What do fleas do to people? - briefly
Fleas bite human skin, causing painful, itchy welts and can transmit bacterial infections such as plague, murine typhus, or Bartonella. Their saliva may also provoke allergic reactions in sensitive individuals.
What do fleas do to people? - in detail
Fleas are blood‑feeding ectoparasites that can bite humans, injecting saliva that contains anticoagulants and irritants. The bite produces a small, red, itchy papule that may develop into a wheal or a cluster of papules when several fleas feed in close proximity. Repeated exposure often leads to sensitization, causing more intense itching, swelling, and secondary bacterial infection from scratching.
Beyond the immediate skin reaction, fleas serve as vectors for several pathogens:
- Yersinia pestis – the bacterium that causes plague; transmission to humans occurs when an infected flea bites or when flea feces contaminate a wound or mucous membrane.
- Rickettsia typhi – agent of murine typhus; fleas acquire the organism from infected rodents and transmit it through fecal contamination of bite sites.
- Bartonella henselae – associated with cat‑scratch disease; fleas can harbor the bacterium and spread it to humans via bites or contaminated flea debris.
Allergic reactions may range from mild local pruritus to severe urticaria or anaphylaxis in highly sensitized individuals. In rare cases, massive flea infestations (known as “pseudopelade” or “flea dermatitis”) can result in anemia, especially in children, the elderly, or immunocompromised patients, due to cumulative blood loss.
Control measures focus on eliminating flea reservoirs (pets, rodents), maintaining environmental hygiene, and applying approved insecticides or topical antiparasitic treatments to hosts. Prompt wound care and antihistamines reduce symptom severity, while antibiotics are required for confirmed vector‑borne infections.