Description

• Nocturnal obligate blood parasites residing in furniture and bedding
• 5 to 7 mm oval, reddish brown, flat, wingless morphology
• Microscopic evidence suggests a mature bed bug Cimex lectularius is approximately the size of an apple seed (1).

Epidemiology

Incidence

• Bed bug infestations are increasing in incidence and becoming more difficult to treat (2).
• Resurgence due to changes in pesticide, increased travel, use of secondhand furniture, and high turnover rates of hotel guests

Prevalence

• Infestations have increased by 10–30% across the United States (1) in public places (schools, hospitals, hotels/motels, aircraft) over the past decade (3).
• The global population of bed bugs (C. lectularius and Cimex hemipterus, family Cimicidae) has undergone a significant resurgence since the late 1990s. This is likely due to an increase in global travel, trade, and the number of insecticide-resistant bed bugs. The global bed bug population is estimated to be increasing by 100–500% annually (4). It will be interesting to see what (if any) impact the COVID-19 travel restrictions have on the incidence of infestation.
• There are over 75 species of Insecta: Hemiptera: Cimicidae (“bed bugs”) with the two genera and species implicated in human infestations being C. lectularius and C. hemipterus (1).
• C. lectularius lives in urban environments and C. hemipterus lives in tropical climates.

Etiology and Pathophysiology

• Insect family Cimicidae
• Three species bite humans: C. lectularius, C. hemipterus, and Leptocimex boueti (3)[B].
• Most prevalent species is C. lectularius (3)[B]
• Found in tropical and temperate climates
• Hide in crevices of mattresses, box springs, headboards, and baseboards
• Infestations occur in hotels/motels, hospitals, cinemas, vehicles, aircraft, and homes.
• Unlike other infestations, they are not associated with hygienic deficiencies.
• Reactions range from an absent or minimal response to the typical pruritic, erythematous maculopapular rash. Less commonly, there is an urticarial or anaphylactoid response.
• Skin reactions are due to host immunologic response to parasite salivary proteins.
• Urticarial reactions are mediated via immunoglobulin (Ig) G antibody response to salivary proteins (5)[B].
• Bullous reactions caused by an IgE-mediated hypersensitivity to nitrophorin in bug saliva (5)[B].
• Bugs are attracted to body warmth and exhaled carbon dioxide (6).
• Bites do not transmit other known pathogens.

Risk Factors

• Immunocompromised
• High hotel turnover
• Secondhand furniture in home

General Prevention

• Traps typically use carbon dioxide and heat to attract and trap bugs but can be cost prohibitive (7)[B].
• Vector control: Vacuum regularly; reduce clutter; seal cracks in walls; inspect luggage and clothing.
• Launder all bedding and clothing in >130°F (50°C) for 2 hours or place in 20°F (−5°C) or cooler environment for at least 5 days.
• If present in the home, eradicate using professional extermination services. Some pest control companies use canines to detect live bed bugs and eggs based on pheromones from the bed bugs (7)[B].