Over my 18 years of walking caminos, I have been bitten three times, the most recently being this June. I have seen MANY MANY MANY people with awful batches of bites. If you don't react to these bugs, lucky you; if you've never seen anyone with them, lucky you; but if you think they are not a problem on the Camino, you are deluding yourself. These critters cause three main problems -- problems for the people who are bitten and suffer; problems for the Camino chain down the road; and problems for bringing them back home. The latter two are the ones that give me more concern -- I can tolerate the bites, but the thought of spending thousands to get them eradicated from my home is not a pleasant one.
For the first time, this year I had previously sprayed my backpack and sleeping bag with a peremethrin spray, and was surprised to wake up one morning with bites. At the next albergue, I got the "total treatment" -- and had no further incidents. So, of course there are unknowns -- were those really bed bug bites? (several suggested they were probably fleas, but "probably" is not a good enough answer to avoid treamtment, IMO). Was it smart to spray the equipment beforehand since I got bitten anyway?
Just more "known unknowns" to figure out. Buen camino, Laurie