Hi - you will have a lovely time.
There are three types of bed bug people:
I don't know anything about them.
I don't care.
No way am I getting them.
Most people will not get them. But let me tell you they are there. People in category two will say pffft and tell you you are paranoid/OCD/can't be helped. my advice is steer clear of them. They are the people most likely to have them, not know, not care; and pass them all along the route and to their fellow pilgrims. Would you be so blasé about STI's? I doubt it!
I did not get bed bugs on the Frances 2 years ago. It I saw them, I saw evidence of them, I met people covered in. It's and I met people who had met people who had been to hospital they were so badly bitten.
The root cause of bed bugs is poor hygiene. By pilgrims, but most importantly by albergues.
Understand that albergue owners, workers and occasionally merely overseers, come in all shapes and sizes. Some are haphazard hippy types, some are entrepreneurs with high standards, some are locals who love the camino and some are just lazy/blaze people employed by the local authority, or setting up their own little outpost against the iniquities of The modern world.
Also understand you can get bed bugs in the cleanest seeming places and up to date hotels.
Bearing all that in mind, here is my advice:
1. Do not get bed bugs.
2. If you get them, nuke everything and take practically forensic measures not to take them home. As in strip naked at the door and bad all your clothes and gear in bin bags and zip tie them and leave them in a shed until you decide on a plan to deal with your stuff once you are home again and you are sure you are not carrying them.
3. Once a place gets bed bugs, they are unlikely to get clear of them ever again completely. That includes your home.
4. Avoid anyone with bed bugs. If they talk about it, if they have bites on their face, arms, legs.
5. Avoid places run by hippies. Aside from an aversion to chemicals hippy people usually have an approach to infection control which would not be sanctioned by anyone in the medical profession. They also generally have a more laid back approach to life.
6. In tandem with the above, wood, is never a good sign. If you come to a place and they want to give you fresh picked herbal tea and they are really nice and laid back and dressed in tie dye and the decor is all wooden and old looking and inviting, be extra vigilant.
7. Concrete and metal and newness of building is perfect. Metal bunk beds with new plastic covered mattresses and disposable pillow covers issued at the reception are heaven. These materials are not Happy homes for bugs and are easily kept clean. Metal springs under the bed are better than wooden slats.
8. Before you unpack or get on your bed inspect it. If the sheets look like they are not cleanly laundered - bail and find somewhere else. I saw one place where in the morning the hospitaliero went round brushing them sheets off. That was it. Look for stray hairs that indicate a previous occupant, stains and crumpled sheets.
9. Inspect the sheet, pillow, seams of both, under mattress, bed soars below you, bed slats about you (bunks), under the bed, and a quick look at neighbouring beds. Especially look in and around the seams. Unzip mattress covers if necessary. Pay especial attention to books and crannies. You are looking for: black mould, clear tiny beasties, brown small beasties. The mould is their shit. If they are there it's the first think you will likely see and think it is just dirt or mould. If you see any of these things, leave.
Find somewhere else to stay.
10.thats it. Other will tell you better how to get rid of them but in my view not getting them is the best.
11. Once you find one you will never feel like an idiot for looking again. Look out for your fellow pilgrims and they will thank you. Also it will help you in case the next bunk is a problem.
Anecdotes:
Stayed In a wooden place with several small dorms. My room is as OK. Someone staying in another room got them.
Went to a wooden place with voluntary hippies etc seems nice, plastic mattresses. Checked the bed way up in the corner, saw mould, found a bug in Sean of mattress zipper, found a dead bug on another mattress. Demanded refund- left with my friends. Told a Japanese party - they blew it off like it was no concern. Went to a municipal concrete and metal place and felt less soul, but clean and happy.
Went to a municipal place. Wooden. Climbed on bed shattered and noticed a hair on pillow. Then stains. Then noticed stains were not actually stains but crusts of something. Got off bed, inspected, found dead bug in mattress seam as well as lots of tiny clear bugs alive and well. Left with others. Demanded refund. Got it afterargument involving the word Internet.
Met guy in santiago whole face covered in bites.
Knew of a girl who had to tumble dry everything several times.
Met a guy who went to hospital due to allergic reaction to bites.
Know a girl who got bugs in her hours (not camino related) and has had pest control in several times.
If you check where you sleep you will not have a problem. It is no different than looking at the toilet seat before you sit down!
So don't let me put you off!
You will have an amazing camino and this is no different than all the prep you will do to make sure you don't get too many blisters. Buen Camino amiga!