actually constructing a tabernacle. It required more information that God had specifically given the builders He had chosen. In the same way, it is unlikely that Leviticus 13-15 was intended to serve as a medical textbook on infectious diseases or hygiene. Rather, it gave the people of Israel a bit of insight as to what they should be looking for regarding their health, and what the priest (who served as a physician) was looking for when he examined them.
What shall we make of all these instructions?
At least the following is true: God cares about our health. He cares about cleanliness, and He holds us responsible for paying attention to both. We are not only responsible to God, but also responsible to the community in which we live. Uncleanness, and sickness, are sometimes unavoidable, but we are still responsible. Separation from the community of faith means separation from God. It’s serious business. We know a lot more about the pathology of disease than they did in the ancient world. Those laws were given based on what they could know, and treated the same way. But the point remains the same: there is a human responsibility for health. God ends the section by saying to the priests: “You must keep the Israelites separate from things that make them unclean, so they will not die in their uncleanness for defiling my dwelling place.”
God is among us. He holds us accountable for staying healthy, and keeping one another healthy.