Mention the word bedbugs to Carolyn Lloyd and, as with many in the hotel trade, you will almost hear the shiver down the phoneline.
About four years ago Lloyd, now general manager of the 48-bedroom Hotel Alias Kandinsky in Cheltenham, was working at an upmarket hotel in the Midlands which suffered what was classed as a "mild infestation" of bedbugs.
"We were absolutely devastated, and the housekeeper, who was proud of her high standards, was distraught - but you have to remember it is not the fault of the hotel that you sometimes get them," she recalls.
"We found bugs in one room and had to do the rooms either side. It probably cost us about £2,500, before the cost of four days' lost revenue.
"We had to get a 40ft container and put everything from the rooms in there, fumigate them, leave them for 48 hours and then put it all back together - which is fairly standard," she adds.
Bedbugs are probably one of the most unpleasant occupational hazards of working in the hotel trade and, according to pest control experts, they're getting worse.
An infestation does not only have a severe financial and time cost but can be hugely embarrassing for a hotel's reputation, as the five-star De Vere Grand in Brighton found last month.
The 200-bedroom hotel made headlines when an attack of the minute pests was reported at the height of the Labour Party conference, although De Vere insisted it was an isolated incident and had been quickly dealt with.
"We are finding, particularly in many city centre hotels, that there has been a big resurgence in bedbugs in the past two years," says Elaine Quinn, head of corporate account development at pest-control firm Ecolab.
"They tend to go in cycles. There was a big problem back in 1999-2000, for instance. In the past 15-18 months it has been a topic that a lot of hotel managers have been talking about," she adds.
Although the British Hospitality Association and chains such as Hilton say they have seen no increase of late, research last year by the nstitute of Biology found there had been an unexpected rise in reports of infestations in the UK, USA and other developed countries.
The institute also warned that the bugs could have developed resistance to some pesticides.
In 2002, pest-control firm Terminix said the number of treatments it had carried out had shot up by 37%, with the vast majority of treatments being for hotels.
Hotel chains, perhaps unsurprisingly, are often reticent to talk about such a sensitive issue. De Vere, stung by the publicity over the Brighton incident, came back this time with a very firm "no comment".
InterContinental stressed that it had "very rigorous" housekeeping standards. "We carry out regular internal and external quality evaluation audits. Internal quality evaluations are carried out by a member of hotel management," said a spokeswoman.
"An external quality evaluator will also call in to a property unannounced to conduct a full quality evaluation," she added.
Hilton, which uses Rentokil for its pest control, said it was something about which staff and management were constantly encouraged to be vigilant.
"There is no way to identify when or where they will arrive. You could treat it one day and they could be back the next," said a spokeswoman.
"We have an extensive action plan with Rentokil and do not just treat one room but the ones on either side as well. We keep in constant touch with Rentokil and make sure our employees and managers keep on top of it," she added.
The big difficulty, admits Quinn, is that in an age of global and frequent corporate travel, where people may be staying in three different hotels a week, it is almost impossible to keep completely ahead of the problem.
"It is a lot to do with international travel and with people going from hotel to hotel. You often get pockets or clusters around airport conurbations," says Quinn.
The bugs spread fiendishly easily, too. They can be carried in the luggage or clothes of guests - even something as small as a trouser cuff - and they can be spread when linen or furnishings are moved, through careless cleaning, and even through ducts, pipes and heating systems.
Ecolab has developed a heat-treatment process - the Ecolab Thermal Heat Treatment System - that, it says, can return a room to use by the following day, rather than having to wait three or four days or longer with insecticides.
The treatment involves sheeting up the bed, linen and other furniture in a room and heating it up to 52°C to kill the little critters. The heat is monitored using sensors and a computer.
The process is similar to a treatment developed by pest-control firm Allergan, which seals a room in a "thermal envelope" and heats beds and furnishings to 100°C to kill off any bugs.
Ecolab also holds regular training and education sessions with housekeepers and cleaning staff to keep workers familiar with the warning signs that bedbugs have arrived - and to drive home the message that they need to be vigilant and inspect rooms regularly.
Staff, argue both Quinn and Lloyd, should be checking rooms on a daily basis for telltale signs on the sheets, mattresses, headboards - around the buttons is a common place - and pillows, and behind mirrors, loose wallpaper and pictures.
The blood spots, says Lloyd, are minute and often look black.
"It can be a very expensive business, but you do have to do it properly. You cannot afford to scrimp," she warns.
"If you are tempted to spray just one room, they can still lie dormant for quite a time. At one hotel we made the mistake of just having the room sprayed. But they reappeared nine months later and then nine months again after that. It was two-and-a-half years before we got rid of the problem," she recalls.
Sometimes, drastic measures are the only way to deal with an infestation.
"You should take the sockets off the walls and take up the carpets and skirting boards. The room needs to be stripped back to the basics," Lloyd advises.
"All the furnishings, of course, need to be done, but also the vacuum cleaner - which people often forget - and all the clothes of the people who have been doing the fumigating.
"I heard of one hotel where they ended up having to deal with them in 40 rooms, so it is very important that you stop them spreading," she adds.
The vast majority of hoteliers are vigilant, because it is clearly in their interest to be so, argues John Dyson, food and technical affairs adviser at the British Hospitality Association.
"Hoteliers are aware of it. If you get them, it is expensive, but they are simply one of the hazards of this business," he stresses.
Good training in how to spot them is absolutely key, and hotels have to make sure all new staff are well trained, too. "It needs to be a constant process of training and retraining," advises Dyson.
Even small things, such as not chucking the linen out into the hallway - which can spread infestation - or the dangers of putting pillow cases back into the storeroom, need to be reiterated.
"Once you are aware that they are in a room, it is vital that you isolate that room and get it sprayed," he adds.
Ten things you always wanted to know about bedbugs but were too squeamish to ask…
Bedbugs come from the insect family Cimicidae, and there are about 30 species around the world.
They are about 5mm long, mahogany brown and similar in shape to a ladybird.
They are most active at night and feed solely on blood.
Bugs will feed once a week but can go for many months without food.
They cannot fly or climb on glass or metal but will crawl more than 30m for a meal.
They can migrate through walls, ceilings and central-heating ducts.
They can eat up to seven times their body weight and after feeding will swell and become reddened.
Telltale signs of infestation are minute, often black, blood spots on sheets, headboards and pillows, and behind mirrors and pictures
Females lay batches of 10-50 eggs and their life cycle is between five weeks and four months, depending on temperature and food availability.
They give off a distinct, sweet "almond-like" smell, which is one way to spot whether a room is infested.