The likelihood of bed bugs increases if the affected individual has been traveling, or if they have acquired used beds or furnishings before symptoms started to appear. Bed bugs also are suspect if you wake up with itchy welts you did not have when you went to sleep. It’s important to recognize, however, that not all bite-like reactions are due to bed bugs. Confirmation requires finding and identifying the bed bugs, shed skins, fecal spots, etc., which often requires the help of a professional. (Other possible sources of irritation that may be mistaken for bed bugs are discussed in University of Kentucky entomology fact sheet ENT-58, Invisible Itches: Insect and Non-Insect Causes).
Infestations with bedbugs date back to ancient Egypt.1 The incidence of bedbugs in developed countries decreased in the 1940s because of the availability of more effective pesticides (especially DDT) and improved economic and social conditions.2 In the past decade, however, a significant resurgence of bedbug populations has occurred. This is attributed to a combination of factors, including increased pesticide resistance, more frequent travel, lack of public awareness, and inadequate pest control programs.3 In a 2010 survey, 95 percent of more than 500 U.S. pest management companies reported encountering a bedbug infestation during the preceding year, compared with only 25 percent of companies during 2000.4 Bedbugs spread actively by migrating from one infested room to another, often through ventilation ducts. They also spread passively, carried in the seams of travelers’ luggage, bedding, or furniture.5 Bedbugs do not travel directly on human hosts.6
The biggest problem with these bites is that, depending on the persons skin and their tolerance to bacteria, their appearance is different on different types of people. I have noticed in the past that if I get bitten by a mosquito, I get a rather large red mark (even without scratching), whereas my husbands skin hardly shows any signs of the bite.
All of the stages of bed bugs are visible, at least if you don't need reading glasses and you have a sufficient amount of light. So if you're looking closely enough, you can even see bugs in the nymphal first instar stage. A fecal spot, for its part, can be as large as a bed bug itself in terms of the area it covers. The spots are basically digested blood, so most are dark in color. On a white mattress, they stand out pretty well.
Items that cannot be placed in a washer or dryer can sometimes be de-infested by wrapping them in plastic and placing them outdoors in a hot, sunny location for at least a day (for example, on pavement or in a closed vehicle parked in the sun). Packing items loosely in garbage bags and elevating objects off the ground helps the heat permeate further, and will make it harder for bugs to find a cool place to hide. Monitoring with a thermometer is prudent to ensure that a temperature of at least 120°F is achieved wherever the bugs may be.
While cleaning up infested areas will be helpful in controlling bedbugs, getting rid of them usually requires chemical treatments. Because treating your bed and bedroom with insecticides can be harmful, it is important to use products that can be used safely in bedrooms. Do not treat mattresses and bedding unless the label specifically says you can use them on bedding.