How do mice transmit fungal infections? - briefly
Mice disseminate fungal pathogens via contaminated fur, saliva, urine, and feces, which deposit spores onto bedding, food, and surfaces that other rodents subsequently inhale or ingest. Grooming and close contact within colonies further amplify spore spread throughout the population.
How do mice transmit fungal infections? - in detail
Mice serve as vectors for a variety of fungal pathogens through several well‑characterized pathways. Direct physical contact transfers viable spores when animals groom each other or share nesting material. Contaminated fur and paws deposit conidia onto surfaces that other rodents subsequently touch, establishing a chain of indirect transmission.
Aerosolisation of fungal elements occurs during vigorous respiration, sneezing, or cage cleaning. Air‑borne spores settle on bedding, feed, and equipment, creating an inhalation risk for co‑habiting mice and for personnel handling the colony. Fecal shedding adds a gastrointestinal component: infected mice excrete viable yeast or hyphal fragments, which persist in droppings and contaminate the environment when bedding is disturbed.
Vertical transmission is documented for certain opportunistic fungi; infected females can pass organisms to offspring in utero or through milk, seeding the next generation without external exposure. Additionally, wounds or skin lesions provide portals for dermatophyte invasion, enabling spread through biting or scratching.
Key fungal agents observed in murine models include:
- Candida spp. – disseminated via bloodstream, feces, and grooming.
- Aspergillus spp. – released as airborne conidia during cage cleaning.
- Pneumocystis murina – transmitted primarily through respiratory droplets.
- Histoplasma capsulatum – shed in urine and feces, contaminating bedding.
- Dermatophytes (e.g., Trichophyton spp.) – spread by direct skin contact.
Factors influencing transmission efficiency:
- Housing density – higher occupancy increases contact rates.
- Ventilation – poor airflow promotes aerosol persistence.
- Bedding material – porous substrates retain spores longer.
- Immunological status – immunocompromised mice exhibit higher fungal loads, enhancing shedding.
- Sanitation practices – infrequent cage changes allow accumulation of viable propagules.
Control measures focus on environmental decontamination, HEPA filtration to reduce airborne spores, routine health monitoring for fungal colonization, and segregation of infected individuals. Understanding each pathway allows targeted interventions that limit fungal spread within laboratory and wild rodent populations.