What do fleas transmit through their bites? - briefly
Flea bites can transmit the bacterium Yersinia pestis, the agent of plague, and occasionally Bartonella henselae, which causes cat‑scratch disease. They are not recognized as vectors for viral infections.
What do fleas transmit through their bites? - in detail
Fleas are hematophagous ectoparasites whose saliva introduces a range of pathogenic organisms into the host’s skin. The primary agents transmitted during feeding include bacteria, protozoa, and allergens that provoke immune reactions.
Bacterial pathogens carried by flea bites:
- Yersinia pestis – the causative agent of plague; transmitted when infected flea feces or regurgitated material enters the bite wound.
- Bartonella henselae – associated with cat‑scratch disease; flea vectors facilitate bacterial spread among feline hosts and can infect humans through bites.
- Rickettsia typhi – responsible for murine typhus; flea bites allow entry of the organism directly into the bloodstream.
Protozoal agents linked to flea activity:
- Dipylidium caninum – a tapeworm whose larval cysticercoid develops within the flea; ingestion of an infected flea, rather than the bite itself, leads to human infection. The flea remains a critical vector in the life cycle.
Viral transmission by fleas is not well established; current evidence suggests limited capacity to carry arboviruses, and direct bite transmission remains unconfirmed.
Allergic and inflammatory reactions:
- Flea saliva contains anticoagulant proteins that trigger hypersensitivity in susceptible individuals, resulting in papular urticaria, pruritic dermatitis, or localized erythema. Repeated exposure can exacerbate the immune response, leading to chronic skin lesions.
In summary, flea bites serve as a conduit for bacterial infections such as plague, cat‑scratch disease, and murine typhus, act as an intermediate host for certain tapeworms, and provoke allergic skin reactions. Awareness of these risks is essential for accurate diagnosis and effective vector‑control strategies.