What can a rat transmit? - briefly
Rats are vectors for bacterial infections such as leptospirosis, salmonellosis, plague, and rat‑bite fever, as well as viral diseases like hantavirus and various parasitic agents transmitted by fleas and mites. These pathogens spread through bites, contaminated urine, feces, or aerosolized particles from rodent excreta.
What can a rat transmit? - in detail
Rats are vectors for a wide range of infectious agents that affect humans and domestic animals. Transmission occurs through direct contact with the animal, exposure to contaminated urine, feces, or saliva, ingestion of food or water tainted by rodent waste, and via ectoparasites such as fleas and mites.
Key bacterial pathogens include:
- Leptospira spp., causing leptospirosis through contact with urine‑contaminated surfaces.
- Salmonella enterica, leading to salmonellosis after ingestion of food contaminated by feces.
- Streptobacillus moniliformis, responsible for rat‑bite fever following bites or scratches.
- Yersinia pestis, the agent of plague, transmitted by flea bites that have fed on infected rodents.
- Bartonella henselae, occasionally spread by fleas and associated with cat‑scratch disease‑like symptoms.
Viral agents transmitted by rats comprise:
- Hantavirus, primarily Hantaan and Seoul strains, spread by inhalation of aerosolised rodent droppings.
- Lymphocytic choriomeningitis virus (LCMV), transferred through exposure to urine, feces, or contaminated nesting material.
- Rat hepatitis E virus, which can cause acute hepatitis after ingestion of contaminated food or water.
Parasitic infections linked to rodent hosts include:
- Hymenolepis nana (dwarf tapeworm), acquired by ingesting eggs from contaminated food.
- Angiostrongylus cantonensis (rat lungworm), leading to eosinophilic meningitis when humans consume raw or undercooked intermediate hosts such as snails.
Fungal pathogens are less common but have been documented:
- Cryptococcus neoformans, found in rodent excreta, can cause cryptococcal meningitis in immunocompromised individuals.
Transmission pathways are summarized as:
- Direct contact with live rats or their body fluids.
- Inhalation of aerosols containing dried droppings or urine.
- Ingestion of contaminated food, water, or raw produce.
- Bites or scratches delivering bacterial agents.
- Ectoparasite vectors (fleas, mites) that feed on infected rodents and subsequently bite humans.
Control measures focus on rodent population management, sanitation to prevent contamination of food and water supplies, protective equipment for workers handling rodents, and prompt medical evaluation of suspected exposures. Early diagnosis and appropriate antimicrobial or antiviral therapy reduce morbidity and prevent outbreaks.