Bed bugs don't appear to spread disease, researchers conclude in a new study that will offer little comfort to those who are unsuccessfully waging war against the tiny critters.

Dr. Richard deShazo of the University of Mississippi Medical Center in Jackson, Miss. and Jerome Goddard, a medical entomologist at Mississippi State University, decided to examine the health effects of bed bugs after finding there had been little good research on the tiny blood suckers.

They reviewed dozens of previously published articles to see whether bed bugs (Cimex lectularius) are transporters of communicable disease.

The spread of more than 40 human diseases has been attributed to bed bugs over the centuries, the authors say, including plague, smallpox and HIV. But they conclude that there is little evidence that such transmission has ever occurred.

"To our knowledge, no study to date has demonstrated bed bug 'vector competence' (the ability to acquire, maintain, and transmit an infectious agent)," the authors conclude in JAMA, the Journal of the American Medical Association.

While bed bugs may be more nuisance than health hazard, they still cause plenty of problems in people sensitive to their bites, most notably itching and, occasionally, allergic skin reactions. Not everyone bitten by bed bugs develops a reaction, the authors say, noting that no one yet knows why.

"We're not absolutely sure how folks react to bites because it's so unusual that we get large numbers of them into the clinic to study," says Goddard.

For those who are left itching and scratching after a night in bed, there remains no consistently effective treatment.

"Treatments that have been used with varying results include antibiotics, antihistamines, topical and oral corticosteroids and epinephrine (adrenaline)," they write.

What's more, no repellents for the insects have been demonstrated conclusively to be effective, the authors say, so "prevention of bed bug bites is best achieved with avoidance."

Finally, after reviewing studies on methods to eradicate bed bugs, the authors could no find no effective, evidence-based methods.

After being practically eradicated from North America, there has been a resurgence in bed bug populations across North America. Part of the reason is the ban on older insecticides, such as DDT, that used to keep the bug populations low. What's more, the bugs have learned to become resistant to the pesticides that remain in use.

Goddard says international travel and immigration are helping to fuel their spread.

"They're parasites, they suck blood, so they're brought into someplace in someone's luggage or belongings, they start living there it has nothing to do with how clean you are," he says. "Some of the cases I've investigated, they've been five-star hotels."

Bed bugs are likely to be more problematic in the future, Goddard and deShazo write, as they urge for more study and public education on the bugs, as well as the development of more effective repellents.

For now, the best way to ensure that you wake up bed bug bite-free is to take a good look at the mattress you're about to sleep on to check for blood spots on bedding.

"Just follow some good housekeeping practices," advises Reg Ayre, the manager of Healthy Environments for Toronto Public Health. "A good vacuuming, laundering, decluttering homes, basic common sense, can go a long way to controlling an infestation."

Some tips to prevent a bed bug infestation

  1. Vacuum all crevices on your mattress, bed frame, baseboards and any objects close to the bed. Use the nozzle attachment on a vacuum to capture the bed bugs and their eggs. If you suspect you have bugs, vacuum daily and empty the vacuum immediately.
  2. Consider covering your pillows and mattress with a plastic cover.
  3. Wash all your linens in the hottest water possible and place them in a hot dryer for 20 minutes.
  4. Follow the same advice for any second-hand clothing or soft items that come into your home.
  5. Upon returning home from a vacation, keep your luggage in an isolated area of your home, such as the garage. Wash all your clothes in the same ways as described above.
  6. Remove all unnecessary clutter from under your bed.
  7. Seal cracks and crevices between baseboards, on wood bed frames, floors and walls with caulking. Repair or remove peeling wallpaper, tighten loose light switch covers, and seal any openings where pipes, wires or other utilities come into your home (pay special attention to walls that are shared between apartments).
  8. Monitor daily by setting out glue boards or sticky tape (carpet tape works well) to catch the bed bugs. Closely examine any items that you are bringing into your home.
  9. Consult professional pest control services and discuss options that pose the least risk to humans and the environment.