What diseases do fleas transmit? - briefly
Fleas are vectors for several bacterial infections, including plague (Yersinia pestis), murine typhus (Rickettsia typhi), flea‑borne spotted fever (Rickettsia felis), cat‑scratch disease (Bartonella henselae), and occasionally tularemia (Francisella tularensis).
What diseases do fleas transmit? - in detail
Fleas serve as vectors for several bacterial pathogens that cause serious human illnesses. The most notorious agent is Yersinia pestis, the bacterium responsible for plague. Transmission occurs when an infected flea bites a host, injecting bacteria from its foregut. Clinical forms include bubonic plague (painful lymphadenopathy), septicemic plague (systemic infection with fever, hypotension, hemorrhage), and pneumonic plague (lung involvement, high mortality without prompt antibiotics). Historically endemic in Africa, Asia, and the Americas, plague persists in rodent‑flea cycles and can reappear in urban settings where rodent control fails.
Another flea‑borne disease is murine typhus, caused by Rickettsia typhi. Fleas acquire the organism while feeding on infected rodents; subsequent bites transmit it to humans. The illness presents with abrupt fever, headache, rash, and sometimes confusion. Cases are reported worldwide, especially in warm climates where rats and their fleas thrive.
Bartonella henselae, the agent of cat‑scratch disease, can also be spread by the cat flea (Ctenocephalides felis). Humans develop regional lymphadenopathy, low‑grade fever, and occasionally hepatic or splenic lesions. The pathogen is maintained in flea feces; scratching contaminated skin facilitates entry.
Rickettsial spotted fever linked to Rickettsia felis is emerging in tropical and subtropical regions. The cat flea is the primary reservoir; infection produces fever, rash, and occasionally neurologic symptoms. Diagnosis relies on PCR or serology, and doxycycline is the treatment of choice.
Tularemia (Francisella tularensis) may be transmitted when infected fleas feed on humans or domestic animals. The disease manifests as ulceroglandular lesions, fever, and lymph node swelling. While other vectors (ticks, deer flies) are more common, flea involvement is documented in areas with high rodent populations.
Key points for each pathogen
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Plague (Y. pestis)
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Murine typhus (R. typhi)
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Cat‑scratch disease (B. henselae)
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Flea‑borne spotted fever (R. felis)
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Tularemia (F. tularensis)
- Vector: various fleas, especially those on rodents
- Transmission: bite, handling of infected animals, flea feces
- Symptoms: ulceroglandular ulcer, fever, lymphadenopathy
- Treatment: streptomycin, gentamicin, doxycycline
Control measures focus on reducing flea infestations in rodents, pets, and human dwellings, and on prompt antimicrobial therapy when infection is suspected.