What do rats release when they bite?

What do rats release when they bite? - briefly

When a rat bites, its saliva introduces bacteria—most notably Streptobacillus moniliformis, the agent of rat‑bite fever—as well as possible viruses and allergens. These microorganisms can cause infection if the wound is not promptly cleaned and treated.

What do rats release when they bite? - in detail

Rats do not inject venom, but their bites introduce a complex mixture of biological materials into the wound. The primary component is saliva, which contains enzymes, proteins, and a resident microbial community. Salivary enzymes such as amylase and lysozyme serve digestive and antimicrobial functions, yet they also facilitate the survival of pathogenic organisms.

The microbial load delivered by a rat bite includes:

• Bacterial agents
  • Streptobacillus moniliformis: the causative agent of rat‑bite fever, producing systemic symptoms such as fever, rash, and arthritis.
  • Leptospira interrogans: spirochetes responsible for leptospirosis, capable of causing renal failure and hepatic dysfunction.
  • Staphylococcus aureus and Streptococcus species: common skin flora that can become opportunistic pathogens in the wound.
• Viral particles
  • Hantaviruses: transmitted through aerosolized rodent secretions; direct bite transmission is rare but documented in isolated cases.
• Parasitic elements
  • Bartonella spp.: bacteria that may also be carried by ectoparasites such as fleas, potentially introduced during a bite.
• Allergenic proteins
  • Salivary proteins that can trigger hypersensitivity reactions in sensitized individuals, leading to localized swelling or systemic anaphylaxis.

In addition to these biological agents, a rat bite can deposit external contaminants:

• Foreign debris: fur, skin scales, and environmental dust embedded in the oral cavity.
• Oral microbiome residues: a diverse assemblage of commensal and opportunistic microbes that may colonize the wound if not promptly decontaminated.

The combined effect of these substances can result in infection, inflammation, and tissue damage. Prompt wound cleaning, thorough irrigation, and appropriate antimicrobial therapy are essential to mitigate the risk of systemic disease.