How do mice transmit viruses? - briefly
Mice disseminate viral pathogens by shedding infected saliva, urine, and feces, and through direct bite or grooming contacts that introduce viruses to other animals. Ectoparasites such as fleas, mites, and ticks can acquire the virus from the host and act as vectors, while aerosolized particles and contaminated environments enable indirect transmission.
How do mice transmit viruses? - in detail
Mice disseminate viral agents through several biologically relevant pathways that are well documented in laboratory and field studies. Direct physical contact between individuals allows viruses present in saliva, nasal secretions, or skin lesions to be transferred during grooming, mating, or aggressive encounters. The exchange of bodily fluids during these interactions can result in immediate infection of susceptible hosts.
Aerosolized particles constitute another efficient route. Respiratory viruses replicate in the upper and lower airways, generating droplets that remain suspended in the environment. In confined spaces, such as nests or laboratory cages, inhalation of these droplets leads to rapid spread among cohabiting rodents. Quantitative measurements have shown viral concentrations reaching 10⁴–10⁶ PFU mL⁻¹ in exhaled air during peak shedding periods.
Fecal‑oral transmission is common for enteric and systemic viruses that are shed in large quantities in the gastrointestinal tract. Infected mice excrete virus in feces and urine, contaminating bedding, food, and water sources. Consuming or contacting these contaminated substrates introduces the pathogen to new hosts. Studies on hantavirus and lymphocytic choriomeningitis virus report stable viral particles persisting for days on moist surfaces, enhancing the likelihood of ingestion.
Vertical transmission occurs when infected females pass the virus to offspring during gestation, parturition, or through lactation. Certain viruses cross the placental barrier, leading to in utero infection, while others are secreted in milk, providing a post‑natal source of infection. Experimental data demonstrate that up to 30 % of pups born to viremic dams acquire the pathogen.
Ectoparasites, such as fleas, mites, and ticks, serve as mechanical or biological vectors. Parasites feeding on an infected mouse acquire viral particles that can be transferred to subsequent hosts during later blood meals. This indirect route expands the geographic reach of the virus beyond the immediate mouse population.
Environmental persistence contributes to indirect transmission. Viral particles deposited on surfaces, including cage walls, nesting material, and laboratory equipment, remain infectious under appropriate temperature and humidity conditions. Decontamination protocols often require chemical agents capable of inactivating viruses at concentrations exceeding 10⁶ PFU mL⁻¹ to prevent accidental spread.
In summary, mice propagate viral pathogens via direct contact, inhalation of contaminated aerosols, ingestion of fecally contaminated material, maternal transfer, arthropod vectors, and survival of virus in the environment. Each pathway depends on virus-specific shedding patterns, stability characteristics, and host behavior, collectively shaping the dynamics of rodent‑borne viral transmission.