William Hung, the chief executive of Johnson Group, a local pest control firm, says the volume of bed bugs cases he's handled has risen sharply in the past five years. His firm handled 105 cases in 2009 and more than 500 last year. Bed bugs are a common problem for people living in public housing estates, because of the population density.

The small wingless insects were once a major domestic problem worldwide. Their prevalence declined with the widespread use of DDT from the mid-20th century. But there seems to be a recent resurgence of the blood-sucking insect globally, says the department.

International travel, immigration, changes in pest control practices, and insecticide resistance may have contributed to the resurgence in developed countries, say researchers from the University of Mississippi Medical Centre, who published a report in the journal on the health and medical effects of bed bugs, and control and eradication strategies.

Swati Maheshwari, a PhD student at Baptist University, says bed bugs took over her life for about three months last summer after she bought used furniture that was infested with the creatures. "It was seriously harrowing. I had marks and welts all over my skin, arms and my legs," she says.

The bugs first appeared in the bedroom of her domestic helper, and then spread to her room and that of her 18-month-old daughter. She and her husband hired a pest control firm, which administered three separate treatments. As the bugs kept attacking, Maheshwari resorted to desperate measures, such as repeatedly soaking her mattress with boiling water. Her solution in the end was to throw out the HK$14,000 mattress.

Bed bugs are difficult to treat because they live and lay eggs in the cracks of bed frames and skirting panels on walls, and burrow inside mattresses. Most insecticides won't kill the eggs, which have a 14-day lifecycle. People might think the problem has gone away only for fresh eggs to hatch. Bed bugs live only on human blood and tend to feed on slumbering folks at night. Their bites can be itchy for days and cause rashes.

The bugs attach themselves to clothing and bags, and then move from room to room, and home to home.

Hung says 90 per cent of cases involve homes with maids who have stayed in hostels, which are often infested.

Filipina helper Liz (not her real name) battled bed bugs in June 2012 in Tai Wong Street in Wan Chai. She says the pests covered the 500 sq ft hostel, which was home to 10 helpers. "They were on the walls, on my towels and on the carpet." Travellers also spread the problem. Bed bugs are a bigger issue in hotels than the industry will admit. "People don't talk about it because it's taboo, but it's definitely happening," says Liz Lycette, a housekeeping consultant.

She knows of lawsuits in the US where guests sued hotel owners for letting them stay in infected rooms. Lycette says hotel management may use dogs to sniff out the bugs. The insects defecate blood, leaving a distinctive odour, likened to the smell of rotting raspberries. An infected room, and those adjacent, is closed for chemical treatment and heat cleaning of bedding and furniture.

The best way to check for bed bugs is look at the sheets, Lycette says. If the sheets show a trail of reddish-black dots, the room is probably infected.

Hung now has a ritual of checking each corner of a hotel room when checking-in, looking for faecal debris. He then sprays his rooms with a repellent, and when he returns home sprays his luggage with insecticide and leaves it out in the sun for a spell.

Many families with the problem simply cannot afford treatment, which can be about HK$10,000 for a 1,000 sq ft flat.

He's monthly income is less than that and she thought she was lucky when a social worker arranged a free treatment. Two days later, though, the bugs were back.
 

How to eradicate bed bugs on the cheap

Battling bed bugs but can't afford expensive pest control services? Here are some things you can do that may help keep the bites at bay.

• Regular cleaning and vacuuming of premises, thorough laundering of bedding and clothing, and environmental sanitation management are essential for prevention of bed bug infestation, says the Food and Environmental Hygiene Department.
• Inspect bedding and clothing regularly, maintain non-humid domestic environments, avoid use of second-hand furniture, promptly replace loose wallpaper, and seal cracks and crevices.
• Remove bedroom clutter where bed bugs can hide, and wash bed linens in hot water and heat-dry them in a dryer, says Fang Zhu, a scientist from Washington State University. Fang is leading research on the identification of the genes responsible for pesticide-resistance in bed bugs.
• Exposing bed bug-infested clothing or other small items to freezing temperatures may be a viable control option, according to an article published last month in the . The authors recommend that the items be placed in plastic bags and that they remain in the freezer for two to four days, depending on the freezer's temperature.