What do bedbugs transmit when they bite? - briefly
Bedbug bites are not known to transmit any diseases; they cause only localized skin irritation, itching, and occasionally allergic reactions.
What do bedbugs transmit when they bite? - in detail
Bedbug feeding involves the injection of saliva that contains a complex mixture of biologically active molecules. The saliva delivers anticoagulants that prevent clotting, vasodilators that increase blood flow, and anesthetic proteins that reduce the host’s perception of the bite. These components provoke a local inflammatory response, producing the characteristic itchy, red welts.
The primary health effect of a bite is an allergic reaction to the salivary proteins. Sensitised individuals may experience severe pruritus, swelling, and, in rare cases, systemic hypersensitivity. Repeated scratching can break the skin barrier, allowing opportunistic bacteria such as Staphylococcus aureus or Streptococcus pyogenes to enter and cause secondary cellulitis or impetigo.
Extensive epidemiological studies have failed to demonstrate that bedbugs act as vectors for human pathogens. Laboratory investigations have detected viral and parasitic nucleic acids—including hepatitis B virus, HIV, and Trypanosoma cruzi—within bedbug tissues, but transmission to a host has not been observed under controlled conditions. The consensus among entomologists and public‑health authorities is that bedbugs do not reliably transmit infectious agents during feeding.
In summary, the substances delivered by a bedbug bite consist of salivary proteins that cause anticoagulation, vasodilation, and anesthesia, leading to an allergic skin reaction. The main medical concern is the potential for secondary bacterial infection following excessive scratching; credible evidence of direct pathogen transmission by bedbugs remains absent.