In the matter of time all disease will be analyzed and wiped out. We think nature is benign. We mistakenly thought that all agents causing disease would react to our miracle antibiotics. Yet viruses, bacteria, and parasites remain a threat to the survival of mankind without killing the human host. They survive anywhere.
Bacteria are our friends.
Only a few bacteria are harmful. The good bacteria keep the world clean and green. They release nitrogen into plants. Bacteria in our mouth keep harmful bacteria away. Our white cells make macrophages that are suicide cells destroy bad bacteria and then they die.