Study links new virus to stillbirths

LOS ANGELES TIMES
Infections by a recently discovered virus might be responsible for a significant fraction of stillbirths, Swedish and American researchers reported in the journal Birth Defects Research.
The Ljungan virus is named after the Swedish river valley where virologist Bo Niklasson of Uppsala University discovered it in voles in 1999. The virus is apparently also common in American rodents, said his co-author, geneticist William Klitz of the Public Health Institute in Oakland, Calif.
Niklasson and Klitz initially observed that the incidence of stillbirths in Sweden was related to the population density of rodents in that country, which varies in a cyclical manner.
Previous studies reported in Birth Defects Research showed that 86 percent of pregnant laboratory mice infected with the virus delivered dead pups, compared with 14 percent of virus-free mice. In the new study, researchers examined stillbirths and placental tissue from humans. They found the virus in four of 10 stillborns that they autopsied and in five of 10 placental tissues. They did not find the virus in any of 20 placental tissues from normal pregnancies.