What can be contracted from a flea bite? - briefly
Flea bites can transmit bacterial infections such as plague (Yersinia pestis) and murine typhus, as well as parasitic agents like the tapeworm Dipylidium caninum, and they may also provoke allergic skin reactions.
What can be contracted from a flea bite? - in detail
Flea bites may introduce a range of pathogens into the human body. The most clinically significant agents are bacterial, though viral and parasitic transmissions have been reported in rare cases.
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Yersinia pestis – the causative organism of plague. Transmission occurs when infected fleas feed on humans, depositing bacteria along with saliva. Typical presentation includes sudden fever, painful swollen lymph nodes (buboes), and, in severe forms, septicemia or pneumonic involvement. Incubation averages 2–6 days. Prompt antibiotic therapy (streptomycin, gentamicin, doxycycline) is essential to prevent mortality.
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Rickettsia felis – responsible for flea‑borne spotted fever. Symptoms begin 5–14 days after exposure and consist of fever, headache, rash, and occasional eschar at the bite site. Doxycycline is the treatment of choice; the disease is usually self‑limiting if therapy is initiated early.
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Bartonella henselae – primarily associated with cat‑scratch disease but also transmitted by flea saliva. Clinical features include regional lymphadenopathy, low‑grade fever, and, in immunocompromised patients, bacillary angiomatosis. Azithromycin or doxycycline are effective.
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Rickettsia typhi – agent of murine typhus. Fleas acting as vectors deposit bacteria during feeding, leading to fever, chills, rash, and headache after an incubation of 1–2 weeks. Doxycycline remains the standard therapy.
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Francisella tularensis – causes tularemia, a zoonotic infection that can be acquired through flea bites from infected rodents. Presentation varies by route of entry; cutaneous forms show ulcerated lesions and regional lymphadenopathy. Gentamicin or streptomycin are recommended.
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Allergic and inflammatory reactions – local erythema, swelling, and pruritus are common. Secondary bacterial infection of the bite site (often Staphylococcus aureus or Streptococcus pyogenes) may develop, requiring topical or systemic antibiotics based on severity.
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Viral agents – rare transmission of certain arboviruses, such as Toscana virus, has been documented. Clinical picture typically involves febrile illness with neurologic manifestations; supportive care is the mainstay.
Awareness of these possible infections informs timely diagnosis and treatment, reducing the risk of complications. Preventive measures include regular flea control on pets, environmental sanitation, and protective clothing when exposure to flea‑infested habitats is likely.