Press information

March 09, 2007

New virus causes foetal deaths among pregnant women

The Ljungan virus, which was discovered among wild rodents in the 1990s, may cause previously unexplained cases of foetal death in humans. This is the conclusion of a Swedish-American pilot study, where evidence has been found of Ljungan virus infection in children that have died during late pregnancy. The results are published in the scientific journal Birth Defects Research.

Unborn babies that die in late pregnancy, so called intra-uterine foetal death, cause great trauma to the parents. Often these deaths remain unexplained. When scientists established that intra-uterine foetal death covaries with the presence of rodents in the wild, this was connected to the Ljungan virus. The virus causes among other things diabetes and foetal death in rodents.

“We have investigated ten cases of foetal death during or later than pregnancy week 28. In five of the cases we found the Ljungan virus in the placenta and in four of the cases the virus was also found in the stillborn child. Twenty women with normal pregnancies were in a control group and all of them were free from the virus,” said Bo Niklasson, research director at Apodemus AB.

The results from the pilot study of the afflicted mothers and fetuses is presented by the Swedish research company Apodemus AB in cooperation with scientists at Huddinge hospital, the University of Texas (Galveston), and the University of California (Berkley).

There is a very striking correlation between the prevalence of rodents and the number of cases of intra-uterine foetal death in humans in the same area. This connection is most easily observed in the north of Sweden where the number of rodents varies heavily in cycles of three to four years.

“The correlation between rodent density and number of intrauterine foetal deaths has been difficult to understand but the fact that Ljungan virus has been found in both wild rodents and in patients makes sense,” said Bo Niklasson.

The investigation into the exact role of the Ljungan virus in cases of intrauterine deaths continues on a wide scale both in Sweden and abroad.

“Methods are currently being developed for patient diagnosis and we are also working in areas of therapy and prophylaxis. In addition we are investigating whether the Ljungan virus causes other clinically related phenomena, for instance sudden infant death,” said Bo Niklasson.

Recently another virus – Parvovirus B19 – has been connected to a fraction of the cases of intra-uterine foetal death. The results that are now being presented indicate that the Ljungan virus causes a large part of all the cases.
 

For further information please contact:

Bo Niklasson, physician, professor and Research Director at Apodemus AB
Telephone: +46 708 23 23 23

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The research company Apodemus AB hypothesise that several chronic diseases may be caused by a virus, the Ljungan virus, which is transmitted from animals to humans. The Ljungan virus is carried by bank voles, the most common mammal in Scandinavia.