Does the infestation with Morgellons only involve children or are adults prone too?

This is being targeted at children more than adults, and that is in keeping with the idea of undercutting humanity. Children are the hope. They are also the beings with greatest personal reach intuitively, and are the future leaders and productive citizens and have the most energy and the freshest outlook, so they are targeted because they are by definition higher risk to the Extraterrestrial Alliance than the adult population which, by and large, is being subjugated quite nicely with mind control manipulation to keep people largely complacent about deep issues and venting their frustrations and anger at the distractions provided by the Cabal in keeping the world always off-balance and dysfunctional.