Zoonotic Ljungan Virus Associated with Central Nervous System Malformations in Terminated Pregnancy

Background:
The Ljungan virus (LV) has been shown to cause central nervous system malformations in laboratory mouse models. The LV has also been associated with intrauterine fetal death in humans. We investigated the presence of LV in a series of human hydrocephaly and anencephaly cases from elective abortions.

Methods:
A series of elective abortions owing to hydrocephaly, anencephaly, and similarly aged trisomy 21 elective abortions as controls were examined for LV by immunohistochemistry and real time RTPCR. A second experiment involved newborn mice exposed to LV. RESULTS: LV was diagnosed in 9 of 10 cases with hydrocephalus and in 1 of 18 trisomy 21 controls by immunohistochemistry. Five of nine cases with anencephaly had a positive PCR result, whereas none of the 12 trisomy 21 available for PCR testing had a positive result. The 47 newborn mice exposed to LV all developed encephalitis, with eight having hydrocephalus. None of the 52 control animals had encephalitis or hydrocephalus.

Conclusion:
The association between LV both hydrocephaly and anencephaly suggests that LV may be playing an important role in AQ3 central nervous system malformations in humans.

Extract:
"The finding that LV causes anencephaly and hydrocephaly in infected laboratory mice stimulated our interest in studying possible associations between LV and CMS in humans (Samsioe et al., 2006). This small pilot study indicates that LV is associated with a substantial proportion of CMS. The present study demonstrated LV in the majority of hydrocephaly cases and in more than half of the anencephaly cases from elective abortions."

Journal Reference:
Bo Niklasson, et al. Zoonotic Ljungan Virus Associated with Central Nervous System Malformations in Terminated Pregnancy. Birth Defects Research (Part A) 00:000–000, 2009. 2009 Wiley-Liss, Inc.