I did a pile of research on the Camino before leaving. One of the recurring themes was concerns over bed bugs, a topic that scares away some people from even considering doing the walk. For me though, it wasn't really a concern, and in fact I had a feeling that the whole issue was likely overblown. Guess in the end I was wrong.

Over the first two and a bit weeks of the walk there were no signs of bedbugs, and hadn't really heard any stories of them along the trail. But just past the halfway point the first rumours surfaced. Within a day or so Cheryl related a conversation she had with one of the men that stayed with us at our hostel in Angostura, who had been bitten, and in fact had seen one drop out of his knapsack when taking out his sleeping bag. Unfortunately he had done nothing about it which becomes part of the way these things spread. Then the bites started showing up on Judy, and shortly thereafter on Mary Lou, with swelling and water blisters to the point that they had to see the doctor in Leon to get medicated ointment. Emails with Will, who was a couple of days behind us told of albergues being temporarily closed because of bedbugs, and tales of numerous people being bitten. It was like being chased by a big swarm of bees.
The biggest risk from being bitten by bed bugs is the irritation of the skin, of just plain being physced out at the thought of being bitten, and losing sleep because of it. You usually can't see the bites until a day or more after they suck your blood, if at all, since some people never react to being bitten. In some cases, people may develop blisters or even hives as a result of these bites. So it was for Mary Lou and Judy, and each morning I got out a jack knife, peroxide and bandaids to take care of MLs bites. Have to say, for all the discomfort they suffered, the girls did a yeoman job of fighting through, and were not the least bit squeamish about going to sleep. Now here is the odd part, neither Nick or I had a single bite. Go figure.
Having said that, don't let this scare you away from walking the Camino. If you do, then the terrorists have won. Though there were quite a few stories of the critters, the percentage of people that were bitten was not that high. From what I could tell this was an unusual year for them, and most people who have walked it will tell you they never saw them. If you do find them, simply wash everything in hot water and your good to go. People who come from anywhere outside a big city, likely get more black fly and mosquito bites sitting out the porch at twilight. Says the guy who didn't get a single bite.