One of the core issues in managing the human internal ecosystem with electromagnetic frequencies is tipping the balance in favor of more harmless organisms, i.e. find the bad guys and shoot them without harming the good citizens.
Professor Ewald articulates this as a public health strategy in the PBS series on Evolution:
Q: How does understanding the evolution of virulence help us to manage infectious disease?
A: For most of the last two centuries people have been using interventions to knock down infectious diseases as much as possible. The idea is that we’re going to use weapons like vaccines and antibiotics or hygienic interventions to reduce the frequency of infection as much as possible.
My point is that there’s another way of controlling these disease organisms. Instead of using these weapons — antibiotics and vaccines and hygiene improvements — as a way of knocking down the organism, we can use those interventions to control the evolution of the organisms instead of getting the organisms evolving around our interventions. We can get the organisms to evolve to be less harmful than they have been in the past. Essentially, what I’m saying is we can use interventions like vaccines or like hygienic improvements to domesticate these organisms.
That argument may seem a little bit surprising, but we’ve already domesticated organisms in many ways. One of the most obvious ways is when we make live vaccines in the laboratory. We’re actually taking harmful organisms [and] changing the course of their evolution, making them evolve to be mild enough that we can then introduce them into people as a vaccine.
Professor Ewald comments on trying to avoid nosocomial infections in an Omni interview:
Omni: Can we avoid being infected at the hospital?
Ewald: Unfortunately, we’re at the mercy of the hospital. When my daughter was born, in a good hospital in Washington State, my wife and I were appalled that a nurse stuck her finger in the baby’s mouth to quiet her. We tried to explain why we didn’t think it was a good idea, and she was offended. When we talked to the pediatrician, he got indignant and said, “I do it all the time myself.”