Group Group IV ((+)ssRNA) Family Picornaviridae Rank Species | Order Picornavirales Genus Parechovirus | |
Similar Parechovirus, Kobuvirus, Aichivirus A | ||
Parechovirus B, more commonly called the Ljungan virus, was first discovered in the mid-1990s after being isolated from a bank vole near the Ljungan river in Medelpad county, Sweden. It has since been established that the Ljungan virus, which is also found in several places in Europe and America, causes serious illness in wild as well as laboratory animals. Several scientific articles have recently reported findings indicating that the Ljungan virus is associated with malformations, intrauterine fetal death, and sudden infant death in humans. In addition, studies are being conducted worldwide to investigate the possible connection of the virus to diabetes, neurological and other illnesses in humans.
The Ljungan virus belongs to the Parechovirus genus of the Picornavirus family. Other members of this viral family include Polio virus, hepatitis A, and the viruses causing the common cold (rhino virus). One of the earliest scientific discoveries regarding the Ljungan virus was that infected wild rodents developed diabetes if they were exposed to stress. This has led to speculation that this disease may be the underlying cause of fluctuating rodent populations in Scandinavia; when rodents increase to high densities, they find it difficult to defend territory and obtain food, and then become more susceptible to predation. This stressful situation results in disease, death and population decline, leading to a pattern of cyclic variation in population size over time.