How do mice transmit tick-borne encephalitis? - briefly
Mice serve as reservoir hosts, maintaining the virus in their bloodstream and transferring it to ticks that feed on them; infected ticks subsequently transmit the pathogen to other mammals, including humans. This cycle sustains the disease’s presence in natural habitats.
How do mice transmit tick-borne encephalitis? - in detail
Mice serve as natural reservoir hosts for the tick‑borne encephalitis virus (TBEV). Infected rodents maintain the pathogen in wildlife without showing severe disease, allowing continuous viral circulation.
When an unfed Ixodes tick attaches to a mouse, the blood meal introduces the virus from the rodent’s bloodstream into the tick’s midgut. The virus replicates in the tick’s salivary glands during the subsequent molting stage, reaching infectious concentrations before the next feeding.
Transmission to new hosts occurs during the tick’s next quest for blood. The pathogen is expelled with saliva into the bite wound, infecting the next mammalian or avian host. Co‑feeding ticks—multiple ticks feeding simultaneously on the same mouse—can exchange virus without systemic infection of the rodent, amplifying local transmission.
Key elements of the cycle:
- Rodent infection acquired from a feeding tick.
- Viral replication in the rodent’s peripheral blood.
- Acquisition by a larval or nymphal tick during the blood meal.
- Intramolt viral amplification within the tick.
- Salivary gland infection and subsequent transmission during the next feeding stage.
- Co‑feeding transmission that bypasses high‑level viremia in the host.
These processes sustain TBEV in natural habitats, creating a persistent risk for humans and domestic animals exposed to questing ticks.