What infection does a flea transmit? - briefly
Fleids serve as the main vector for Yersinia pestis, the bacterium that causes plague. They can also transmit Rickettsia typhi (murine typhus) and various Bartonella species that cause zoonotic infections.
What infection does a flea transmit? - in detail
Fleas are competent vectors for several bacterial pathogens that cause human disease. The most significant is the bacterium responsible for plague. When an infected rodent’s blood is ingested by a flea, the organism multiplies within the insect’s foregut, forming a blockage that forces the flea to regurgitate bacteria into subsequent hosts during feeding. This mechanism leads to rapid transmission of Yersinia pestis, producing bubonic, septicemic, and pneumonic forms of the disease.
Other infections transmitted by fleas include:
- Bartonella henselae: causes cat‑scratch disease; acquired when flea feces contaminate scratches or bites from cats.
- Rickettsia typhi: agent of murine typhus; spread when fleas excrete the organism onto the skin or mucous membranes during a bite.
- Yersinia pseudotuberculosis: occasionally transmitted via flea bites, resulting in gastrointestinal illness.
Clinical presentation varies by pathogen. Plague typically begins with painful lymphadenopathy (buboes), fever, and chills; untreated septicemic plague can progress to shock and organ failure. Murine typhus manifests as abrupt fever, headache, rash, and myalgia. Bartonella infection produces regional lymphadenitis, fever, and, in some cases, hepatosplenomegaly.
Diagnosis relies on microbiological culture, polymerase chain reaction, and serology. Prompt antimicrobial therapy—streptomycin or doxycycline for plague, doxycycline for murine typhus and Bartonella—reduces mortality.
Preventive measures focus on controlling flea populations on rodents and domestic animals, using insecticidal treatments, maintaining clean environments, and avoiding contact with wild rodents. Personal protection includes wearing gloves when handling animals and applying repellents to exposed skin.