|This 2006 photograph depicted an oblique-dorsal view of a bedbug nymph, Cimex lectularius, as it was in the process of ingesting a blood meal from the arm of a voluntary human host.|
Bedbugs are not vectors in nature of any known human disease. Although some disease organisms have been recovered from bedbugs under laboratory conditions, none have been shown to be transmitted by bedbugs outside of the laboratory.
The common bedbug is found worldwide. Infestations are common in the developing world, occurring in settings of unsanitary living conditions and severe crowding. In North America and Western Europe, bedbug infestations became rare during the second half of the 20th century and have been viewed as a condition that occurs in travelers returning from developing countries. However, anecdotal reports suggest that bedbugs are increasingly common in the United States, Canada, and the United Kingdom. (See the link to copyright information below)
C. lectularius inject saliva into the blood stream of their host to thin the blood, and to prevent coagulation. It is this saliva that causes the intense itching and welts. The delay in the onset of itching gives the feeding bedbug time to escape into cracks and crevices. In some cases, the itchy bites can develop into painful welts that last several days.
Bedbug bites are difficult to diagnose due to the variability in bite response between people, and due to the change in skin reaction for the same person over time. It is best to collect and identify bedbugs to confirm bites. Bedbugs are responsible for loss of sleep, discomfort, disfiguring from numerous bites and occasionally bites may become infected.