What do fleas do to humans? - briefly
Fleas bite the skin, ingest blood, and their saliva provokes itching, redness, and possible allergic dermatitis. Occasionally they transmit pathogens such as Yersinia pestis or Rickettsia species, causing serious infections.
What do fleas do to humans? - in detail
Fleas are external parasites that feed on human blood after piercing the skin with their mouthparts. Their bites produce localized irritation, characterized by small, red papules that often become intensely itchy. Repeated feeding can lead to:
- Secondary bacterial infection from scratching, commonly caused by Staphylococcus or Streptococcus species.
- Allergic reactions ranging from mild erythema to severe urticaria or anaphylaxis in sensitized individuals.
- Transmission of pathogenic microorganisms, notably the bacterium Yersinia pestis (plague) and, less frequently, Rickettsia spp. (murine typhus).
Flea saliva contains anticoagulant proteins that facilitate blood ingestion; these proteins trigger histamine release, intensifying pruritus and swelling. In susceptible hosts, the immune response may generate a hypersensitivity to flea antigens, resulting in chronic dermatitis known as flea allergy dermatitis.
Infestations often originate from contact with infested pets, bedding, or environments where flea life stages (egg, larva, pupa) develop. Adult fleas can survive several weeks on a human host, but they require a warm, humid microhabitat for reproduction, limiting human-to-human transmission. Effective control involves:
- Treating domestic animals with appropriate insecticides.
- Cleaning living spaces, vacuuming carpets, and washing bedding at high temperatures.
- Applying environmental insect growth regulators to interrupt the life cycle.
Failure to address a flea problem can exacerbate skin lesions, increase the risk of disease spread, and cause persistent discomfort. Prompt identification and integrated pest management reduce these health impacts.