As the other answers say, chemtrails is a conspiracy theory. Contrails are real. Airplanes contrails are like high cirrus - depending on the weather conditions they can persist for long periods of time. I think it’s not surprising that some Morgellons suffers might look everywhere for a solution as the “party line” is that it is a delusion. When you are suffering severe pain, as they say they do, and you have no previous history of mental illness or delusions, it’s going to be very hard to accept a diagnosis of delusion. But Morgellons may be a real disease. The CDC definitely did not “close the book” and the few remaining researchers in this topic have all converged on a new hypothesis which wasn’t around at the time of the survey. This is the hypothesis that it is related to digital dermatitis, a disease of cattle. If so then it is caused by spirochetes, similar causal agent to Lyme disease though it is a different disease. You can protect yourself from it in that case by following the same precautions as for Lyme disease of removing ticks and going to the doctor right away if you get a circular rash. For more on this see my answer to How do I get infected with Morgellons disease?