I also became an expert on bedbug inspection, eradication and psychological counselling for the afflicted victims when I worked as a hospitalero in Zamora in November. I had worked in Granon in May and treated the albergue over 4 days as part of the SOP. I sprayed Biokill ( a relatively mild pesticide ) over the albergue on day one, on one side of the sleeping mats on day two and then turned them all over, on the new top side on day three and turned them again and mopped over where I sprayed on day two and then repeated the mat turning and mopping one last day. We did not have any cases reported to us although bedbugs are most active at 4 a.m. and the anesthetic/anticoagulent they inject before sucking lasts for about 4 hours so the pilgrims may have been down the road before they felt the effects (and I understand only about half of victims show a reaction at all).
I was quite cocky that we had it solved but a stay as a hospitalero in Zamora was a quite a different story. We only had 31 pilgrims over a half month (less than our daily average in Granon) but fall is a much worse time for bedbugs as they thrive at temperatures between 20 and 30 degrees C (68 F to 86 F for those of you from the one country in the world that likes to hold on to the British Imperial system). Therefore the fall is worse and on the Via de la Plata the pilgrims have few to no options as to where to stay and some albergues are granjas de chinches.
Some people also noted that you can get them in hotels as one bugshocked peregrina was sure of her infestation happened staying with her mother in one in Salamanca. We treated her with a chance to eradicate, an extra day's stay to make sure this happened and a reading of "Ode to a Bedbug" and lots of assurance that it could happen to anyone.
This really turned out to be true when my hospitalera partner got bitten on three successive nights. The first time we were not absolutely sure, the second time we were so we changed her room and treated her abode. However she was bitten in the new room as well.
Research found that they can travel up to 30 m (almost 100 feet) a night and seek us out by looking for our heat and humidity. Bug repellants work less effectively on them so I doubt that using Deet is worth its potential health risk.
This brings me to the most important point. Bedbugs will not kill you. Prolonged exposure to strong pesticides (agricultural workers, etc.) has been linked to Parkinson's disease and cancer. I challenged our supervisor in Granon and raised this as an issue at the Hospitalero Encuentro after I heard that hospitaleros had been instructed to apply it daily there. Marina assured me that Biokill is a mild pesticide (and indeed it is only advertised to be effective for a month compared to what we used in Zamora that said you would be bedbug free for over a year). She also said this was approved for domestic use and the health inspectors required this. Overspraying may also be problematic if you create the situation where the bedbugs develop a tolerance or immuntiy. I understand some researchers are investigating the possibility of using a fungus that is 100% lethal against bedbugs. I hope if used it will not have any negative health effects on humans. By the way bed bugs were largely eliminated from our homes by the application of DDT proving that some cures are worse than the disease.
I know protocols are important but will not keep the albergue bug free of course because the pilgrims kept bringing them through the door in their belongings. However our succcessors in Zamora up to a month later reported that they had not had any new cases. The recommended spraying schedule I have seen is every ten days because this is how long it takes for the eggs to hatch.
Also as adults we can use certain chemicals that do not pass the skin barrier (although we should be using masks and gloves) but children do not have this protection.
There have been some good comments already about looking for the "black pepper" fecal material as well as the different stages. To treat the albergue in Zamora we used pesticide as our ultimate weapon, but also sprayed with alcohol but were somewhat concerned with flamability (where some of our pilgrims believe that smoking in the albergue is their right). We also bought an iron which we left behind both to steam the sleeping bags, beds and mattresses as well as to siron clothes. Heat over 45 degrees C (oh you figure it out in F) is more effective than cold apparently.
Now that I have made you all itchy I will close. I wrote a summary for Canadian hospitaleros that I will get posted on our blog.
http://canadianhospitaleros.blogspot.ca/
