What is injected after a tick bite? - briefly
Ticks inject saliva that contains anticoagulants, anesthetic compounds, and immunomodulatory proteins, which facilitate feeding and can transmit pathogens such as bacteria, viruses, or protozoa. This mixture may also include enzymes that suppress host immune responses.
What is injected after a tick bite? - in detail
When a tick attaches and begins feeding, it introduces a complex cocktail of biologically active substances directly into the host’s skin. These compounds serve to facilitate blood ingestion, suppress host defenses, and, in many cases, transmit infectious agents.
The primary constituents of the tick’s injection include:
- Anticoagulants – molecules such as apyrase and thrombin inhibitors that prevent clot formation, ensuring a steady flow of blood.
- Anti‑inflammatory agents – proteins that block prostaglandin synthesis and inhibit cytokine release, reducing pain and swelling at the bite site.
- Immunomodulators – salivary proteins that interfere with complement activation and antibody binding, weakening the host’s immune response.
- Enzymes – proteases and lipases that degrade extracellular matrix, allowing deeper penetration of the feeding apparatus.
- Cement proteins – substances that harden around the mouthparts, anchoring the tick securely to the skin.
- Pathogens – bacteria (e.g., Borrelia burgdorferi, Anaplasma phagocytophilum), protozoa (e.g., Babesia microti), rickettsiae, and viruses (e.g., Powassan virus) that may be transmitted during the feeding process.
The volume of fluid delivered is minute, typically measured in nanoliters, but the biological impact is significant because the mixture is precisely adapted to evade detection and promote pathogen survival. Salivary composition varies among tick species and developmental stages, influencing the spectrum of diseases they can convey. Understanding each component’s role aids in developing vaccines and therapeutic agents aimed at interrupting transmission.