Bed bugs (Cimex lectularius), bed-bugs, or bedbugs, have reestablished themselves as an urban pest problem in the United States and worldwide over the past decade. Resistance of Cimex lectularius, the common bed bug, to insecticides and pesticides is one reason for bed bugs being back in the news.
Bed bugs have been associated with humans for thousands of years and have been pestering humans for at least 3550 years. Their highly effective and adaptive nature allows them to live for 12 months without feeding and even 1.5–2 years in colder environments. The blood-sucking parasite has been especially common in areas of extreme poverty where people do not have the proper resources to control them. Cimex lectularius was a major pest species until after World War 2. With the development of powerful pesticides bed bugs nearly disappeared even in developing countries until recently, where they have made a rapid comeback in 1990s onward.
Bed bugs are often found in beds and bedding, in crevices in furniture, clothing, carpets, and curtains. Public transportation may also harbor these pests. Warmth and carbon dioxide are key factors they migrate to in finding a host. They emit an easily recognized, offensive odor caused by an oily secretion produced by special glands. Adult bed bugs are about 5 mm long, oval shaped and flattened wingless insects resembling confetti that can move quite rapidly when disturbed. They may increase in size 150 to 200% while feeding. Adults are reddish-brown; the immatures are yellowish-white. Each adult female produces 200–500 eggs in her lifetime. Feeding mostly occurs at night on sleeping people. However, if bed bugs are starving they will feed during the day, especially in darkened rooms. Unlike lice, bed bugs do not stay on people but stay only to take blood-meals; occasionally they may stay on homeless people who do not change their clothes. In the absence of people, bed bugs will feed on other hosts, including rabbits, rats, mice, bats, poultry and wild birds. Bed bugs can be major pests in commercial poultry operations and are more frequently encountered in floor-raised poultry and roost facilities rather than in caged systems.
When feeding, a bed bug penetrates a host's skin with two tubelike proboscises. The first proboscis injects saliva containing a mixture of anticoagulant, anesthetic and vasodilatory compounds (such as nitric oxide). The other is used to obtain the blood meal, which requires about 5 to 10 minutes. Small, granular, reddish-black feces are released after engorgement. Because bed bug saliva contains anesthetic compounds, bites are painless and usually not felt until several hours later. The typical skin lesion is an itchy bump, 5 mm to 2 cm in diameter with a blister and blood-stained crust. 6 The itch is more intense in those who experience repeated bites. Heavy infestations may cause anemia and anaphylactic reaction. Skin lesions resolve spontaneously within 2–6 weeks, but permanent pigmentation may follow.
The health impact of bed bug infestation can be significant. Although these pests are not generally considered as disease vectors (except hepatitis, especially hepatitis B virus), they are associated with skin effects, unpleasant odor due to oily chemical secretions, allergies and psychological stress. Numerous researchers have suggested that bed bugs may transmit a variety of diseases, including roundworm infections, leishmaniasis, Chagas' disease and over 40 other pathogens reportedly found in bedbugs:
Full eradication is difficult and repeated treatment may be required. Difficulties in treatment and prevention of spread are due to lack of public awareness of the pests. An "efficient search-and-destroy" operation must be imposed, starting by removing all bed linens and washing at a temperature >60°C, then by checking and dismantling all furniture to access all bed bug hiding places, to identify and destroy eggs, nymphs, and adults. Alternatively, a dog specifically trained to detect bedbugs' characteristic odor can do the search. Attractive traps can also be used in highly infested locations. It is always best to vacuum first to reduce the overall bed bug population, but complete success is unlikely without remnant insecticides for residual protection against bed bug survivors. Fumigants, which are too frequently used by nonprofessionals, do not penetrate deeply into bed bug hiding places, fail to provide any residual protection, and can pose an immediate health risk to the user.6