Nanoviral disease attacking the linguistic systems of Homo sapiens. First identified in year 12 by the Societas Salus Tarautuas as an epidemic spread from a labyrinth exploration team returning to Arx Tarautuas. While originally a major problem, a nanomedical cure was soon found. While the origin is uncertain, the dominant theory is that it is an indigenous Ex Tempore nanoviral strain that has been adapted for military purposes by some Lamplandae group. The incidence has been low since the first outbreak, mainly due to the quick vaccinations of new arrivals.
The Babel virus spreads through the same vectors as the common cold, and initially produces the same symptoms. The virus then traverses the nerve tracts from the speech organs to the brainstem, where it continues along the corticobulbar tract to the speech centers. Here it causes gradual degradation of both speech output and understanding within four days (sometimes limited damage to brainstem nuclei cause a characteristic facial paralysis).
The result is global aphasia: the victim is unable to comprehend, repeat or produce language. This includes reading and writing, and in some people mathematical abilities. They cannot name concepts, and especially highly verbal thinkers suffer from serious cognitive problems.
In about 5% autoimmune reactions cause more widespread brain damage, especially to hearing and motor planning.
Treatment mainly consists of immunization using standard nanoimmune systems. Applying nano-recognizers of the Centurion class that bind the virus and allow the natural immune system to remove them can help already infected people. Local nanochondria upgrades can prevent the spread of the virus inside the neurons. If neural damage has occurred language loss is difficult to treat. Insertion of stem cells, cortical mats or neural regenerators can replace the damaged tissue, which can then be re-trained. Nanoreplacement therapy using a pidgin lobe or vox populi networks can be done, but will produce a noticeably different language use.
Note: while this disease is well controlled in Ex Tempore, resistance to it in the timestream is usually very low. Travelers should take care not to infect people in the timestream, since the risk of an epidemic is very large.