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 size of bed bug bites varies with a number of different factors. Bed bugs inject an anti-coagulant along with their saliva when they pierce the skin to take a blood meal. This anti-coagulant is mostly responsible for how a person reacts to the bite and determines the size of the bug’s bite. Since people will have various sensitivities to the bed bug’s bite, the size of the bite will vary, as well. Another factor that influences the size of a bed bug reaction is the number of times a person is bitten. Bite reactions of people bitten many times are also variable, and their response may be either more or less intense as the number of bites increases.